- Receipt of the 2009 H1N1 vaccination during pregnancy is not associated with any serious pediatric complications.
Why this matters
- All pregnant women are advised to get immunized against influenza to prevent maternal complications and provide passive immunity to infants.
- Uptake of influenza vaccination during pregnancy has been low because of perceived safety concerns.
- 30% of cohort received vaccination.
- No association was identified between vaccination and pediatric infections, neoplasms, sensory disorders, health care use, pediatric complex chronic conditions, or mortality up to age 5 years.
- A small increase in pediatric asthma risk was seen: adjusted HR, 1.05 (95% CI, 1.02-1.09).
- Also, a small decrease in gastrointestinal infections: adjusted incidence rate ratio, 0.94 (95% CI, 0.91-0.98).
- Retrospective cohort study.
- Cohort identified from a population-based birth registry linked with a Canadian health administrative database (n=104,249).
- Exposure of interest was receipt of the 2009 H1N1 influenza vaccination during pregnancy (n=31,295).
- Children who were in utero during maternal vaccination were followed to age 5 years.
- Funding: the Canadian Institutes of Health Research and by ICES, which is funded by an annual grant from the Ontario Ministry of Health and Long term Care.
- Cohort followed only 5 years.
- Vaccinations change yearly.