Measles outbreak in Mumbai due to low vaccination coverage

One of the biggest impacts of the global pandemic is low routine immunization coverage for children.As according to WHO data As of 23 November 2022, nearly 40 million children worldwide did not receive the measles vaccine last year. As a result, an estimated 9 million people were infected with measles in 2021, resulting in 128,000 deaths.

Mumbai’s ongoing measles epidemic reflects a decline in immunization coverage due to disruptions in immunization services and parents’ reluctance to vaccinate their children. As of 24 November, her 233 cases of measles and 13 deaths in Mumbai. According to recent data, 538 confirmed measles cases have been reported in Maharashtra as of October this year. The states of Bihar, Gujarat, Haryana, Jharkhand and Kerala have also seen an increase in the number of measles cases.

“It is clear that in all such areas affected children are unvaccinated and have low average MRCV coverage. [Measles and Rubella containing vaccine] Evidence from elsewhere suggests that unvaccinated children have nearly a 70% higher risk of death than vaccinated children.

Ironically, even in 2021, when the COVID-19 pandemic peaked in India, measles vaccination coverage in Mumbai was 78%, although it has largely declined after the third wave of the pandemic. In 2022 (until October), which was a burn, he was vaccinated against measles. According to Maharashtra’s health authority, the city has only 41.9% coverage.

As to why measles immunization coverage is low across India yet only six states are reporting an increase in measles cases, Dr Giridhara Babu, an epidemiologist at the Public Health Foundation of India, Bangalore, emailed In an email it said: bias. According to the latest report, measles incidence will increase from 3.37 per million population (October 2020-September 2021) to 8.86 per million population (October 2021-September 2022). ). Burdens are increasing in most states. Care must be taken to ensure that outbreaks are not overlooked in underreported areas. ”

Commenting on the outbreak in Mumbai and the rise in measles cases in several states, Dr Babu said: Out of 100 children, he found that even though 80 were vaccinated with her one dose, only 68 children were immune (85% seroconversion) and susceptible children were among her 100. 22 of them are excluded. If this continues for his two years, the susceptible pool will expand. Therefore, it is critical to maintain high levels of coverage through universal immunization programs and follow up with additional immunization activities to prevent outbreaks. ”

mop up campaign

Maharashtra is now mopping up all children infected with MRCV in parts of Mumbai, where recent measles outbreaks have been reported. The first dose of measles vaccine is given at 9-12 months of age as part of routine immunization programs, but as part of the current strategy, one dose of MRCV is given at 9-12 months of age in affected areas. Administered to all children ages 1-5 years. Recently, the number of measles patients is increasing. This dose will be in addition to the 1st and her 2nd priming schedule.

“In outbreak settings, children under 9 months of age (the recommended age for measles vaccine) are at increased risk of measles. hindu.

The level of protection from measles vaccination depends on the age of vaccination. Scientific evidence suggests that in measles, persistent maternal antibodies influence the infant’s response to vaccination and immune conversion.

“Before 9 months, especially 6 months, maternal antibodies interfere with the immune response to the measles vaccine. Against this background, 9 months of age is considered optimal for measles vaccination in infants,” said the 9-month-old as part of a routine immunization program. Dr. Lahariya said.

The efficacy of measles vaccination is estimated to be about 85% when the first vaccine is given 9 months later. On the second dose, it rises to about 95%, says Dr. Lahariya.

susceptible to infection

A single dose provides adequate protection, and two doses provide complete protection, although a few vaccinated children in Mumbai and Malappuram districts of Kerala are still infected. may be due to failure of seroconversion after vaccination. “The level of antibodies induced by measles vaccination declines over time. , we recommend two doses of the vaccine to prevent outbreaks,” says Dr. Babu.

Population susceptibility to measles depends on uptake of two doses, vaccine efficacy, immunity from previous infections, and maternal antibody protection of the infant. Even though her 80 out of 100 children were vaccinated with her one dose, only 68 children acquired immunity (85% seroconversion) and out of 100 children 22 of her are susceptible to infection. If this continues for her two years, the susceptible pool will expand. Therefore, maintaining high levels of vaccination coverage through universal immunization programs and follow-up with additional immunizations to prevent outbreaks is critical, says Dr. Bab.

infectious virus

Measles is a highly contagious virus and an infected child can spread the virus to 9-10 suspected children. “A measles patient can spread the virus to others from four days before the rash appears to about eight days until the rash lasts four days for him,” he says. “Unless other children have rashes, it is difficult to isolate before the prodromal period, and direct contact with infectious droplets or spread by airborne transmission already occurs in closed environments. would have been.”

“The R effect is the result of crowding and vaccination. 2-3 of the R effective [ability to spread to two-three children] It’s usually reported in an outbreak setting,” says Dr. Lahariya.