Between March 2024 and March 2025, the State-Degree Viral Diagnostic and Analysis Laboratory (SL-VRDL) on the ICMR–NIV Kerala Unit examined 197 suspected circumstances, of which 58 had been confirmed by way of qRT-PCR.
Printed Aug 07, 2026 | 1:53 PM ⚊ Up to date Aug 07, 2026 | 1:53 PM
Vaccination with the MMR vaccine is the simplest approach to stop mumps infections. (Shutterstock)
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Synopsis: Kerala’s extended mumps outbreak has taken a brand new flip, with researchers detecting a beforehand unreported virus genotype within the state, including to issues over the illness’s fast unfold. The discovering has additionally put a renewed concentrate on vaccine coverage, outbreak surveillance and the rising demand to incorporate the MMR vaccine within the common immunisation programme.
For greater than two years, Kerala’s well being officers and researchers have been making an attempt to grasp an uncommon surge of a contagious illness: mumps.
What was as soon as thought of a typical childhood sickness has returned on a a lot bigger scale, spreading properly past youngsters and more and more affecting adolescents and younger adults.
Circumstances shot up from simply 2,324 in 2023 to over 70,000 in 2024, and the virus has continued to flow into this 12 months, with 5,779 infections reported in 2026, together with 341 in July and 43 circumstances this month (as much as 5 August).
Now, a contemporary discovering has added one other piece to the puzzle.
Researchers have discovered that Kerala will not be coping with only one pressure of the virus, as beforehand believed.
One other pressure can also be circulating within the state.
The invention has drawn consideration as a result of the mumps vaccine extensively utilized in India is predicated on a specific pressure, elevating questions on whether or not this mismatch helps the virus proceed to unfold, significantly in crowded settings comparable to colleges and schools.
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Presence of genotype C and questions of outbreak
The primary genomic proof of mumps virus genotype C circulating in Kerala has been reported by researchers, a discovering that would strengthen efforts to trace the virus and assess the effectiveness of current vaccination methods.
The study, carried out by researchers on the ICMR–Nationwide Institute of Virology (NIV), Kerala Unit, Alappuzha, discovered that some mumps virus samples subjected to whole-genome sequencing belonged to genotype C. The findings have been printed in Elsevier’s An infection, Genetics and Evolution journal in July.
Mumps is a extremely contagious viral illness that primarily impacts the salivary glands.
Whereas it’s often gentle and self-limiting, it may well sometimes result in severe problems, together with encephalitis, listening to loss and orchitis, a painful irritation of the testicles seen in round one in 5 contaminated younger grownup males.
The examine comes towards the backdrop of a pointy rise in reported mumps circumstances in Kerala since 2024.
Between March 2024 and March 2025, the State-Degree Viral Diagnostic and Analysis Laboratory (SL-VRDL) on the ICMR–NIV Kerala Unit examined 197 suspected circumstances, of which 58 had been confirmed by way of qRT-PCR (quantitative reverse transcription polymerase chain response, a technique to detect and quantify RNA in a pattern).
Most infections had been reported amongst youngsters aged 5-9 years and adolescents between 10 and 19 years.
Then, a subset of the confirmed samples was chosen for whole-genome sequencing to grasp the molecular epidemiology of the virus.
In response to lead creator B Anukumar of the ICMR–NIV Kerala Unit, elevated reporting of mumps circumstances throughout the state prompted enhanced laboratory surveillance, enabling researchers to characterise the genetic range of the circulating strains.
The genomic evaluation confirmed that the chosen strains differed from the L-Zagreb vaccine pressure, which belongs to genotype N and is usually utilized in India.
The chosen samples had been recognized as genotype C.
Researchers, nonetheless, cautioned that the organic significance of those genetic variations stays unclear and requires additional investigation.
The mumps virus has just one serotype, however variations in its small hydrophobic (SH) gene permit it to be labeled into 12 distinct genotypes, assigned letters from A to N (excluding E and M).
The researchers mentioned the findings underscore the significance of continued molecular surveillance to watch viral evolution and perceive whether or not genetic modifications may have implications for vaccine efficiency. In addition they mentioned the proof provides to the case for evaluating the inclusion of a mumps-containing vaccine within the Common Immunisation Programme (UIP).
The examine was supported beneath the Virus Analysis and Diagnostic Laboratory (VRDL) scheme of the Division of Well being Analysis, Ministry of Well being and Household Welfare.
