Boosting Dose of Pfizer-BioNtech mRNA Vaccine Against SARS-CoV-2 Does Not Affect Reproductive Outcomes in In-Vitro Fertilization Patients: A Cohort Study.

Background: Since the introduction of anti-COVID-19 mRNA vaccination, few studies have shown that reproductive outcomes in artificial reproductive technology (ART) treatments are not impaired, after receiving the two-dose regimen. Our aim was to investigate whether a boosting dose of the Pfizer-BioNtech mRNA vaccine affects reproductive outcomes in ART patients. Materials and Methods: This is a prospective observational study, including 157 consecutive in-vitro fertilization (IVF) cycles between October 1, 2021, and November 24, 2021, in a single university affiliated IVF unit. We included female patients going through an ART procedure and male partners in cases of utilization of a fresh sperm sample. The study population was divided into four groups according to exposure status: vaccinated and boosted patients (three total doses of Pfizer-BioNtech mRNA vaccine), patients who were vaccinated without the booster dose (one or two vaccine doses), PCR-confirmed convalescent COVID-19 patients, and unvaccinated nonconvalescent patients. Main outcome measure was clinical pregnancy rate. Results: In total, 99 (63%) female patients were vaccinated three times, 24 (15.3%) were vaccinated without the booster dose, 21 (13.4%) were convalescent, and 13 were (8.3%) unexposed. Although age differed between study groups, vaccination exposure status did not affect treatment outcome: clinical pregnancy rates, maximal estradiol levels, and number of oocytes retrieved did not differ significantly between study groups (p = 0.78, 0.50, and 0.97, respectively). Vaccinated patients who received a boosting vaccine dose were treated within 43.3 ± 30.9 days after receiving the last dose, whereas vaccinated, nonboosted, or convalescent patients were treated 168.7 ± 53 and 209.6 ± 85.1 days after their last exposure, respectively. We stratified the male cohort according to boosting vaccine dose status. Sperm concentration and motility did not differ significantly after boosting (p = 0.49 and 0.49, respectively). Conclusions: Our results provide further reassurance that IVF outcomes are not affected by the anti-SARS-CoV-2 Pfizer-BioNtech mRNA vaccine, in particular the three-dose regimen.

Boosting maternal and neonatal anti-SARS-CoV-2 humoral immunity using a third mRNA vaccine dose.

BACKGROUND: To minimize COVID-19 pandemic burden and spread, 3-dose vaccination campaigns commenced worldwide. Since patients who are pregnant are at increased risk for severe disease, they were recently included in that policy, despite the lack of available evidence regarding the impact of a third boosting dose during pregnancy, underscoring the urgent need for relevant data. We aimed to characterize the effect of the third boosting dose of mRNA Pfizer BNT162b2 vaccine in pregnancy. METHODS: We performed a prospective cohort study of anti-SARS-CoV-2 antibody titers (n = 213) upon delivery in maternal and cord blood of naive fully vaccinated parturients who received a third dose (n = 86) as compared with 2-dose recipients (n = 127). RESULTS: We found a robust surge in maternal and cord blood levels of anti-SARS-CoV-2 titers at the time of delivery, when comparing pregnancies in which the mother received a third boosting dose with 2-dose recipients. The effect of the third boosting dose remained significant when controlling for the trimester of last exposure, suggesting additive immunity extends beyond that obtained after the second dose. Milder side effects were reported following the third dose, as compared with the second vaccine dose, among the fully vaccinated group. CONCLUSION: The third boosting dose of mRNA Pfizer BNT162b2 vaccine augmented maternal and neonatal immunity with mild side effects. These data provide evidence to bolster clinical and public health guidance, reassure patients, and increase vaccine uptake among patients who are pregnant. FUNDING: Israel Science Foundation KillCorona grant 3777/19; Research grant from the "Ofek" Program of the Hadassah Medical Center.

Boosting maternal and neonatal humoral immunity following SARS-CoV-2 infection using a single messenger RNA vaccine dose.

BACKGROUND: Post-COVID-19 vaccine boosting is a potent tool in the ongoing pandemic. Relevant data regarding this approach during pregnancy are lacking, which affects vaccination policy guidance, public acceptance, and vaccine uptake during pregnancy. We aimed to investigate the dynamics of anti-SARS-CoV-2 antibody levels following SARS-CoV-2 infection during pregnancy and to characterize the effect of a single postinfection vaccine booster dose on the anti-SARS-CoV-2 antibody levels in parturients in comparison with the levels in naïve vaccinated and convalescent, nonboosted parturients. STUDY DESIGN: Serum samples prospectively collected from parturients and umbilical cords at delivery at our university-affiliated urban medical center in Jerusalem, Israel, from May to October 2021, were selected and analyzed in a case-control manner. Study groups comprised the following participants: a consecutive sample of parturients with a polymerase chain reaction-confirmed history of COVID-19 during any stage of pregnancy; and comparison groups selected according to time of exposure comprising (1) convalescent, nonboosted parturients with polymerase chain reaction-confirmed COVID-19; (2) convalescent parturients with polymerase chain reaction-confirmed COVID-19 who received a single booster dose of the BNT162b2 messenger RNA vaccine; and (3) infection-naïve, fully vaccinated parturients who received 2 doses of the BNT162b2 messenger RNA vaccine. Outcomes that were determined included maternal and umbilical cord blood anti-SARS-CoV-2 antibody levels detected at delivery, the reported side effects, and pregnancy outcomes. RESULTS: A total of 228 parturients aged 18 to 45 years were included. Of those, samples from 64 were studied to characterize the titer dynamics following COVID-19 at all stages of pregnancy. The boosting effect was determined by comparing (1) convalescent (n=54), (2) boosted convalescent (n=60), and (3) naïve, fully vaccinated (n=114) parturients. Anti-SARS-CoV-2 antibody levels detected on delivery showed a gradual and significant decline over time from infection to delivery (r=0.4371; P=.0003). Of the gravidae infected during the first trimester, 34.6% (9/26) tested negative at delivery, compared with 9.1% (3/33) of those infected during the second trimester (P=.023). Significantly higher anti-SARS-CoV-2 antibody levels were observed among boosted convalescent than among nonboosted convalescent (17.6-fold; P<.001) and naïve vaccinated parturients (3.2-fold; P<.001). Similar patterns were observed in umbilical cord blood. Side effects in convalescent gravidae resembled those in previous reports of mild symptoms following COVID-19 vaccination during pregnancy. CONCLUSION: Postinfection maternal humoral immunity wanes during pregnancy, leading to low or undetectable protective titers for a marked proportion of patients. A single boosting dose of the BNT162b2 messenger RNA vaccine induced a robust increase in protective titers for both the mother and newborn with moderate reported side effects.