Rheumatologic diseases commonly affect women of childbearing age.(1,2) There is currently limited data available regarding the safety of vaccinations in infants after in utero exposure to biologics.
To determine the vaccination decisions of mothers with rheumatologic diseases exposed to biologics during pregnancy and the incidence of serious neonatal infection after third trimester exposure.
All Australian women with inflammatory arthritis, exposed to biologics during the preconception, antenatal and / or postpartum periods, were invited to participate in the Pregnancy Exposed to Biological (PEB) study from May 2009 – May 2018. Recruitment was via direct invitation from patients treating rheumatologists, community groups, and via social media. Following self-referral to the study, retrospective data was collected, including biological exposure, vaccination history and the incidence of serious neonatal infections, defined as infection requiring hospitalisation.
Preliminary data is available regarding 35 offspring from 28 mothers. All 35 offspring were vaccinated, however, one infant did not commence the vaccination schedule until age 2, due to maternal preference. 27 received vaccinations in accordance with the Australian National Immunisation Program Schedule.
13 infants were exposed to a tumour necrosis factor inhibitor (TNFi) or targeted synthetic inhibitor (tsDMARD) during the third trimester. Of these, 4 had Rotavirus vaccine delayed from 2 to 4 months and 1 infant until 6 months. 1 infant did not receive the Rotavirus vaccine at 2 months due to exposure to a TNFi while breastfeeding. There were no incidences of serious neonatal infections.
Current guidelines recommend deferring live vaccines, such as rotavirus, until after 6 months if exposed to a biologic in the third trimester.(2-5) Compliance with these recommendations were only observed in one infant in our study. One infant received delayed Rotavirus vaccination due to concern about TNFi exposure during breastfeeding; this is not in keeping with current guidelines. Of the 12 infants exposed to a biologic during the third trimester who did not delay live vaccination until after 6 months, there were no incidents of serious neonatal infections, in keeping with the findings of current published case series.