Trial Outcomes & Findings for A Safety, Tolerability and Immunogenicity Study of 2 Different Regimens of Tetravalent Ad26.Mos4.HIV Prime Followed by Boost With Tetravalent Ad26.Mos4.HIV Along With Either Clade C gp140 Plus Adjuvant OR With a Combination of Mosaic and Clade C gp140 Plus Adjuvant in Healthy HIV Uninfected Adults (NCT NCT02935686)

Last Updated: 2025-05-25

Results Overview

Number of participants with solicited local and systemic AEs for 7 days post-vaccination 1 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Solicited AEs were precisely local and systemic events for which the participant is specifically questioned and symptoms of which were noted by participant in their diary. Solicited local AEs included injection site pain/tenderness, erythema, and swelling/induration at the study vaccine injection site. Solicited systemic AEs included fever (temperature measurement), fatigue, headache, nausea, myalgia, and chills.

Recruitment status

COMPLETED

Study phase

PHASE1/PHASE2

Target enrollment

155 participants

Primary outcome timeframe

Up to 7 days post-vaccination 1 on Day 1 (up to Day 8)

Results posted on

2025-05-25

Participant Flow

From Week 192 (-4 weeks/+ 4 months), eligible and consenting participants in long-term extension (LTE) phase received late boost vaccination and continued in late boost vaccination phase. Hence, there is an overlap in the duration of LTE and late boost vaccination phase.

Participant milestones

Participant milestones
Measure	Group 1 Main Study and LTE Phase: Ad26.Mos4.HIV + Clade C gp140 Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2 Main Study and LTE Phase: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3 Main Study: Placebo Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 1b: LTE Then Late-boost Ad26.Mos4.HIV + gp140 HIV Bivalent Vaccine Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with Ad26.Mos4.HIV and bivalent gp140 containing adjuvanted protein co-formulation with 80 mcg Clade C protein, 75 mcg Mosaic protein and 425 mcg aluminum (as aluminum phosphate adjuvant) as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.	Group 2b: LTE Then Late-boost Placebo Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study (Week 0 up to Week 72) STARTED	26	103	26	0	0
Main Study (Week 0 up to Week 72) Vaccinated	26	100	26	0	0
Main Study (Week 0 up to Week 72) COMPLETED	19	87	24	0	0
Main Study (Week 0 up to Week 72) NOT COMPLETED	7	16	2	0	0
Long-term Extension (Week 72 - 216) STARTED	14	76	0	0	0
Long-term Extension (Week 72 - 216) Participants Entering LTE and Did Not Receive Late-boost (Weeks 72-216)	3	33	0	0	0
Long-term Extension (Week 72 - 216) COMPLETED	12	63	0	0	0
Long-term Extension (Week 72 - 216) NOT COMPLETED	2	13	0	0	0
Late Boost Vaccination (Week 192 - 288) STARTED	0	0	0	41	13
Late Boost Vaccination (Week 192 - 288) COMPLETED	0	0	0	39	11
Late Boost Vaccination (Week 192 - 288) NOT COMPLETED	0	0	0	2	2

Reasons for withdrawal

Reasons for withdrawal
Measure	Group 1 Main Study and LTE Phase: Ad26.Mos4.HIV + Clade C gp140 Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2 Main Study and LTE Phase: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3 Main Study: Placebo Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 1b: LTE Then Late-boost Ad26.Mos4.HIV + gp140 HIV Bivalent Vaccine Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with Ad26.Mos4.HIV and bivalent gp140 containing adjuvanted protein co-formulation with 80 mcg Clade C protein, 75 mcg Mosaic protein and 425 mcg aluminum (as aluminum phosphate adjuvant) as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.	Group 2b: LTE Then Late-boost Placebo Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study (Week 0 up to Week 72) Adverse Event	1	0	0	0	0
Main Study (Week 0 up to Week 72) Lost to Follow-up	4	1	2	0	0
Main Study (Week 0 up to Week 72) Pregnancy	0	2	0	0	0
Main Study (Week 0 up to Week 72) Withdrawal by Subject	2	9	0	0	0
Main Study (Week 0 up to Week 72) Other	0	1	0	0	0
Main Study (Week 0 up to Week 72) Randomized but not vaccinated	0	3	0	0	0
Long-term Extension (Week 72 - 216) Lost to Follow-up	2	8	0	0	0
Long-term Extension (Week 72 - 216) Withdrawal by Subject	0	4	0	0	0
Long-term Extension (Week 72 - 216) Adverse Event	0	1	0	0	0
Late Boost Vaccination (Week 192 - 288) Adverse Event	0	0	0	0	1
Late Boost Vaccination (Week 192 - 288) Lost to Follow-up	0	0	0	2	1

