Trial Outcomes & Findings for Vaccine Effectiveness of RV1 in a Naïve Population (NCT NCT01467037)

Results Overview

RV1 vaccine effectiveness (VE) was investigated using a subset of active surveillance participants age-eligible to receive 2-doses of RV1 vaccine, defined as participants (i) \<15 weeks of age as of program implementation (November 1, 2011), and (ii) ≥16 weeks of age at symptom onset. These ages corresponded to the maximum recommended age of administration for the first RV1 dose at program implementation, and the recommended age of second dose administration, respectively. We estimated RV1 VE of 2- versus 0-doses and ≥1- versus 0-doseto prevent rotavirus hospitalization or emergency visits. Only valid RV1 vaccinations administered ≥14 days prior to symptom onset were considered. Children vaccinated with RV5 (private market,minimal penetrance) were excluded.

Recruitment status

COMPLETED

Target enrollment

374 participants

Primary outcome timeframe

From February 1, 2012 to May 31, 2014

Results posted on

2016-04-19

Participant Flow

We conducted prospective, active surveillance for acute rotavirus gastroenteritis at The Montreal Children's Hospital and Centre Hospitalier Universitaire Sainte-Justine, located in Montreal, and Centre Hospitalier Universitaire de Sherbrooke, located in Sherbrooke.

Participant milestones

Participant milestones
Measure	Vaccine Effectiveness Study Population Among patients eligible for active surveillance of acute gastroenteritis, patients aged \<15 months at RV1 program implementation (November 1, 2011), AND aged ≥16 weeks at symptom onset
Overall Study STARTED	374
Overall Study COMPLETED	374
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Vaccine Effectiveness of RV1 in a Naïve Population

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Rotavirus-negative n=342 Participants All stool samples were initially tested for rotavirus via enzyme immunoassay. Patients with a negative result are included in this group.	Rotavirus -Positive n=32 Participants All stool were initially tested for rotavirus via enzyme immunoassay. Rotavirus-positives were confirmed via real-time reverse-transcriptase polymerase chain reactions (RT-PCR). RT-PCR results were used in the event of discordant EIA results. Rotavirus genotyping was performed.	Total n=374 Participants Total of all reporting groups
Rotavirus vaccination RV-vaccination 0 dose	62 participants n=5 Participants	24 participants n=7 Participants	86 participants n=5 Participants
Rotavirus vaccination RV-vaccination 1-dose	26 participants n=5 Participants	1 participants n=7 Participants	27 participants n=5 Participants
Rotavirus vaccination RV-vaccination ≥2 doses	254 participants n=5 Participants	7 participants n=7 Participants	261 participants n=5 Participants
Age, Continuous	12.6 months STANDARD_DEVIATION 6.3 • n=5 Participants	16.6 months STANDARD_DEVIATION 6.5 • n=7 Participants	13 months STANDARD_DEVIATION 6.4 • n=5 Participants
Sex: Female, Male Female	154 Participants n=5 Participants	20 Participants n=7 Participants	174 Participants n=5 Participants
Sex: Female, Male Male	188 Participants n=5 Participants	12 Participants n=7 Participants	200 Participants n=5 Participants
Region of Enrollment Canada	342 participants n=5 Participants	32 participants n=7 Participants	374 participants n=5 Participants

PRIMARY outcome

Timeframe: From February 1, 2012 to May 31, 2014

Population: Rotavirus vaccination history by rotavirus disease status among matched VE participants

RV1 vaccine effectiveness (VE) was investigated using a subset of active surveillance participants age-eligible to receive 2-doses of RV1 vaccine, defined as participants (i) \<15 weeks of age as of program implementation (November 1, 2011), and (ii) ≥16 weeks of age at symptom onset. These ages corresponded to the maximum recommended age of administration for the first RV1 dose at program implementation, and the recommended age of second dose administration, respectively. We estimated RV1 VE of 2- versus 0-doses and ≥1- versus 0-doseto prevent rotavirus hospitalization or emergency visits. Only valid RV1 vaccinations administered ≥14 days prior to symptom onset were considered. Children vaccinated with RV5 (private market,minimal penetrance) were excluded.

Outcome measures

Outcome measures
Measure	Rotavirus-negative n=156 Participants All stool samples were initially tested for rotavirus via enzyme immunoassay. Patients with a negative result are included in this group.	Rotavirus-positive n=30 Participants All stool were initially tested for rotavirus via enzyme immunoassay. Rotavirus positives were confirmed via realtime reversetranscriptase polymerase chain reactions (RTPCR). RTPCR results were used in the event of discordant EIA results. Rotavirus genotyping was performed.
Matched VE Participants 0-Doses	26 participants	22 participants
Matched VE Participants 1 Dose	16 participants	1 participants
Matched VE Participants 2 Doses	114 participants	7 participants

OTHER_PRE_SPECIFIED outcome

Timeframe: From February 1, 2012 to May 31, 2014

RV1 vaccine effectiveness (VE) was investigated using a subset of active surveillance participants age-eligible to receive 2-doses of RV1 vaccine, defined as participants (i) \<15 weeks of age as of program implementation (November 1, 2011), and (ii) ≥16 weeks of age at symptom onset. These ages corresponded to the maximum recommended age of administration for the first RV1 dose at program implementation, and the recommended age of second dose administration, respectively. Only valid RV1 vaccinations administered ≥14 days prior to symptom onset were considered. RV1 VE was estimated as (1 - exposure odds ratio) × 100. Based upon our sampling scheme, the exposure odds ratio from our analyses approximates the rate ratio.

Outcome measures

Outcome measures
Measure	Rotavirus-negative n=169 Participants All stool samples were initially tested for rotavirus via enzyme immunoassay. Patients with a negative result are included in this group.	Rotavirus-positive n=186 Participants All stool were initially tested for rotavirus via enzyme immunoassay. Rotavirus positives were confirmed via realtime reversetranscriptase polymerase chain reactions (RTPCR). RTPCR results were used in the event of discordant EIA results. Rotavirus genotyping was performed.
Vaccine Effectiveness of RV1	91.2 adjusted VE Interval 61.6 to 98.0	92.5 adjusted VE Interval 69.3 to 98.2

Adverse Events

Vaccine Effectiveness Study Population

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr Caroline Quach, Pediatric Infectious Diseases Consultant & Medical Microbiologist

McGill University Health Centre

Phone: 514-934-1934

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place