Respiratory syncytial virus vaccination during pregnancy and effects in infants

<p><strong>BACKGROUND</strong></p> <p>Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants.</p> <p><strong>METHODS</strong>&...

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Main Authors: Madhi, SA, Polack, FP, Piedra, PA, Vatish, M, Snape, M, Prepare Study Group
Format: Journal article
Language:English
Published: Massachusetts Medical Society 2020
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author Madhi, SA
Polack, FP
Piedra, PA
Vatish, M
Snape, M
Prepare Study Group
author_facet Madhi, SA
Polack, FP
Piedra, PA
Vatish, M
Snape, M
Prepare Study Group
author_sort Madhi, SA
collection OXFORD
description <p><strong>BACKGROUND</strong></p> <p>Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants.</p> <p><strong>METHODS</strong></p> <p>Healthy pregnant women, at 28 weeks 0 days through 36 weeks 0 days of gestation, with an expected delivery date near the start of the RSV season, were randomly assigned in an overall ratio of approximately 2:1 to receive a single intramuscular dose of RSV fusion (F) protein nanoparticle vaccine or placebo. Infants were followed for 180 days to assess outcomes related to lower respiratory tract infection and for 364 days to assess safety. The primary end point was RSV-associated, medically significant lower respiratory tract infection up to 90 days of life, and the primary analysis of vaccine efficacy against the primary end point was performed in the per-protocol population of infants (prespecified criterion for success, lower bound of the 97.52% confidence interval [CI] of ≥30%).</p> <p><strong>RESULTS</strong></p> <p>A total of 4636 women underwent randomization, and there were 4579 live births. During the first 90 days of life, the percentage of infants with RSV-associated, medically significant lower respiratory tract infection was 1.5% in the vaccine group and 2.4% in the placebo group (vaccine efficacy, 39.4%; 97.52% CI, −1.0 to 63.7; 95% CI, 5.3 to 61.2). The corresponding percentages for RSV-associated lower respiratory tract infection with severe hypoxemia were 0.5% and 1.0% (vaccine efficacy, 48.3%; 95% CI, −8.2 to 75.3), and the percentages for hospitalization for RSV-associated lower respiratory tract infection were 2.1% and 3.7% (vaccine efficacy, 44.4%; 95% CI, 19.6 to 61.5). Local injection-site reactions among the women were more common with vaccine than with placebo (40.7% vs. 9.9%), but the percentages of participants who had other adverse events were similar in the two groups.</p> <p><strong>CONCLUSIONS</strong></p> <p>RSV F protein nanoparticle vaccination in pregnant women did not meet the prespecified success criterion for efficacy against RSV-associated, medically significant lower respiratory tract infection in infants up to 90 days of life. The suggestion of a possible benefit with respect to other end-point events involving RSV-associated respiratory disease in infants warrants further study. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov NCT02624947. opens in new tab.)</p>
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spelling oxford-uuid:020cc48b-94ec-4ebf-a3c2-a6d6eb2d8f852022-03-26T08:38:23ZRespiratory syncytial virus vaccination during pregnancy and effects in infantsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:020cc48b-94ec-4ebf-a3c2-a6d6eb2d8f85EnglishSymplectic ElementsMassachusetts Medical Society2020Madhi, SAPolack, FPPiedra, PAVatish, MSnape, MPrepare Study Group<p><strong>BACKGROUND</strong></p> <p>Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants.</p> <p><strong>METHODS</strong></p> <p>Healthy pregnant women, at 28 weeks 0 days through 36 weeks 0 days of gestation, with an expected delivery date near the start of the RSV season, were randomly assigned in an overall ratio of approximately 2:1 to receive a single intramuscular dose of RSV fusion (F) protein nanoparticle vaccine or placebo. Infants were followed for 180 days to assess outcomes related to lower respiratory tract infection and for 364 days to assess safety. The primary end point was RSV-associated, medically significant lower respiratory tract infection up to 90 days of life, and the primary analysis of vaccine efficacy against the primary end point was performed in the per-protocol population of infants (prespecified criterion for success, lower bound of the 97.52% confidence interval [CI] of ≥30%).</p> <p><strong>RESULTS</strong></p> <p>A total of 4636 women underwent randomization, and there were 4579 live births. During the first 90 days of life, the percentage of infants with RSV-associated, medically significant lower respiratory tract infection was 1.5% in the vaccine group and 2.4% in the placebo group (vaccine efficacy, 39.4%; 97.52% CI, −1.0 to 63.7; 95% CI, 5.3 to 61.2). The corresponding percentages for RSV-associated lower respiratory tract infection with severe hypoxemia were 0.5% and 1.0% (vaccine efficacy, 48.3%; 95% CI, −8.2 to 75.3), and the percentages for hospitalization for RSV-associated lower respiratory tract infection were 2.1% and 3.7% (vaccine efficacy, 44.4%; 95% CI, 19.6 to 61.5). Local injection-site reactions among the women were more common with vaccine than with placebo (40.7% vs. 9.9%), but the percentages of participants who had other adverse events were similar in the two groups.</p> <p><strong>CONCLUSIONS</strong></p> <p>RSV F protein nanoparticle vaccination in pregnant women did not meet the prespecified success criterion for efficacy against RSV-associated, medically significant lower respiratory tract infection in infants up to 90 days of life. The suggestion of a possible benefit with respect to other end-point events involving RSV-associated respiratory disease in infants warrants further study. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov NCT02624947. opens in new tab.)</p>
spellingShingle Madhi, SA
Polack, FP
Piedra, PA
Vatish, M
Snape, M
Prepare Study Group
Respiratory syncytial virus vaccination during pregnancy and effects in infants
title Respiratory syncytial virus vaccination during pregnancy and effects in infants
title_full Respiratory syncytial virus vaccination during pregnancy and effects in infants
title_fullStr Respiratory syncytial virus vaccination during pregnancy and effects in infants
title_full_unstemmed Respiratory syncytial virus vaccination during pregnancy and effects in infants
title_short Respiratory syncytial virus vaccination during pregnancy and effects in infants
title_sort respiratory syncytial virus vaccination during pregnancy and effects in infants
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