Baseline Characteristics

A Safety, Tolerability and Immunogenicity Study of 2 Different Regimens of Tetravalent Ad26.Mos4.HIV Prime Followed by Boost With Tetravalent Ad26.Mos4.HIV Along With Either Clade C gp140 Plus Adjuvant OR With a Combination of Mosaic and Clade C gp140 Plus Adjuvant in Healthy HIV Uninfected Adults

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=26 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=100 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3 Main Study: Placebo n=26 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Total n=152 Participants Total of all reporting groups
Age, Continuous	28.7 years STANDARD_DEVIATION 7.07 • n=5 Participants	31.8 years STANDARD_DEVIATION 8.09 • n=7 Participants	30.7 years STANDARD_DEVIATION 10.11 • n=5 Participants	31.1 years STANDARD_DEVIATION 8.34 • n=4 Participants
Sex: Female, Male Female	16 Participants n=5 Participants	59 Participants n=7 Participants	15 Participants n=5 Participants	90 Participants n=4 Participants
Sex: Female, Male Male	10 Participants n=5 Participants	41 Participants n=7 Participants	11 Participants n=5 Participants	62 Participants n=4 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=5 Participants	6 Participants n=7 Participants	4 Participants n=5 Participants	12 Participants n=4 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	24 Participants n=5 Participants	92 Participants n=7 Participants	22 Participants n=5 Participants	138 Participants n=4 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	2 Participants n=7 Participants	0 Participants n=5 Participants	2 Participants n=4 Participants
Race/Ethnicity, Customized Asian	2 Participants n=5 Participants	7 Participants n=7 Participants	2 Participants n=5 Participants	11 Participants n=4 Participants
Race/Ethnicity, Customized Black or African American	10 Participants n=5 Participants	38 Participants n=7 Participants	9 Participants n=5 Participants	57 Participants n=4 Participants
Race/Ethnicity, Customized White	12 Participants n=5 Participants	47 Participants n=7 Participants	12 Participants n=5 Participants	71 Participants n=4 Participants
Race/Ethnicity, Customized Other	2 Participants n=5 Participants	8 Participants n=7 Participants	3 Participants n=5 Participants	13 Participants n=4 Participants
Region of Enrollment KENYA	1 Participants n=5 Participants	4 Participants n=7 Participants	0 Participants n=5 Participants	5 Participants n=4 Participants
Region of Enrollment RWANDA	7 Participants n=5 Participants	26 Participants n=7 Participants	7 Participants n=5 Participants	40 Participants n=4 Participants
Region of Enrollment UNITED STATES	18 Participants n=5 Participants	70 Participants n=7 Participants	19 Participants n=5 Participants	107 Participants n=4 Participants

PRIMARY outcome

Timeframe: Up to 7 days post-vaccination 1 on Day 1 (up to Day 8)

Population: Full analysis set (FAS) included all participants who were randomized and who received at least one dose of study vaccine.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=26 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=100 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=26 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 1 Solicited local AE	21 Participants	78 Participants	6 Participants	—
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 1 Solicited systemic AE	20 Participants	80 Participants	16 Participants	—

PRIMARY outcome

Timeframe: Up to 7 days post vaccination 2 (up to any day from Day 78 to Day 113) (vaccination 2 ranged from Day 78 to 106)

Population: FAS included all participants who were randomized and who received at least one dose of study vaccine. Here, "N" (Overall number of participants analyzed) signifies participants evaluable for this outcome measure.

