New York City’s childhood vaccination rates have slipped measurably, with roughly one in three 2-year-olds not fully immunized as of March 2026, according to new data — a decline that has city health officials warning about renewed measles risk and launching a fresh campaign to get parents to catch their children up.

The numbers, reported in April 2026, show erosion in the routine immunization series the city tracks. About one in three children had not received all seven recommended vaccine series by age 2. For measles specifically, the share of children 24 to 35 months who had received at least one MMR dose by their second birthday fell from 93% in 2024 to 89% in 2025.

A small but ominous measles count

The coverage drop matters because measles has reappeared. As of late May 2026, New York City had recorded six confirmed measles cases for the year, with six more confirmed elsewhere in the state — 12 statewide. The raw totals are small, but measles is among the most contagious pathogens known, and herd immunity erodes quickly when first-dose coverage falls below the mid-90s.

City epidemiologists have stressed that even small percentage-point declines carry outsized consequences in a population the size of New York’s, translating into thousands more children who could fall ill if the virus is introduced and spreads. The cautionary precedent is recent: the 2018–2019 measles outbreak centered in Brooklyn and Rockland County produced 649 cases in New York City and forced an emergency vaccination order.

The city’s response

In response to the slipping rates, the Department of Health and Mental Hygiene launched a vaccination media campaign urging parents to ensure their children are up to date on routine immunizations, with particular emphasis on MMR. The push targets the delays that the data suggest are driving much of the decline — children whose shots have been postponed rather than refused outright — and aims to close the gap before measles or other vaccine-preventable diseases gain a foothold.

The trend mirrors a national post-pandemic dip in childhood immunization, but officials note that New York’s density and international connectivity make it especially vulnerable to importation. Schools and day cares remain a key enforcement point: New York requires standard immunizations for attendance, and the state eliminated non-medical exemptions in 2019 after the last outbreak.

A maternal- and child-health flashpoint

The vaccination data surfaced alongside broader concern about maternal and child health in the city. State and city programs — from the Title V Maternal and Child Health block grant to school-based health centers — are simultaneously navigating budget pressure, even as officials lean on those same channels to reach families with vaccination messaging.

For the Mamdani administration, which took office Jan. 1, 2026, the slipping rates present an early public-health test. The city’s tools are familiar — outreach, school requirements, accessible clinics — but the window to act narrows each time coverage drops another point and another measles case is confirmed.

Verification

Frequently Asked Questions

How much have NYC childhood vaccination rates dropped?
As of March 2026, about one in three NYC 2-year-olds had not received all seven recommended vaccine series. For measles specifically, first-dose MMR coverage among children 24–35 months fell from 93% in 2024 to 89% in 2025.
How many measles cases has New York seen in 2026?
As of late May 2026, NYC had six confirmed measles cases and New York State had six more outside the city, for 12 statewide — small numbers, but enough to worry officials given declining immunity.
What is the city doing about it?
The Department of Health and Mental Hygiene launched a vaccination media campaign urging parents to catch their children up on routine immunizations, including MMR.
Why are even small drops concerning?
Measles is among the most contagious diseases known. In a city of NYC's size, even a few percentage points of lost coverage translate to thousands more vulnerable children. The 2019 NYC outbreak produced 649 cases.