The measles and rubella viruses are two highly transmittable diseases that can be prevented with vaccination. Southeast Asia accounted for 33.8% of the 7,549,000 cases of measles reported in 2020 globally. In India, these viruses continue to be a public health burden, as vaccination levels are too low to achieve herd immunity for certain age groups or districts. India also had the second highest number of infants who had not received the first dose of the measles vaccine. Rubella vaccination gaps are also of particular concern as the virus can spread from mother to fetus during pregnancy. India accounts for 40,000 of 105,000 cases of these congenital rubella cases.
In 1985, the Indian universal immunization program introduced the measles vaccine (MCV1). India introduced a second dose of the MCV1 vaccine in 2010, along with campaigns to vaccinate children aged 9 months to 10 years in 14 states where less than 80% of the population received vaccinations for MCV1. The rubella vaccine was not added to the universal immunization program in India until 2016. With the goal of eliminating measles, rubella, and congenital rubella syndrome by 2023, the government utilized a measles-rubella vaccine (MCRV) to conduct measles-rubella supplementary immunization activities (MR-SIAs) to target about 410 million children from 9 months old to 15 years old from 2017 to 2019. During this two year period, these MR-SIAs were completed in 26 of the 28 Indian states (not completed in West Bengal and the Northern Capital Territory of Delhi).
CEID’s Amy Winter worked with a research team to conduct community-based serosurveys (shows population immunity from both vaccination and natural infection) in four districts in India before and after MR-SIAs between March 2018 and March 2020. There were two age groups included in the program, a group of children between 9 months old and less than 5 years old and an older age group of children between 5 years and 15 years old.
Blood samples were collected from 2570 children before the measles-rubella supplementary immunization activity and from 2619 after the vaccine that were tested for measles and rubella antibodies. Thirty subdivisions or village clusters were selected for each district, with a census tract of 120 to 150 households randomly selected from each cluster. For each of these groups of households, thirteen eligible individuals were selected for each age group by random sampling.
The results showed significant increases in population immunity for measles and rubella after the MR-SIAs, though some gaps in immunity remained. Some of these immunity gaps can be attributed to low initial vaccination levels in certain districts before these MR-SIAs. The prevalence of rubella immunity significantly increased in all districts for the younger age group (in Hoshiarpur from 13.0% to 87.2%, in Dibrugarh from 10.6% to 96.5%, in Palghar from 21.9% to 94.6%, and in Kanpur Nagar from 13.9% to 73.3%), as well as the older age group (in Hoshiarpur from 62.2% to 97.0%, in Dibrugarh from 48.7% to 98.2%, in Palghar from 66.5% to 98.2%, and in Kanpur Nagar from 66.8% to 92.0%).
Measles immunity prevalence in the younger age group increased in three districts (in Hoshiarpur from 81.8% to 91.5%, in Dibrugarh from 88.5% to 94.3%, and in Palghar from 83.1% to 96.0%). In Kanpur Nagar, the prevalence did not significantly change, from 80.7% to 80.4%. For the older age group, measles immunity increased in all four districts (in Hoshiarpur from 63.4% to 88.7%, in Dibrugarh from 75.4% to 95.9%, in Palghar from 74.8% to 96.5%, and in Kanpur Nagar from 84.5% to 93.7%).
Overall, many immunity gaps were apparent before the measles-rubella supplementary immunization activity. The MR-SIA significantly increased population immunity for both rubella and measles for the children 9 months to 15 years of age, though some gaps still remained after the intervention. Future research can utilize serosurveys to determine which age groups MR-SIAs should be targeted to by identifying immunity gaps in older populations.
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By: Brenna Daly