Continuing mumps outbreak in Keralam leads to renewed demand for MMR vaccine

The continuing mumps outbreak in Keralam, which began in late 2023 and has persisted into 2026, has renewed demands for including the mumps-measles-rubella (MMR) vaccine in the Universal Immunisation Programme (UIP). Outbreaks have forced the closure of schools and hostels for weeks in Alappuzha, Thrissur and Kottayam.

The demand has gained strength following studies from Keralam documenting immunity gaps among children, complications that can cause long-term disability, and genetic differences between the circulating mumps virus and the strain used in the vaccine, indicating how the continued exclusion of the MMR vaccine from the UIP represented an important gap in disease prevention.

From an annual average of over 2,000 cases, mumps infections began surging in November 2023. Keralam reported 74,907 cases in 2024 and 26,462 in 2025. A further 6,606 cases have been reported so far this year.

Low priority

Despite being vaccine-preventable, mumps has remained a relatively low priority in India’s immunisation policy, largely because of its low mortality. Although a time-tested combined MMR vaccine is available, the UIP provides two doses of the measles-rubella (MR) vaccine, which does not protect against mumps.

The Indian Academy of Paediatrics (IAP) has long recommended MMR in place of MR, a vaccine combination available to children through the private sector since the 1980s. It has argued that mumps’ public health significance is underestimated because clinical cases, complications and long-term outcomes are inadequately documented.

With outbreaks also occurring regularly in other States, several have urged the Centre to include MMR in the UIP.