Health workers in São Paulo administered 109,584 vaccine doses on Friday during a citywide immunization drive aimed at curbing a resurgence of measles.
The single-day total represents the highest daily tally recorded since the municipal campaign began, according to figures released by the São Paulo City Hall. The Friday operation administered 84,632 doses of measles vaccine alongside 24,952 doses protecting against other infectious diseases.
The drive forms part of the Multi-Vaccination Campaign - Keep an Eye on the Card 2026, organized by the São Paulo Municipal Health Secretariat. Since launching on August 3, health workers across the municipality have administered a cumulative 412,091 vaccine doses, comprising 292,701 measles shots and 119,390 doses of other routine vaccines.
The effort builds on a broader measles vaccination intensification strategy that municipal health officials initiated on June 27. Under the expanded strategy, eligibility for measles immunization has been broadened to cover all residents between the ages of six months and 59 years.
Vaccine access and digital tracking
Residents can receive vaccines at Basic Health Units across the city from Monday to Friday between 7:00 a.m. and 7:00 p.m. On Saturdays, immunization services operate during the same hours at Integrated Medical Ambulatory facilities and combined health units. Basic Health Units serve as primary care clinics within Brazil's public healthcare network, known as the Unified Health System.
To help residents navigate clinic availability, health authorities activated real-time tracking on the Keep an Eye on the Line online platform on Wednesday, August 5. The tool allows the public to check measles vaccine availability at local clinics during operational hours, while clinic locations can be retrieved through the city's Health Search portal.
Impending D-Day and infant protocols
Municipal authorities said the measles vaccination campaign will continue through September 1. A major citywide push, designated as D-Day, is scheduled for Saturday, August 22, when all 483 Basic Health Units in the capital will open their doors to administer shots.
Health officials explained that the campaign was launched following the identification of infection chains linked to imported cases of the virus. The initiative aims to raise overall vaccination coverage, update patient immunization records, and eliminate the risk of measles becoming re-established in the country. Measles is a highly contagious respiratory virus that causes fever and body rashes, but can be effectively controlled through widespread vaccination.
As part of the response, clinics are providing an early shot known as dose zero for infants aged six months to 11 months. Since June 29, a total of 21,709 infants in this age bracket have received the preliminary shot. The Municipal Health Secretariat emphasized that dose zero provides early protection but does not replace the standard MMR vaccine doses required at 12 months and 15 months under Brazil's National Vaccination Calendar. The MMR vaccine protects against measles, mumps, and rubella.
Rising case counts in São Paulo state
The public health surge comes as health authorities track a cluster of viral transmissions across the region. Municipal health data shows that São Paulo capital has recorded 20 confirmed measles cases in 2026. Health workers are currently investigating another 207 suspected cases, while 203 potential cases have been ruled out. No deaths from the disease have been reported in the city.
Across the wider state of São Paulo, confirmed cases rose to 23, according to the State Health Secretariat of São Paulo. Earlier in the week, on Monday, August 4, officials had logged 16 cases distributed among infants, children, and adults across the capital and the neighbouring industrial municipalities of São Bernardo do Campo and Guarulhos.
State health officials said two of the 23 confirmed cases were directly imported from outside the region, while the remaining 21 cases are epidemiologically linked to importation. Investigators have not yet pinpointed the exact source of infection for the secondary cluster.
The current outbreak marks an increase from 2025, when the state recorded just two imported cases of measles. Last year, the city of São Paulo maintained high protection levels, achieving 92.09 percent coverage for the first dose of the MMR vaccine and 91.88 percent coverage for the second dose.
