tetano
Editor, Senior Moderator
Hum Vaccin Immunother
. 2025 Dec;21(1):2585595.
doi: 10.1080/21645515.2025.2585595. Epub 2025 Nov 18. Population-based cohort study assessing the effectiveness of maternal BNT162b2/mRNA-1273 vaccination against infant coronavirus disease 2019 outcomes during Omicron predominance: The VENUS study
Chieko Ishiguro[SUP] 1 [/SUP], Wataru Mimura[SUP] 1 [/SUP], Futoshi Oda[SUP] 2 [/SUP], Megumi Maeda[SUP] 2 [/SUP], Haruhisa Fukuda[SUP] 2 [/SUP]
Affiliations
Maternal Coronavirus disease 2019 (COVID-19) vaccination during pregnancy enables transplacental antibody transfer; however, data on clinical effectiveness in infants are limited. We evaluated the BNT162b2 and mRNA-1273 vaccine effectiveness (VE) of maternal second and third doses against COVID-19 in infants during Omicron predominance. This population-based cohort study in a Japanese municipality included infants born between January and August 2022. Maternal vaccination status at delivery was classified as unvaccinated, second dose before pregnancy, second dose during pregnancy, or third dose during pregnancy. Follow-up for COVID-19 outcomes - primary (infection) and secondary (hospitalization) - began at delivery and ended at the infant's 6-month birthday or September 25, 2022, whichever came first. Adjusted hazard ratios (HRs) were estimated using Cox regression, comparing the second dose during pregnancy with no vaccination and comparing the third dose during pregnancy with the second dose before pregnancy. VE was calculated as (1-adjusted HR) × 100%). We identified 613 infants: 234, 72, 181, and 126 whose mothers were unvaccinated, received the second dose before pregnancy, received the second dose during pregnancy, and received the third dose during pregnancy, respectively. Fifty-one infants developed an infection. Three hospitalizations occurred only among infants in the unvaccinated and second-dose-before-pregnancy groups. VE of the second and third doses against infection was 1% (95% confidence interval [CI]:-87% to 47%) and 71% (95% CI:-7% to 92%), respectively. This study indicates that a third dose during pregnancy may be effective in protecting infants from COVID-19 infection during Omicron predominance, while a second dose limited effectiveness.
Keywords: COVID-19; effectiveness; infants; pregnancy; vaccination.
. 2025 Dec;21(1):2585595.
doi: 10.1080/21645515.2025.2585595. Epub 2025 Nov 18. Population-based cohort study assessing the effectiveness of maternal BNT162b2/mRNA-1273 vaccination against infant coronavirus disease 2019 outcomes during Omicron predominance: The VENUS study
Chieko Ishiguro[SUP] 1 [/SUP], Wataru Mimura[SUP] 1 [/SUP], Futoshi Oda[SUP] 2 [/SUP], Megumi Maeda[SUP] 2 [/SUP], Haruhisa Fukuda[SUP] 2 [/SUP]
Affiliations
- PMID: 41253307
- PMCID: PMC12629327
- DOI: 10.1080/21645515.2025.2585595
Maternal Coronavirus disease 2019 (COVID-19) vaccination during pregnancy enables transplacental antibody transfer; however, data on clinical effectiveness in infants are limited. We evaluated the BNT162b2 and mRNA-1273 vaccine effectiveness (VE) of maternal second and third doses against COVID-19 in infants during Omicron predominance. This population-based cohort study in a Japanese municipality included infants born between January and August 2022. Maternal vaccination status at delivery was classified as unvaccinated, second dose before pregnancy, second dose during pregnancy, or third dose during pregnancy. Follow-up for COVID-19 outcomes - primary (infection) and secondary (hospitalization) - began at delivery and ended at the infant's 6-month birthday or September 25, 2022, whichever came first. Adjusted hazard ratios (HRs) were estimated using Cox regression, comparing the second dose during pregnancy with no vaccination and comparing the third dose during pregnancy with the second dose before pregnancy. VE was calculated as (1-adjusted HR) × 100%). We identified 613 infants: 234, 72, 181, and 126 whose mothers were unvaccinated, received the second dose before pregnancy, received the second dose during pregnancy, and received the third dose during pregnancy, respectively. Fifty-one infants developed an infection. Three hospitalizations occurred only among infants in the unvaccinated and second-dose-before-pregnancy groups. VE of the second and third doses against infection was 1% (95% confidence interval [CI]:-87% to 47%) and 71% (95% CI:-7% to 92%), respectively. This study indicates that a third dose during pregnancy may be effective in protecting infants from COVID-19 infection during Omicron predominance, while a second dose limited effectiveness.
Keywords: COVID-19; effectiveness; infants; pregnancy; vaccination.