TITLE:
Clinical Trial of Measles and Rubella Combined Vaccine Produced by POLYVAC in Vietnam
AUTHORS:
Nguyen Dang Hien, Nguyen Thuy Huong, Ngo Thu Huong, Pham Thi Phuong Thao, Dinh Hong Duong, Nguyen Xuan Dong, Tomio Lee, Takashi Ito, Tetsuo Nakayama
KEYWORDS:
Measles Vaccine, Rubella Vaccine, MR Combined Vaccine, Elimination of Measles and Rubella
JOURNAL NAME:
Open Journal of Pediatrics,
Vol.8 No.2,
June
21,
2018
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 25.49-5.60 in MRVAC and 25.03-5.24 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 24.88-5.11 significantly
lower than that after immunization with control vaccine (25.59-5.80).
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.