Trial Outcomes & Findings for Responses to Rabies Vaccine in Adults With or Without Antibiotics (NCT NCT03557008)

Last Updated: 2023-06-08

Results Overview

Antibody titers are examined by direct comparison of antibody titers in the blood. Rabies specific Immunoglobulin G (IgG) endpoint titer was measured by ELISA. The endpoint titer is defined as the reciprocal of the highest plasma dilution that gives a reading above the cutoff values. The cutoff is set based on the average plus 3 times the standard deviation of the reading of 1:160 dilution of baseline plasma.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

37 participants

Primary outcome timeframe

Day 28

Results posted on

2023-06-08

Participant Flow

Participant enrollment began July 5, 2018 and all follow up for the primary outcome measure was complete by June 2, 2022. Participants were enrolled at the Hope Clinic of the Emory Vaccine Center in Atlanta, Georgia, USA.

Participant milestones

Participant milestones
Measure	Rabies Vaccine With Antibiotics Participants in this group received the rabies vaccines as well as an antibiotic regimen consisting of metronidazole, vancomycin, and neomycin sulfate.	Rabies Vaccine Participants in this group received the rabies vaccine.
Overall Study STARTED	19	18
Overall Study COMPLETED	14	15
Overall Study NOT COMPLETED	5	3

Reasons for withdrawal

Reasons for withdrawal
Measure	Rabies Vaccine With Antibiotics Participants in this group received the rabies vaccines as well as an antibiotic regimen consisting of metronidazole, vancomycin, and neomycin sulfate.	Rabies Vaccine Participants in this group received the rabies vaccine.
Overall Study Withdrawal by Subject	2	2
Overall Study Early termination from study	3	1

Baseline Characteristics

Responses to Rabies Vaccine in Adults With or Without Antibiotics

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Rabies Vaccine With Antibiotics n=19 Participants Participants in this group received the rabies vaccines as well as an antibiotic regimen consisting of metronidazole, vancomycin, and neomycin sulfate.	Rabies Vaccine n=18 Participants Participants in this group received the rabies vaccine.	Total n=37 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	19 Participants n=5 Participants	18 Participants n=7 Participants	37 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Continuous	32.42 years STANDARD_DEVIATION 7.75 • n=5 Participants	32.50 years STANDARD_DEVIATION 6.58 • n=7 Participants	32.46 years STANDARD_DEVIATION 7.31 • n=5 Participants
Sex: Female, Male Female	11 Participants n=5 Participants	11 Participants n=7 Participants	22 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	7 Participants n=7 Participants	15 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants	2 Participants n=7 Participants	3 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	18 Participants n=5 Participants	16 Participants n=7 Participants	34 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	3 Participants n=5 Participants	0 Participants n=7 Participants	3 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	10 Participants n=5 Participants	10 Participants n=7 Participants	20 Participants n=5 Participants
Race (NIH/OMB) White	6 Participants n=5 Participants	8 Participants n=7 Participants	14 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	19 Participants n=5 Participants	18 Participants n=7 Participants	37 Participants n=5 Participants

PRIMARY outcome

Timeframe: Day 28

Population: This analysis includes participants who completed the Day 28 study visit.

Outcome measures

Outcome measures
Measure	Rabies Vaccine With Antibiotics n=14 Participants Participants in this group received the rabies vaccines as well as an antibiotic regimen consisting of metronidazole, vancomycin, and neomycin sulfate.	Rabies Vaccine n=15 Participants Participants in this group received the rabies vaccine.
Antibody Titers	217.39 IU/mL Standard Deviation 262.99	805.64 IU/mL Standard Deviation 943.85

PRIMARY outcome

Timeframe: Day 28

Population: This analysis includes participants who completed the Day 28 study visit.

Participants are categorized as achieving seropositivity if rabies specific IgG endpoint titer is present.

Outcome measures

Outcome measures
Measure	Rabies Vaccine With Antibiotics n=14 Participants Participants in this group received the rabies vaccines as well as an antibiotic regimen consisting of metronidazole, vancomycin, and neomycin sulfate.	Rabies Vaccine n=15 Participants Participants in this group received the rabies vaccine.
Proportion of Participants Achieving Seroprotection	14 Participants	15 Participants

Adverse Events

Rabies Vaccine With Antibiotics

Serious events: 0 serious events

Other events: 2 other events

Deaths: 0 deaths

Rabies Vaccine

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Rabies Vaccine With Antibiotics n=19 participants at risk Participants in this group received the rabies vaccines as well as an antibiotic regimen consisting of metronidazole, vancomycin, and neomycin sulfate.	Rabies Vaccine n=18 participants at risk Participants in this group received the rabies vaccine.
Gastrointestinal disorders Diarrhea	5.3% 1/19 • Information on adverse events was collected from the time when the study intervention began through Day 56 of the study.	0.00% 0/18 • Information on adverse events was collected from the time when the study intervention began through Day 56 of the study.
Infections and infestations Upper respiratory infection	5.3% 1/19 • Information on adverse events was collected from the time when the study intervention began through Day 56 of the study.	5.6% 1/18 • Information on adverse events was collected from the time when the study intervention began through Day 56 of the study.

Additional Information

Nadine Rouphael, MD

Emory University

Phone: 404-712-1435

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place