Kerala is grappling with a measles outbreak that is spreading across the state, with cases concentrated in the northern districts of Kozhikode, Malappuram and Palakkad. As of 6 November, the Integrated Disease Surveillance Programme (IDSP) had reported 824 confirmed and 1,681 probable measles cases in the state, according to The Hindu, and five measles-related deaths have been reported — though only one of them has been confirmed as caused by measles so far.
What is troubling public-health experts is not only the scale of the outbreak but who is falling ill. Measles in Kerala was once predominantly a disease of children aged one to five. It is now being reported across age groups, including among fully vaccinated people and among infants below nine months — children who are not yet eligible for routine measles vaccination. The state's last major surge was in 2022–23, and experts say the changing profile of the disease calls for a detailed reassessment of its epidemiology.
The numbers so far
The IDSP figures, reported on 8 November, give the clearest picture of the outbreak's scale. A separate report by Kerala Kaumudi on 4 November, drawing on state health department data, put the confirmed count at 538 cases as of October, with more than 1,000 people showing symptoms and four deaths — a reminder that the official tally has been climbing quickly as surveillance catches up.
| Measure | Figure | Source and date |
|---|---|---|
| Confirmed cases | 824 | IDSP, as of 6 November 2026 |
| Probable cases | 1,681 | IDSP, as of 6 November 2026 |
| Measles-related deaths reported | 5 (1 confirmed) | IDSP, as of 6 November 2026 |
| Confirmed cases (earlier count) | 538 | State health department, as of October 2026 |
| Worst-affected districts | Kozhikode, Malappuram, Palakkad | The Hindu |
Among the deaths reported was 15-year-old Dakshith Babu, a student from Thalassery in Kannur district, who died after contracting the disease, according to Kerala Kaumudi. The state's Health Services Director, Dr V. Meenakshi, said most infections were being reported among children who had not received the vaccine.
A disease changing its profile
For decades, measles in India was understood as a childhood illness striking mainly between the ages of one and five. Kerala's current outbreak does not fit that pattern. Cases are appearing in every district and across age groups — among unvaccinated, partially vaccinated and fully vaccinated children, and among infants too young for their first dose.
The shift matters because it challenges the assumptions behind the vaccination schedule itself. Measles vaccination was introduced into India's Universal Immunisation Programme (UIP) in 1985 as a single dose at nine months. A second dose, at 18 months, was added in 2010 to close immunity gaps left by the first dose and to support measles elimination. The nine-month threshold was chosen deliberately: antibodies passed from mother to baby through the placenta can interfere with the vaccine's effect, so the first dose is timed for when that maternal protection has waned.
But if infants are now falling ill before nine months, that timing may no longer be protecting them when they need it most.
Why infants are falling ill before nine months
One explanation put forward by Kerala paediatricians is that mothers of the present generation carry lower levels of measles antibodies than their own mothers did — because they gained immunity through vaccination rather than through natural infection, which typically produces stronger, longer-lasting antibody levels.
"In recent epidemics, we have seen a good number of infants developing measles before nine months, potentially because mothers of the present generation have lower levels of measles antibodies. We also have a chunk of cases among older adults."
— K.K. Purushothaman, former Professor of Paediatrics, Government Medical College, Thrissur
Dr Purushothaman believes the state should consider an additional dose of a measles-containing vaccine under the UIP — either during adolescence or for women before marriage — and says the State Technical Advisory Group on Immunisation should examine the proposal and commission serological studies among adolescents and young women to assess their protective antibody levels.
The concern is supported by findings elsewhere. After major measles outbreaks in Mumbai in 2023, when more than 31% of reported cases were among infants below nine months, a seroprevalence study found that only 66.8% of mothers had adequate measles antibodies to protect their infants.
A World Health Organization informal technical consultation, published in the journal Vaccine in May 2025, acknowledged that women who acquire immunity through vaccination rather than natural infection may transfer lower levels of measles antibodies to their babies. The experts concluded, however, that the evidence was insufficient to change the existing recommendation for the first routine dose at 9–15 months.
