There are limited studies of the long-term safety in infants for vaccines administered during pregnancy.
We evaluate whether maternal receipt of influenza and Tdap vaccines increases the risk of infant hospitalization or death in the first 6 months of life.
We included singleton, live birth pregnancies in the Vaccine Safety Datalink between 2004 and 2014.
We found no association between infant hospitalization and maternal influenza or Tdap vaccinations. We found no association between infant mortality and maternal influenza or Tdap vaccinations.
We found no association between vaccination during pregnancy and risk of infant hospitalization or death in the first 6 months of life.
These findings support the safety of current recommendations for influenza and Tdap vaccination during pregnancy.
The Advisory Committee on Immunization Practices currently recommends 2 vaccines to be given during each pregnancy; influenza vaccine has been recommended at any time during pregnancy since 2004 to prevent maternal influenza disease and complications1 and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine has been recommended during each pregnancy since 2012, with a preference for administration between 27 and 36 weeks’ gestation…
In 2014, the US pertussis case rate in infants <6 months of age was 169 per 100 000 infants.
Furthermore, there were 8 deaths in infants <3 months of age and 1 death in infants 3 to 11 months of age out of 13 total deaths from pertussis in all age groups in 2014.*
For the 2013–2014 influenza season, there were 96 laboratory-confirmed, influenza-associated** pediatric deaths…
[We] excluded infants of multiple gestation pregnancies, infants born before 34 weeks’ gestation, and infants with major birth defects because these infants are at a higher risk of hospitalization and death. Furthermore, we excluded all infants who died during their delivery hospitalization because cause of death in these infants is often a perinatal complication (such as placental abruption) that would likely be unrelated to maternal vaccination.
Additionally, infants who die during the birth hospitalization may be less likely to be enrolled in the VSD and captured in our data.***