Most new parents dread that first bad cough or wheeze in a tiny baby.
Winter is the season when respiratory infections circulate hardest, and the youngest infants are the ones who end up in the hospital most often.
One virus is behind a large share of those admissions.
A report from the European Centre for Disease Prevention and Control was published on October 28, 2026.
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It finds that immunizing every newborn against respiratory syncytial virus (RSV) could prevent more than half of RSV hospitalizations in the youngest babies.
RSV is the leading cause of hospitalization among US infants, and babies in their first few months are at highest risk.
There are now two ways to protect a newborn, and the ECDC assessment looked at both.
What the ECDC projections show
The agency's models looked at two strategies. One is giving every newborn a long-acting antibody shot right after birth.
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The other is vaccinating the mother late in pregnancy so protection passes to the baby.
If 90 percent of newborns received the antibody at birth, the models project 61 percent of RSV hospitalizations in the first two months of life could be prevented.
Universal maternal vaccination would prevent an estimated 52 percent in the same window.
"Protecting infants from RSV in the first months of their life is particularly important, and we have a tool to do just that," said Bruno Ciancio, head of unit at ECDC, in the agency's statement.
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How to protect a newborn this season?
In the US, the Centers for Disease Control and Prevention already recommends that every baby be protected one of two ways.
Pregnant women can get Pfizer's Abrysvo vaccine between 32 and 36 weeks of pregnancy, which passes antibodies to the baby.
Babies born to mothers who did not get the vaccine should receive a long-acting antibody shot.
Two are approved: nirsevimab and clesrovimab. The shot should be given within a week of birth if the baby is born during RSV season, roughly October through March.
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The maternal vaccine Abrysvo has been shown to protect newborns against severe RSV in the first months of life. Infant antibody protection lasts about five months, enough to cover a typical RSV season.
US data suggest the approach is already working.
According to the CDC's Morbidity and Mortality Weekly Report, RSV hospitalization rates for infants aged 0 to 7 months fell during the 2024-25 season.
They were 43 percent lower than in the pre-prevention years of 2018-20.
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Warning signs that need medical attention
RSV usually looks like a bad cold, and in most babies it stays that way. But in very young infants it can quickly turn into a serious lower respiratory tract infection.
Signs to watch for include fast or labored breathing, a drawn-in chest when the baby breathes, poor feeding, or a bluish tinge to the lips.
Those are reasons to seek medical attention promptly.
For a baby born this fall in the US, the current CDC advice is simple. If the mother received Abrysvo during pregnancy, the baby is already protected.
Otherwise, parents should ask their pediatrician about a nirsevimab or clesrovimab shot in the baby's first week.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.