Does India Need to Rethink MMR Inclusion in the National Immunization Schedule?

Mumps – an acute infectious disease, is caused by an RNA virus from the genus Rubulavirus, family Paramyxoviridae. This virus predominantly targets glandular and nervous tissues. While children aged 5-9 years of age are most affected, the disease can also infect older individuals––where it tends to be more severe. Mumps can present both clinically and subclinically – subclinical cases accounting for 30-40% of all instances. 

In children, the primary symptoms are pain and swelling in one or both parotid glands, resulting in puffy cheeks and a tender jaw. Some children may also experience an earache on the affected side before the swelling begins. In severe cases, sublingual and submandibular glands may also be involved. Other systemic signs are fever and headache, which may accompany the more severe presentations. Parotid swelling typically subsides within 1-2 weeks.

Complications from mumps can include – orchitis, ovaritis, pancreatitis, meningoencephalitis, thyroiditis, neuritis, hepatitis, and myocarditis. Up to 15% of the patients may develop meningitis, and rare cases can result in sensorineural deafness, facial palsy, polyarthritis, and hydrocephalus. Mumps during pregnancy, particularly in the first trimester, pose a serious risk, potentially leading to spontaneous abortions in approximately 25% of cases.

Mumps – a highly infectious disease preventable by vaccination, has secondary attack rates as high as 86%. In India, mumps is not included in the Integrated Disease Surveillance Program (IDSP) but can be reported under the "other diseases" category. From September 2009 until May 2015, 2,892 mumps cases were reported in India, and between July and September 2017, 15 outbreaks comprising 260 cases were documented. Recent data from the Global Health Observatory indicated 764 cases between 2021 and 2022 – highlighting the significant burden of mumps in India, particularly among children. Frequent outbreaks, such as the one in Kerala in March 2023 with 2,505 cases, underscore the cyclical nature of the infection and factors like high communicability, non-immunized children, and poor living conditions.

Vaccination is the most effective preventive method–specifically the Measles, Mumps, and Rubella (MMR) vaccine. Research indicates that the MMR vaccine effectively induces seroconversion, with the protective efficacy of mumps antibodies at 78% after the first dose and 88% after the second dose. The Government of India (GoI) has opted to include the bivalent Measles-Rubella (MR) vaccine in its Universal Immunization Program (UIP) due to the perceived lower public health threat of mumps, lack of comprehensive data on its community burden, and higher cost of the MMR vaccine. Experts argue that incorporating the MMR vaccine could prevent significant outbreaks and provide extra protection using the exact logistics.

Including the mumps antigen in the National Immunization Schedule would be beneficial, offsetting vaccine costs and reducing the disease burden. Studies have shown that the MMR vaccine maintains a consistent protective immune response and that delays in its inclusion could leave many births unprotected. 

Ensuring vaccine security through reliable supply and accurate forecasting is crucial. Economic evaluations have demonstrated cost savings from implementing a two-dose MMR vaccination program. Therefore, India should reconsider incorporating the MMR vaccine to mitigate mumps outbreaks and safeguard public health. By promoting MMR vaccine uptake, we can significantly reduce the risk of mumps and enhance public health outcomes nationwide.

Source: Kumari S, Gupta S, Singh M, Kishore J. Epidemiology International (E-ISSN: 2455-7048). 2024 May 18;9(1):1-4.