Additionally Learn: Silent health crisis in Kerala’s tribal communities: One in two adults live with multiple chronic diseases
Examine bats for MMR vaccine in UIP
One other essential facet of the examine is its advice to incorporate the measles-mumps-rubella (MMR) vaccine in UIP, saying it may play a key function in decreasing the rising illness burden.
The examine argues that India continues to have a big mumps burden and says the exclusion of mumps vaccination from the nationwide immunisation schedule stays a niche in illness prevention. It recommends introducing a mumps-containing vaccine, ideally the MMR vaccine, beneath the UIP.
In the meantime, the researchers mentioned the latest rise in mumps circumstances in Kerala can’t be attributed solely to genetic modifications within the virus or vaccine failure.
Though the circulating virus strains differ genetically from the vaccine pressure, the examine cautioned towards treating this as proof of decreased vaccine safety within the absence of vaccination information, immunological knowledge and vaccine effectiveness research.
The findings level as a substitute to a mixture of things, together with gaps in immunisation protection and a rising pool of inclined people.
In Kerala, mumps vaccination was accessible till 2017 earlier than it was discontinued, a transfer the researchers say could have contributed to elevated susceptibility amongst youngsters and adolescents.
Nevertheless, the absence of vaccination historical past for many sufferers within the examine prevented an evaluation of breakthrough infections.
Kerala had briefly integrated the MMR vaccine into its immunisation programme in 2014 by changing the second dose of the measles vaccine administered at 18 months. The transfer was geared toward strengthening safety towards rubella. Nevertheless, the state reverted to the Centre’s schedule in 2017 after the nationwide rollout of the Measles-Rubella (MR) vaccine beneath the UIP. The MR vaccine, given at 9 and 15 months, protects towards measles and rubella however doesn’t cowl mumps.
Referring to earlier seroprevalence knowledge from Vellore, the researchers mentioned continued publicity to the virus throughout age teams factors to ongoing neighborhood transmission and gaps in herd immunity.
Additionally Learn: South India dominates India’s dengue burden; Tamil Nadu reports most cases, Kerala most deaths
The ignored burden of mumps
On the identical time, the resurgence of mumps in Kerala has as soon as once more introduced into focus the long-pending demand to incorporate the MMR vaccine within the UIP, with paediatricians and public well being specialists arguing that the illness has lengthy been underestimated in India.
Though mumps is a vaccine-preventable illness, it has by no means been included within the nationwide immunisation schedule.
The illness was historically seen as having low public well being significance as a result of it hardly ever causes deaths.
Nevertheless, the Indian Academy of Paediatrics (IAP) has constantly maintained that this evaluation overlooks the true burden of the illness, pointing to poor documentation of circumstances, insufficient follow-up of sufferers, restricted reporting of problems and the absence of complete research.
India additionally lacks nationally consultant knowledge on the incidence of mumps, whereas its long-term well being results, significantly these affecting the reproductive system, stay insufficiently studied.
With repeated outbreaks now being reported, Kerala has written to the Centre in search of the substitute of the MR vaccine with the MMR vaccine beneath the nationwide programme.
The demand has discovered help past Kerala.
Earlier in 2024, officers of the Tamil Nadu Directorate of Public Well being and Preventive Drugs strongly argued for the inclusion of the MMR vaccine within the UIP.
They famous that whereas youngsters beneath the nationwide programme obtain safety towards measles and rubella, the mumps element stays accessible solely by way of vaccines within the non-public sector, inserting it past the attain of a giant part of the nation’s youngsters.
Public well being specialists level out that the absence of routine immunisation towards mumps has left successive generations of kids weak to periodic outbreaks. Earlier than vaccination turned accessible, mumps usually resurfaced in epidemic cycles each 4 to 5 years. Elements comparable to overcrowding, poor sanitation and uneven entry to healthcare proceed to facilitate transmission in lots of components of the nation.
Specialists additionally warn that the illness will not be all the time benign.
In addition to inflicting outbreaks in colleges and communities, mumps can result in problems comparable to orchitis, which has been related to subfertility, decreased sperm rely and, in some circumstances, infertility.
They argue that wider use of the MMR vaccine wouldn’t solely cut back infections and problems but in addition reduce the monetary burden on households throughout recurring outbreaks.
The researchers additionally careworn the necessity for sustained molecular surveillance and vaccine effectiveness research to find out whether or not the genetic variations recognized in circulating strains have any affect on safety provided by current vaccines.
