Clinical Trial of Measles and Rubella Combined Vaccine Produced by POLYVAC in Vietnam

Abstract

A clinical trial of measles and rubella combined vaccine (MR: MRVAC) produced by POLYVAC was conducted in Vietnam in 2016. A total of 756 subjects were enrolled, and 504 were allocated to MRVAC and 252 to control MR vaccine groups. Paired sera were obtained in 733, and the number of subjects was 403 aged 1 -2 years, 164 aged 2 -18 years, and 166 aged 18 -45 years. Antibodies against measles and rubella viruses were evaluated by EIA. Most subjects had been immunized with a single dose of Expanded Programme on Immunization (EPI) measles vaccine at 9 months of age. Only 41 of 403 subjects aged 1 -2 years were negative for measles antibody before vaccination, and all became seroconverted. A serological response of more than a 2-fold increase against measles was noted in 214 (47%, 95% CI; 42.4% -51.6%) of 458 initially seropositive individuals immunized with MRVAC and 65 (28%, 95% CI; 22.3% -33.8%) of 234 in the control group, and geometric mean titer (GMT) after vaccination was 2 5.49-5.60 in MRVAC and 2 5.03-5.24 in control group. Seroconversion against rubella virus after immunization with MRVAC was noted in 267 (98.5%, 95% CI; 97.1% -100%) of 271 initially seronegative subjects, similar to that after immunization with control group. GMT after immunization with MRVAC was 2 4.88-5.11 significantly lower than that after immunization with control vaccine (2 5.59-5.80 ). Most subject ≥ 2 years of age had rubella antibody because of MR vaccination campaign and no significant serological response was observed in initially seronegatives. MRVAC was highly immunogenic and safe vaccine and the domestic production of MR vaccine would contribute to realizing the goal of eliminating measles and rubella.

Recombinant Measles AIK-C Vaccine Strain Expressing Influenza HA Protein

“…The measles AIK-C strain was developed in the 1970 s and has been used mainly in Japan, Iran, and recently in Vietnam [37][38][39], and is recommended for national immunization practices at one year and 5-6 years in Japan [40]. Immunization with the influenza split vaccine is voluntary for individuals ≥6 months of age and its effectiveness in young infants is limited because of the poor stimulation of vaccine on innate immunity [14,15].…”