tetano
Editor, Senior Moderator
Open Forum Infect Dis
. 2022 Oct 19;9(11)
fac552.
doi: 10.1093/ofid/ofac552. eCollection 2022 Nov.
Effectiveness of Influenza Vaccination of Pregnant Women for Prevention of Maternal and Early Infant Influenza-Associated Hospitalizations in South Africa: A Prospective Test-Negative Study
Marta C Nunes[SUP] 1 2 [/SUP], Sibongile Walaza[SUP] 3 4 [/SUP], Susan Meiring[SUP] 3 4 5 [/SUP], Heather J Zar[SUP] 6 [/SUP], Gary Reubenson[SUP] 7 [/SUP], Meredith McMorrow[SUP] 8 [/SUP], Stefano Tempia[SUP] 4 8 [/SUP], Liza Rossi[SUP] 3 [/SUP], Raphaela Itzikowitz[SUP] 3 [/SUP], Kate Bishop[SUP] 3 [/SUP], Azwifarwi Mathunjwa[SUP] 3 [/SUP], Amy Wise[SUP] 9 [/SUP], Florette K Treurnicht[SUP] 3 [/SUP], Orienka Hellferscee[SUP] 3 4 [/SUP], Matt Laubscher[SUP] 1 2 [/SUP], Natali Serafin[SUP] 1 2 [/SUP], Clare L Cutland[SUP] 1 2 10 [/SUP], Shabir A Madhi[SUP] 1 2 10 [/SUP], Cheryl Cohen[SUP] 3 4 [/SUP]
Affiliations
Abstract
Background: Influenza vaccination during pregnancy reduces influenza-associated illness in the women and their infants, but effectiveness estimates against influenza-associated hospitalization are limited and lacking from settings with high human immunodeficiency virus (HIV) infection prevalence. We assessed the effect of maternal vaccination in HIV-uninfected women and women with HIV in preventing influenza-associated hospitalizations in infants and the women.
Methods: During 2015-2018, influenza vaccination campaigns targeting pregnant women were augmented at selected antenatal clinics; these were coupled with prospective hospital-based surveillance for acute respiratory or febrile illness in infants aged <6 months and cardiorespiratory illness among pregnant or postpartum women. Vaccine effectiveness (VE) was assessed using a test-negative case-control study.
Results: Overall, 71 influenza-positive and 371 influenza-negative infants were included in the analysis; mothers of 26.8% of influenza-positive infants were vaccinated during pregnancy compared with 35.6% of influenza-negative infants, corresponding to an adjusted VE (aVE) of 29.0% (95% confidence interval [CI], -33.6% to 62.3%). When limited to vaccine-matched strains, aVE was 65.2% (95% CI, 11.7%-86.3%). For maternal hospitalizations, 56 influenza-positive and 345 influenza-negative women were included in the analysis, with 28.6% of influenza-positive women being vaccinated compared with 38.3% of influenza-negatives, for an aVE of 46.9% (95% CI, -2.8% to 72.5%). Analysis restricted to HIV-uninfected women resulted in 82.8% (95% CI, 40.7%-95.0%) aVE. No significant aVE (-32.5% [95% CI, -208.7% to 43.1%]) was detected among women with HIV.
Conclusions: Influenza vaccination during pregnancy prevented influenza-associated hospitalizations among young infants when infected with vaccine strains and among HIV-uninfected women.
Keywords: influenza; pregnancy; vaccine.
. 2022 Oct 19;9(11)
fac552.doi: 10.1093/ofid/ofac552. eCollection 2022 Nov.
Effectiveness of Influenza Vaccination of Pregnant Women for Prevention of Maternal and Early Infant Influenza-Associated Hospitalizations in South Africa: A Prospective Test-Negative Study
Marta C Nunes[SUP] 1 2 [/SUP], Sibongile Walaza[SUP] 3 4 [/SUP], Susan Meiring[SUP] 3 4 5 [/SUP], Heather J Zar[SUP] 6 [/SUP], Gary Reubenson[SUP] 7 [/SUP], Meredith McMorrow[SUP] 8 [/SUP], Stefano Tempia[SUP] 4 8 [/SUP], Liza Rossi[SUP] 3 [/SUP], Raphaela Itzikowitz[SUP] 3 [/SUP], Kate Bishop[SUP] 3 [/SUP], Azwifarwi Mathunjwa[SUP] 3 [/SUP], Amy Wise[SUP] 9 [/SUP], Florette K Treurnicht[SUP] 3 [/SUP], Orienka Hellferscee[SUP] 3 4 [/SUP], Matt Laubscher[SUP] 1 2 [/SUP], Natali Serafin[SUP] 1 2 [/SUP], Clare L Cutland[SUP] 1 2 10 [/SUP], Shabir A Madhi[SUP] 1 2 10 [/SUP], Cheryl Cohen[SUP] 3 4 [/SUP]
Affiliations
- PMID: 36447608
- PMCID: PMC9697604
- DOI: 10.1093/ofid/ofac552
Abstract
Background: Influenza vaccination during pregnancy reduces influenza-associated illness in the women and their infants, but effectiveness estimates against influenza-associated hospitalization are limited and lacking from settings with high human immunodeficiency virus (HIV) infection prevalence. We assessed the effect of maternal vaccination in HIV-uninfected women and women with HIV in preventing influenza-associated hospitalizations in infants and the women.
Methods: During 2015-2018, influenza vaccination campaigns targeting pregnant women were augmented at selected antenatal clinics; these were coupled with prospective hospital-based surveillance for acute respiratory or febrile illness in infants aged <6 months and cardiorespiratory illness among pregnant or postpartum women. Vaccine effectiveness (VE) was assessed using a test-negative case-control study.
Results: Overall, 71 influenza-positive and 371 influenza-negative infants were included in the analysis; mothers of 26.8% of influenza-positive infants were vaccinated during pregnancy compared with 35.6% of influenza-negative infants, corresponding to an adjusted VE (aVE) of 29.0% (95% confidence interval [CI], -33.6% to 62.3%). When limited to vaccine-matched strains, aVE was 65.2% (95% CI, 11.7%-86.3%). For maternal hospitalizations, 56 influenza-positive and 345 influenza-negative women were included in the analysis, with 28.6% of influenza-positive women being vaccinated compared with 38.3% of influenza-negatives, for an aVE of 46.9% (95% CI, -2.8% to 72.5%). Analysis restricted to HIV-uninfected women resulted in 82.8% (95% CI, 40.7%-95.0%) aVE. No significant aVE (-32.5% [95% CI, -208.7% to 43.1%]) was detected among women with HIV.
Conclusions: Influenza vaccination during pregnancy prevented influenza-associated hospitalizations among young infants when infected with vaccine strains and among HIV-uninfected women.
Keywords: influenza; pregnancy; vaccine.