Neonatal outcomes after influenza immunization during pregnancy: a randomized controlled trial

Experience and challenges on influenza and pertussis vaccination in pregnant women

“…23 , 24 In addition, an earlier RCT from Bangladesh, reported that the weight of newborns born during influenza season to women who received IIV during pregnancy was 200 gram higher than those born to mothers vaccinated with pneumococcal polysaccharide vaccine. 25 These conflicting data from the RCTs, suggest a marginal effect of seasonal IIV on birth weight, but no reduction in the rate of preterm birth. A caveat of these studies include there being some mismatch between the vaccine and circulating wild-type influenza strains, although protection was shown against influenza-confirmed illness in the mothers and their infants.…”

Review on the effects of influenza vaccination during pregnancy on preterm births

“…19,20 Another attractive bonus of maternal immunization would be to protect the fetus from the unintended consequences of infection described above. 21 However, clear evidence that immunization during pregnancy may improve birth outcomes is still lacking and inconsistent observations have been reported.…”

“…20,21 The large majority of the other studies investigating the impact of maternal influenza vaccination during pregnancy on preterm deliveries have been observational. The objective of these observational studies was to evaluate the safety of antenatal vaccination, exploring whether there was an association between vaccination and birth outcomes either prospectively or retrospectively using population-based perinatal databases.…”

Maternal immunization

“…[35][36][37][38] In fact, maternal immunization may reduce rates of preterm birth and suboptimal growth among infants of vaccinated mothers. 39,40 In a landmark randomized controlled trial published in 2008, Zaman and colleagues demonstrated that maternal influenza vaccination confers neonatal protection against influenza, 41 presumably due to transplacental passage of maternal IgG antibody to the fetus. 42 Maternal influenza vaccination has also been associated with reduced rates of influenza-related hospitalization of infants less than 6 mo of age.…”

“…67,87 Reassuringly, patients' focus on potential vaccine harm comes at a time of growing data about the benefits and safety of maternal vaccination for babies. 32,33,35,[39][40][41] Emphasizing the benefits of maternal immunization, including its safety and absence of fetal harm, should help decrease the perceived cost of maternal immunizations.…”