A cross-sectional study to assess levels of antibodies against Pentavalent, Measles-Rubella vaccine and Respiratory Syncytial Virus among the rural population of Maharashtra

India has made significant strides in expanding immunisation coverage through the Universal Immunisation Programme (UIP). Since the launch of the Expanded Program of Immunisation in 1978, there have been several additions of vaccines and improvements in the schedule. In 2010, the Indian Government introduced a second dose of Measles-containing vaccine, with additional catch-up campaigns targeting children aged 9 months to 10 years in 14 states where MCV1 coverage was less than 80%. To improve the immunization coverage more than 90%, Mission Indradhanush was launched in 2014. Although full immunisation coverage of children 12-23 months was 76.6% as per the National Family Health Survey (NFHS), coverage for the second dose of the measles-containing vaccine in children 24-35 months was only 31.9%.[i] After successfully eliminating Polio, India now targets eliminating Measles. India is striving hard to improve vaccination coverage; however, achieving equitable access and ensuring sustained protection against vaccine-preventable diseases (VPDs) remains a critical challenge, particularly among marginalised rural populations.

Along with vaccination coverage, development of adequate immunity in response to the vaccination is also essential for good vaccine effectiveness. Ideally, an effective vaccination programme should increase the number of individuals with positive serological immunity, reaching or exceeding the herd immunity threshold. Since vaccination programs alter the immunity of both vaccinated and unvaccinated populations, sero-epidemiology is crucial for assessing their effects.Data from these surveys can be used to gauge the country’s immunisation programme’s effectiveness and identify susceptible groups for intervention. Seroprevalence of various vaccine-preventable diseases is essential. Thus this study is planned to address the critical knowledge gap regarding the trend of persistence of vaccine-induced immunity against key childhood diseases (diphtheria, tetanus, pertussis, H. influenzae type b (Hib), hepatitis B, measles and rubella) and to assess the seroprevalence of respiratory syncytial virus (RSV) antibodies in rural population.