Flu and whooping-cough vaccines in pregnancy linked to fewer hospital visits in babies
A large study finds that babies born to vaccinated mothers are much less likely to be admitted to hospital or taken to emergency care with influenza or pertussis in their first six months of life.
- 16 January 2026
- 4 min read
- by Linda Geddes
At a glance
- While flu and whooping cough vaccines are recommended during pregnancy, large population-based studies examining their real-world impact have been limited.
- A new study published in JAMA Network Open analysed health records from hundreds of thousands of pregnancies in northern Italy and found that babies born to vaccinated mothers were far less likely to need hospital or emergency care for influenza or pertussis in their first six months of life.
- The findings strengthen support for current vaccination guidelines in pregnancy and suggest that improving vaccine uptake could prevent serious illness in infants too young to be vaccinated themselves.
For the first months of life, babies rely on their mothers – and their immune systems – for protection. A large Italian study now shows that when pregnant people receive flu or whooping cough vaccines, their babies are far less likely to end up in hospital with these infections.
“These findings suggest support for the current recommendations for administering the Tdap [tetanus, diphtheria and pertussis] and influenza vaccines during pregnancy and underline the urgent need to implement strategies to improve their acceptance,” the authors said.
How well do maternal flu and whooping cough vaccines protect newborn babies?
Influenza and pertussis (whooping cough) cause serious illness and death around the world, especially in pregnant people and very young babies, who are more likely to develop severe complications.
Because babies under six months old cannot receive the flu vaccine, and those under two months old are too young to receive the combined vaccine against diphtheria, tetanus and pertussis (Tdap), one way to protect them is to vaccinate their mothers during pregnancy.
Antibodies passed from mother to baby then provide them with enough protection to see them through until they’re old enough to be vaccinated themselves.
Babies whose mothers received the influenza vaccine during pregnancy were about 70% less likely to be hospitalised for influenza during their first six months of life.
Previous studies have suggested that flu vaccination during pregnancy can reduce flu infections in infants by about 50% to 80%, while vaccination against pertussis during pregnancy has been linked to a 70% to 90% reduction in whooping cough in young babies.
However, because most of these studies have been limited in size or carried out in specific settings, further studies were needed to understand how well maternal vaccination works in everyday healthcare systems.
To investigate, Gabriella Morabito at the University of Milano-Bicocca in Milan, Italy, and colleagues analysed health records from 339,021 pregnancies in the Lombardy region of northern Italy between 2018 and 2022 – including 84,348 mother-infant pairs in the influenza analysis and 171,141 pairs in the Tdap analysis.
For both vaccines, babies born to vaccinated mothers were compared with similar babies whose mothers had not been vaccinated.
The research, published in JAMA Network Open, found that babies whose mothers received the influenza vaccine during pregnancy were about 70% less likely to be hospitalised for influenza during their first six months of life. For those born to mothers who had the Tdap vaccine, the risk of pertussis-related hospital visits was cut by nearly 89%.
“Our results align with studies conducted in the US and Australia that have documented a protective association between maternal vaccination and severe diseases in young infants,” the researchers said.
They added that a key strength of the study was its use of routine healthcare records alongside the CeDAP birth registry, which records all births in Lombardy, allowing analysis of a large, population-wide cohort.
How common are flu and whooping cough vaccines in pregnancy?
Current Italian health guidelines recommend that pregnant people receive both flu and whooping cough vaccines during pregnancy, with the whooping cough shot usually offered during the third trimester of pregnancy and the flu shot at any time. The World Health Organization also supports their use during pregnancy.
Yet, despite strong evidence that they are safe and effective, uptake in Italy remains low. During the study period, only 6.4% of pregnant people in Lombardy received the influenza vaccine, while 41% received the Tdap vaccine.
The researchers said they hoped their findings could help strengthen efforts to improve vaccine confidence and coverage, ultimately reducing serious illness among young infants.
