The child arrives already defended.
RSV causes 43.7k severe respiratory cases annually in Brazil, with 82% affecting children under 2 years old, responsible for 75% of bronchiolitis cases. Pfizer's Abrysvo vaccine is administered as single dose to pregnant women from week 28, with potential to prevent approximately 28,000 hospitalizations yearly.
- 43,700 cases of severe RSV respiratory syndrome in Brazil through late November 2024, 82% in children under 2
- Abrysvo vaccine administered as single dose to pregnant women from week 28 of pregnancy
- Vaccine projected to prevent approximately 28,000 hospitalizations annually
- Technology transfer agreement with Butantan Institute enables domestic vaccine manufacturing
Brazil's Health Ministry begins distributing Abrysvo vaccine against respiratory syncytial virus (RSV) through SUS, targeting pregnant women from week 28 of pregnancy to protect newborns from bronchiolitis.
Brazil's Health Ministry has begun distributing the Abrysvo vaccine, a new tool against respiratory syncytial virus, or RSV—a pathogen that has quietly become one of the most consequential threats to infants in the country. The vaccine is arriving in public health clinics now, with doses flowing to states and municipalities as they arrive, ready for immediate deployment at local health posts.
The virus itself is unremarkable in name but devastating in effect. RSV is the leading cause of bronchiolitis, an acute inflammation of the small airways in the lungs that can turn a respiratory infection into a medical emergency requiring hospitalization. For children under two years old, it accounts for roughly three-quarters of all bronchiolitis cases and up to 40 percent of pneumonias. The numbers are stark: through late November this year, Brazil recorded 43,700 cases of severe acute respiratory syndrome caused by RSV, and 82 percent of them occurred in children younger than two.
The vaccine itself—developed by Pfizer and now incorporated into Brazil's National Immunization Program—takes an unusual approach. Rather than vaccinating infants directly, it targets pregnant women. A single dose, administered from the 28th week of pregnancy onward, primes the mother's immune system to pass protective antibodies to her baby before birth. The child arrives already defended. The logic is elegant: newborns cannot receive most vaccines in their first weeks of life, but they can inherit immunity from their mothers.
The arrival of Abrysvo in the public system carries weight beyond the clinic walls. According to projections from Fiocruz, the vaccine could prevent approximately 28,000 hospitalizations annually—a figure that translates not just to lives made safer but to beds freed, resources redirected, and families spared the ordeal of watching an infant struggle to breathe. Tatiana Portella, a researcher with Fiocruz's scientific computing program and the Infogripe surveillance system, emphasized that pregnant women from the 28th week onward should receive the vaccine, and that the recommendation applies to each pregnancy.
The vaccine has already been available in Brazil's private health system since September 2024, where it serves not only pregnant women but also elderly people—another population vulnerable to severe RSV infection. Abrysvo remains the only vaccine approved in Brazil for all three of the most at-risk groups: infants, older adults, and people with chronic conditions. But the public system's adoption marks a shift toward equity, ensuring access is not limited to those who can pay.
Behind the distribution lies a technology transfer agreement between Pfizer and the Butantan Institute, a state research institution in São Paulo. The arrangement commits Pfizer to help Brazil manufacture the vaccine domestically, a move that signals confidence in the vaccine's role in the country's immunization future and reduces dependence on imported doses. Adriana Ribeiro, Pfizer's medical director in Brazil, framed the moment as one of institutional pride—the chance to help protect families from a virus that has shaped pediatric medicine and public health for decades.
As 2026 approaches, epidemiologists are watching to see whether the vaccine's introduction will bend the curve of RSV hospitalizations downward. The surveillance data will tell the story. For now, the doses are moving through the system, and pregnant women are being asked to take a single step that protects the next generation before it even takes its first breath.
Citas Notables
The vaccine has the potential to prevent about 28,000 hospitalizations per year, which represents a major benefit for the health system as a whole.— Adriana Ribeiro, medical director of Pfizer Brasil
It is fundamental that pregnant women from the 28th week of pregnancy vaccinate themselves against RSV, ensuring their children are protected.— Tatiana Portella, researcher at Fiocruz's Infogripe surveillance program
La Conversación del Hearth Otra perspectiva de la historia
Why target pregnant women instead of vaccinating babies directly after birth?
Newborns can't receive most vaccines safely in their first weeks. But they can inherit antibodies from their mothers if the mother is vaccinated during pregnancy. It's nature's relay—the mother passes immunity to the child before birth, protecting the baby from day one.
How serious is RSV really? It sounds like a cold.
It can be. But in infants under two, it's the leading cause of bronchiolitis—a condition that inflames the small airways in the lungs and can make breathing so difficult the child needs hospitalization. Seventy-five percent of bronchiolitis cases in that age group are RSV. It's not always severe, but when it is, it's serious.
What does preventing 28,000 hospitalizations actually mean for a country?
It means 28,000 families who don't have to spend nights in a hospital watching their infant struggle. It means beds available for other patients, resources stretched less thin, and a public health system that can breathe a little easier.
Why is the Butantan agreement important?
Because it means Brazil won't be dependent on imported doses forever. Domestic manufacturing makes the vaccine sustainable and affordable long-term. It's the difference between borrowing a tool and owning the factory that makes it.
Who gets the vaccine right now?
Pregnant women from the 28th week onward, through the public system. It's been available in private clinics since last September for pregnant women, elderly people, and adults with chronic conditions. The public rollout is newer and broader in reach.
What happens if a woman is pregnant again after getting vaccinated?
She gets vaccinated again. The recommendation is one dose per pregnancy. Each pregnancy is a new opportunity to protect that specific child.