Number of participants with solicited local and systemic AEs for 7 days post-vaccination 2 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Solicited AEs were precisely local and systemic events for which the participant is specifically questioned and symptoms of which were noted by participant in their diary. Solicited local AEs included injection site pain/tenderness, erythema, and swelling/induration at the study vaccine injection site. Solicited systemic AEs included fever (temperature measurement), fatigue, headache, nausea, myalgia, and chills.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=24 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=98 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=25 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 2 Solicited local AE	19 Participants	66 Participants	5 Participants	—
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 2 Solicited systemic AE	15 Participants	58 Participants	13 Participants	—

PRIMARY outcome

Timeframe: Up to 7 days post vaccination 3 (up to any day from Day 162 to Day 197) (vaccination 3 ranged from Day 162 to 190)

Number of participants with solicited local and systemic AEs for 7 days post-vaccination 3 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Solicited AEs were precisely local and systemic events for which the participant is specifically questioned and symptoms of which were noted by participant in their diary. Solicited local AEs included injection site pain/tenderness, erythema, and swelling/induration at the study vaccine injection site. Solicited systemic AEs included fever (temperature measurement), fatigue, headache, nausea, myalgia, and chills.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=23 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=92 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=25 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 3 Solicited local AE	18 Participants	73 Participants	12 Participants	—
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 3 Solicited systemic AE	10 Participants	55 Participants	8 Participants	—

PRIMARY outcome

Timeframe: Up to 7 days post vaccination 4 (up to any day from Day 330 to Day 365) (vaccination 4 ranged from Day 330 to 358)

Number of participants with solicited local and systemic AEs for 7 days post-vaccination 4 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Solicited AEs were precisely local and systemic events for which the participant is specifically questioned and symptoms of which were noted by participant in their diary. Solicited local AEs included injection site pain/tenderness, erythema, and swelling/induration at the study vaccine injection site. Solicited systemic AEs included fever (temperature measurement), fatigue, headache, nausea, myalgia, and chills.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=19 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=88 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=24 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 4 Solicited local AE	13 Participants	70 Participants	7 Participants	—
Main Study: Number of Participants With Solicited Local and Systemic Adverse Events (AEs) for 7 Days Post-vaccination 4 Solicited systemic AE	11 Participants	53 Participants	6 Participants	—

PRIMARY outcome

Timeframe: Up to 28 days post-vaccination 1 on Day 1 (Up to Day 29)

Population: FAS included all participants who were randomized and who received at least one dose of study vaccine.

Number of participants with unsolicited AEs for 28 days post-vaccination 1 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=26 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=100 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=26 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days Post-vaccination 1	8 Participants	40 Participants	12 Participants	—

PRIMARY outcome

Timeframe: Up to 28 days post vaccination 2 (up to any day from Day 78 to Day 134) (vaccination 2 ranged from Day 78 to 106)

Number of participants with unsolicited AEs for 28 days post-vaccination 2 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=24 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=98 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=25 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days Post-vaccination 2	6 Participants	35 Participants	7 Participants	—

PRIMARY outcome

Timeframe: Up to 28 days post vaccination 3 (up to any day from Day 162 to Day 218) (vaccination 3 ranged from Day 162 to 190)

Number of participants with unsolicited AEs for 28 days post-vaccination 3 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=23 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=92 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=25 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days Post-vaccination 3	5 Participants	38 Participants	8 Participants	—

PRIMARY outcome

Timeframe: Up to 28 days post vaccination 4 (up to any day from Day 330 to Day 358) (vaccination 4 ranged from Day 330 to 358)

Number of participants with unsolicited AEs for 28 days post-vaccination 4 were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=19 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=88 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=24 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days Post-vaccination 4	3 Participants	30 Participants	5 Participants	—

PRIMARY outcome

Timeframe: From Baseline (Day 1) up to Week 72

Population: FAS included all participants who were randomized and who received at least one dose of study vaccine.

