Early Adverse Events and Immune Response Following Second and Third COVID-19 Vaccination in Pregnancy

Abstract

(1) Background: The adverse-effect profile and short-term obstetric and neonatal outcomes among pregnant women who were vaccinated with the BNT162b2 vaccine at any stage of pregnancy do not indicate any safety concerns. The vaccine is effective in generating a humoral immune response in pregnant women. (2) Objective: To determine the vaccine-induced immunity and adverse events associated with the third (booster) dose of the BNT162b2 vaccine compared to the first and second dose of the vaccine among pregnant women. (3) Study design: A prospective cohort study in a tertiary referral center comparing pregnant women who were vaccinated by the first and second dose of the BNT162b2 (Pfizer/BioNTech) vaccine to pregnant women vaccinated by a third (booster) dose, between January and November 2021. A digital questionnaire regarding adverse events was filled by both groups 2–4 weeks after vaccination. Blood samples were collected and tested for SARS-COV-2 IgG antibodies 28–32 days after the administration of the second or third BNT162b2 dose. (4) Results: Seventy-eight pregnant women who received the first and second doses of the vaccine were compared to eighty-four pregnant women who received the third dose of the vaccine. In terms of adverse events following vaccination, local rash/pain/swelling (93.6% vs. 72.6%, p < 0.001) was significantly less common after the third vaccination compared to after the second vaccination. Other adverse events, including early obstetric complications, did not differ between the two groups. SARS-CoV-2 IgG serum levels 28–32 days after the vaccination were significantly higher after the third vaccination compared to the second vaccination (1333.75 vs. 2177.93, respectively, p < 0.001). (5) Conclusion: This study confirms the safety regarding early adverse events and immunogenicity, and the lack of early obstetric complications of the BNT162b2 second- and third-dose vaccine in pregnant women. The third (booster) dose is effective in generating a stronger humoral immune response in pregnant women compared with the second dose.

Maternal and Neonatal Immune Responses Following COVID-19 Infection and Vaccinations in Pregnancy

“…Our results coincide with previous reports showing antibody levels among pregnant women to be significantly higher after the third dose compared to the second dose [19,20,26] and significantly higher after the second dose compared to recovered women [9,12,27]. Similar patterns were demonstrated in neonatal antibody levels [9,12,19,20,27].…”

“…Published reports have confirmed the enhanced humoral response of almost all patients to the third dose, especially in populations with a low humoral response or waning immunity after the first and second doses [28][29][30]. In pregnant women and their neonates, recent studies have shown that similar to the first and second doses of the BNT162b2 vaccine, the third dose is successful in generating a remarkable humoral immune response of SARS-CoV-2 IgG, as well as being safe [18][19][20]. Moreover, a Norwegian population-based cohort study suggested there was a lower risk of a positive test for SARS-CoV-2 during the first 4 months of life among infants born to mothers who were vaccinated during pregnancy [31].…”

“…Recent studies have shown that, similar to the first and second doses of the BNT162b2 vaccine, the third dose is also safe in pregnancy and effective in generating a significant humoral immune response of SARS-CoV-2 IgG in pregnant women and their fetuses. [18][19][20][21].…”

Cord blood antibodies following BBIBP‐CorV (Sinopharm) vaccination during pregnancy

“…Pregnancy would increase the susceptibility to severe infection and death from COVID‐19 24 . Consistent with our results, the prior investigations strongly recommended that vaccination should be performed during pregnancy to provide maternal and infant protection against COVID‐19 disease 22,25,26 . Therefore, it seems crucial to determine the optimum time of vaccination for pregnant women, to reach the highest level of maternal and neonatal immunization.…”

“… 24 Consistent with our results, the prior investigations strongly recommended that vaccination should be performed during pregnancy to provide maternal and infant protection against COVID‐19 disease. 22 , 25 , 26 Therefore, it seems crucial to determine the optimum time of vaccination for pregnant women, to reach the highest level of maternal and neonatal immunization. Rottenstreich et al presented that maternal vaccination early in the third trimester resulted in a greater maternal‐to‐neonatal transfer ratio of SARS‐CoV‐2 antibody and a higher neonatal immunoglobulin concentration, compared with vaccination in the late third trimester.…”