What the antibody study found
Research closer to home suggests vaccination history alone may not fully explain the emerging picture. A study by the Rajiv Gandhi Centre for Biotechnology (RGCB), published in JAMA Network Open in August 2025, measured measles antibody levels in 684 children aged four to 18 from Kerala and Tamil Nadu who had received at least two doses of a measles-containing vaccine, as well as in 544 mothers.
| Finding | Result |
|---|---|
| Children lacking protective antibody levels | 8.5% |
| Children testing positive for measles-specific IgM (recent infection) | 89 children (13%) |
| Children with borderline IgM results | 90 children (13.2%) |
| Children who had received a third vaccine dose | 435 (63.6%) |
| Children who had received a fourth dose | 7 |
The researchers interpreted the findings as suggestive of recent measles exposure and possible breakthrough infections — cases in vaccinated children. They stressed, however, that antibody levels alone do not establish whether an individual will develop clinical measles, and that the findings raise questions about the durability and adequacy of vaccine-induced immunity rather than settling them.
Incomplete immunisation still the main driver
Despite the new questions about immunity, incomplete immunisation remains the major driver of outbreaks, experts say. Kerala generally reports around 95% coverage for the first dose of the measles–rubella (MR) vaccine, but coverage of the second dose, given at 18 months, has consistently been lower, at around 85–88%, with some districts reporting still poorer coverage.
The health department has often attributed outbreaks to districts such as Malappuram and Kozhikode, where vaccination gaps are substantial. But experts point out that pockets of under-immunisation exist across the state, and cases are being reported in every district. The RGCB findings also challenge the assumption that high vaccination coverage alone guarantees adequate population immunity.
What is not yet established: only one of the five reported deaths has been confirmed as measles-related, and the figures for confirmed and probable cases are surveillance counts that will be revised as laboratory results come in. Nor is it settled whether breakthrough infections or incomplete coverage is the dominant force behind the current surge — Kerala needs larger epidemiological investigations to establish how many laboratory-confirmed cases occurred among children with two verified vaccine doses, those with partial or no immunisation, and the age break-up of those affected.
The WHO's elimination strategy depends on high two-dose coverage, effective surveillance and rapid outbreak response. Kerala's experience suggests that even a state with strong first-dose coverage can see the virus find the gaps — in unvaccinated children, in infants too young to vaccinate, and possibly in vaccinated children whose antibody levels have faded.
Frequently asked questions
How many measles cases has Kerala reported?
As of 6 November, the Integrated Disease Surveillance Programme had reported 824 confirmed and 1,681 probable cases. Five measles-related deaths have been reported, of which one has been confirmed so far.
Why are infants under nine months getting measles?
Infants below nine months are not yet eligible for routine measles vaccination. Experts say mothers of the present generation may pass on lower levels of protective antibodies than previous generations did, because their own immunity came from vaccination rather than natural infection — leaving some babies unprotected before their first dose.
Does this mean the measles vaccine does not work?
No. The vaccine remains the most effective protection against measles, and most infections in Kerala are among unvaccinated children. The new research raises questions about how long vaccine-induced antibody levels last in some children and whether an extra dose is needed — not about whether vaccination works.
What is being proposed?
Kerala paediatricians have proposed that the state consider an additional dose of a measles-containing vaccine under the immunisation programme, either in adolescence or for women before marriage, and that the State Technical Advisory Group on Immunisation commission serological studies among adolescents and young women.
Is measles rising elsewhere too?
Yes. The United States has reported more than 5,000 measles cases this year, its highest total since 1991, and outbreaks have been reported in several countries — a sign that immunity gaps are a global, not only a Kerala, problem.
Key takeaways
- Kerala has reported 824 confirmed and 1,681 probable measles cases as of 6 November, with five deaths reported and one confirmed.
- The outbreak is no longer confined to children aged one to five: cases are appearing among infants below nine months, fully vaccinated children and older adults.
- Experts say mothers may now pass on weaker antibody protection, leaving infants exposed before their first scheduled dose at nine months.
- A 2025 study of 684 vaccinated children found 8.5% lacked protective antibody levels, raising questions about how durable vaccine-induced immunity is.
- Incomplete immunisation remains the main driver: second-dose coverage in Kerala is around 85–88%, below the roughly 95% first-dose figure.
Kerala now needs larger epidemiological investigations to settle the central question: whether the current surge is driven predominantly by incomplete coverage, or whether additional immunity gaps also need to be addressed. What to watch next is the State Technical Advisory Group on Immunisation's response to the proposal for an additional vaccine dose and for serological studies, the next IDSP case update, and whether the health department's vaccination drives in the northern districts close the coverage gaps that the virus is exploiting.