Number of participants who discontinued study vaccination due to AEs were reported. An AE is any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the treatment.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=26 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=100 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=26 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants Who Discontinued Study Vaccination Due to AEs	1 Participants	0 Participants	0 Participants	—

PRIMARY outcome

Timeframe: From Baseline (Day 1) up to Week 72

Population: FAS included all participants who were randomized and who received at least one dose of study vaccine.

Number of participants with SAEs were reported. An AE was any untoward medical occurrence in a clinical study administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the study vaccine. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important.

Outcome measures

Outcome measures
Measure	Group 1: Ad26.Mos4.HIV + Clade C gp140 n=26 Participants Participants in the main study received single intramuscular (IM) injection of Ad26.Mos4.HIV vaccine 5\10\^10 viral particles (vp) at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + Clade C glycoprotein 140 vaccine containing 250 micrograms (mcg) of total protein mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 and consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 2: Ad26.Mos4.HIV + Clade C gp140 + Mosaic gp140 n=100 Participants Participants in the main study received single IM injection of Ad26.Mos4.HIV vaccine 5\10\^10 vp at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by Ad26.Mos4.HIV vaccine 5\10\^10 vp + combination of Mosaic gp140 and Clade C gp140 containing 125 micrograms (mcg) of Clade C gp140 and 125 mcg Mosaic gp140 mixed with adjuvant (aluminum phosphate) IM injection at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks). Participants who received all 4 vaccinations and were negative for HIV infection at Week 72 consented separately for an optional long-term extension (LTE) phase after Week 72 and were followed up until Week 216 (for participants who did not enter late boost vaccination phase) and up to any day between Week 188 to Week 208 for those who entered late boost vaccination phase.	Group 3: Placebo n=26 Participants Participants received a single IM injection of placebo matching to Ad26.Mos4.HIV at Weeks 0 and 12 (- 1 week/ + 3 weeks), followed by placebo injections matching to AD26.Mos4.HIV and matching to Clade C + Mosaic gp140 at Weeks 24 (- 1 week/ + 3 weeks) and 48 (- 1 week/ + 3 weeks).	Group 2b: LTE Then LB: Placebo (Previously in Group 2 of Main Study) Participants from Group 1 and 2 of main study that entered the LTE phase were offered to enter in extension of LTE phase (late boost vaccination phase) and received late- boost vaccination with placebo matching to Ad26.Mos4.HIV and matching to gp140 HIV bivalent as IM injection within 4 weeks prior to Week 192 until 4 months after Week 192 (that is, any day from Week 188 to Week 208) and were followed up until Week 288.
Main Study: Number of Participants With Serious Adverse Events (SAEs)	0 Participants	0 Participants	0 Participants	—

PRIMARY outcome

Timeframe: From Baseline (Day 1) up to Week 216

Population: FAS: all participants who were randomized and received at least 1 dose of study vaccine in main study and continued in LTE and did not enter late boost vaccination phase. Due to change in planned analysis, safety data for main study and LTE were combined for Groups 1 and 2 as LTE was a follow-up for participants who were in main study in Groups 1 and 2; no intervention was given in LTE. As both phases involved same participants in continued monitoring, data reflects ongoing safety assessment.

Number of participants with adverse events of special interest (AESIs) were reported. As planned, confirmed HIV infection was the only event assessed as an AESI. AESIs (including potential AESIs) are significant AEs that are judged to be of special interest because of clinical importance, known or suspected class effects, or based on nonclinical signals. AESIs (including potential AESIs) must be reported to the sponsor within 24 hours of awareness irrespective of seriousness (that is, serious and nonserious AEs) or causality.