Yucatán recorded nearly a third of Mexico's confirmed flu cases this summer, at four times the national rate, though without a single death. The winter vaccine drive is now underway.Photo: Por Esto!
The state closed the 2026 off-season flu period with 295 confirmed cases, nearly one in three lab-confirmed cases in the entire country, according to federal Health Ministry epidemiological reports. The good news: no one in Yucatán died of the flu during that stretch.
Between May 24 and Oct. 3, health workers in the state logged 2,942 suspected cases of flu-like illness and severe acute respiratory infection. Of those, 295 tested positive, a rate of about 10%.
That was four times the national average of roughly 2.5%. Nationwide, 912 cases were confirmed out of 36,682 suspected patients, and Yucatán alone accounted for about 32.3% of them. Across Mexico, 14 people died of influenza in the same period.
Influenza B led the way
The off-season belonged to influenza B, which made up about 70% of confirmed infections nationwide. Next came A(H3N2) at 23.2%, influenza A with no identified subtype at 3.6%, and A(H1N1) at 3.2%.
Influenza B is often thought of as the milder strain, but doctors don’t brush it off. A U.S. study of hospitalized adults found that patients with influenza B fared about as badly as those with influenza A, with similar rates of intensive care and death.
A familiar pattern
Health officials split the year into two parts. The regular flu season runs from late September or early October through mid-May. The “interseasonal” period covers the warmer months in between, roughly late May through September. In many places, flu fades in summer. In Yucatán, it often doesn’t.
The state has a long record here. During the 2018 off-season, Yucatán accounted for 30 of Mexico’s 56 flu deaths. Last winter, by mid-December 2025, it led the country with nearly 30% of confirmed cases.
A new season, a new vaccine drive
The end of epidemiological week 39 closed the off-season and opened the 2026-2027 flu season. In its first seven days, Yucatán logged 176 suspected cases and two lab-confirmed ones, with no deaths. That works out to a positivity rate of about 1.1%, far below the summer figure, though it is too early to call it a trend.
The new season lines up with Yucatán’s winter vaccination campaign, which began Oct. 12. The state government plans to give 1,017,219 free doses across all 106 municipalities through April 2, 2027. That total covers several vaccines, not just flu.
Of those, 681,791 doses are set aside for influenza, mainly for children, older adults and people with chronic illnesses. The campaign also includes 300,052 COVID-19 doses, 35,376 doses against human papillomavirus (HPV) and protection against respiratory syncytial virus (RSV) for pregnant women.
Vaccines have been in the headlines nationally, too, after a measles outbreak reached all 32 Mexican states.
The coming weeks will show whether Yucatán’s high summer numbers carry into winter, or whether the cooler months and the vaccine drive bring them down.
Fast Facts
- Off-season period: May 24–Oct. 3, 2026
- Confirmed cases in Yucatán: 295 of 2,942 suspected
- Positivity rate: about 10% in Yucatán vs. 2.5% nationally
- Yucatán’s share of Mexico’s confirmed cases: about 32.3%
- Flu deaths: none in Yucatán, 14 nationwide
- Dominant strain: influenza B, about 70% of cases
- Vaccine campaign: Oct. 12, 2026, to April 2, 2027
- Flu doses available in Yucatán: 681,791
- Priority groups: children, older adults, people with chronic illnesses
- Cost: free
With reporting from Por Esto! and Diario de Yucatán, and data from Mexico’s Health Ministry
Yucatán Magazine has the inside scoop on living here. Sign up to get our top headlines delivered to your inbox every week.