Sri Muthukumaran Medical College Hospital and Research Institute, India
Posters & Accepted Abstracts: Virol-mycol
Mumps, long considered a vaccine preventable childhood infection has now caused worldwide re-emergence in vaccinated populations. Thus, a study was done to investigate the cases of vaccine failure among mumps suspect cases in Chennai, India. Results revealed an alarming 90.5 % of vaccinated cases were positive for anti-mumps IgM antibody, indicating that MMR vaccine had failed to offer protection. This is the first report to portray the high prevalence of mumps in vaccinated populations in India. Genotypic characterization of the virus revealed that the circulating strain was genotype C which is distinct from the vaccine strain of genotype N (L-Zagreb). This is also the first report in India to suggest that genotype C was responsible for the present mumps infection. Poor efficacy is a contributing factor to the failure of MMR vaccine and hence, its efficacy was analyzed by determining the seroprotective antibody level. Highest seropositivity (100%) was noticed for rubella, an intermediate number (76% & 92% who received two doses and first doses of MMR) for measles and the lowest (49% & 83%) for mumps virus. This warrants a revisit of vaccine preparation using circulating strains and optimization to improve its efficacy.