Early exposure to yellow fever vaccine during pregnancy

Abstract

Summaryobjective To investigate the association of Yellow Fever Vaccination (YFV) during pregnancy with the presence of structural defect in exposed babies.methods An observed/expected frequencies study, before and after the vaccination campaign against YF was designed. 304 babies exposed to YFV during the prenatal period underwent dysmorphological examinations. The expected frequencies of malformations were obtained from a reference population of 10 691 births occurred in the period immediately prior to the vaccination campaign and born in the same region. These frequencies were evaluated using Poisson distribution model.results The major malformation rate found in this study was 3.3% (CI 1.7-6.3%). Minor dysmorphisms, especially naevus, were significantly more frequent (P < 0.001) than in the reference population.conclusions The data here presented provide no indication that immunization with YFV early in pregnancy increases the risk of major malformations. However, the association found between YFV during pregnancy and minor dysmorphisms, especially pigmented naevus, seems to be a bias of evaluation. We suggest, nevertheless, that a reproductive risk hypothesis regarding minor dysmorphisms should be considered in future studies involving YFV.

Congenital anomalies: Case definition and guidelines for data collection, analysis, and presentation of immunization safety data

“…The risks of adverse outcome of pregnancy and childbirth appear to be similar to those in the general population [49], [50].…”

Efficacy and Duration of Immunity after Yellow Fever Vaccination: Systematic Review on the Need for a Booster Every 10 Years

“…32,72,73 Fortunately, two studies provided data on seroconversion rates. The results varied, depending on the trimester in which vaccine was administered.…”

Emerging Role of Zika Virus in Adverse Fetal and Neonatal Outcomes

“…Transmission via breastfeeding has been recorded for the yellow fever vaccine virus (attenuated 17DD substrain; approved by WHO) (244). Several studies have investigated the effect of yellow fever vaccination during early pregnancy (245)(246)(247). None of these studies indicated that in utero exposure to yellow fever vaccine resulted in an increased risk of major malformations.…”