A case-control, trial-negative design was used to evaluate the efficacy of maternal vaccination for COVID-19 in infants less than 6 months of age who had been hospitalized for suspected SARS-CoV-2 infection between July 1, 2021, and March 8, 2022. They were included infants hospitalized with COVID-19 (case infants) and infants with symptoms related to Covid-19 who had a negative SARS-CoV-2 reverse transcriptase-polymerase chain reaction or antigen test (control infants) in the study. All enrollees were treated at 30 pediatric hospitals in 22 states in the United States. The researchers sought to assess the extent to which transplacental transfer of antibodies against SARS-CoV-2 infection after maternal vaccination might confer protection against COVID-19 in infants. They assessed vaccine efficacy by comparing the probabilities of full maternal vaccination (2 doses of mRNA vaccine) between case infants and control infants during the B.1.617.2 variant (delta) release between July 1, 2021 and December 18, 2021, and the variant B.1.1.259 (omicron) between December 19, 2002 and March 8, 2022. Continue reading The researchers enrolled a total of 537 case infants (181 of whom were admitted during the period of delta variant circulation) and 512 control infants (median age 2 months in both cohorts). Overall, 16% of infants and 29% of control infants were born to mothers who had been fully vaccinated against SARS-CoV-2 during their pregnancy. Overall, 21% of infant cases required intensive care, while 12% required mechanical ventilation or vasoactive infusions. Among the infants, 2 died of COVID-19, with none of the mothers of these infants having been vaccinated during pregnancy. Maternal vaccination efficacy against hospitalization for COVID-19 was 52% (95% CI, 33%-65%) overall, 80% (95% CI, 60%-90%) in the period when the variant was circulating delta, and 38% (95% CI, 8%-58%) during the toddler period. Effectiveness against hospitalization associated with COVID-19 for each variant among infants was 69% (95% CI, 50%–80%) when maternal vaccination occurred after 20 weeks’ gestation, compared with 38% ( 95% CI, 3%-60%) when maternal vaccination was given during the first 20 weeks of pregnancy. Similarly, in both the delta-dominant and cub-dominant periods, point estimates were higher when maternal vaccination occurred after 20 weeks of gestation versus the initial 20 weeks of gestation. Limitations of the study include that the researchers are unable to assess potential biases associated with natural SARS-CoV-2 infection before or during pregnancy. Furthermore, the possibility of residual confounding arising from differences between case and control infants cannot be excluded from the analysis. Additionally, findings from the study may not apply to less severe cases of COVID-19 or other variants. “These findings provide additional support for current recommendations regarding Covid-19 vaccination during pregnancy,” the researcher wrote. Disclosure: Some of the study authors have declared affiliations with biotechnology, pharmaceutical, and/or device companies. See the original reference for a complete list of the authors’ disclosures.

Report

Halasa NB, Olson SM, Staat MA, et al; Overcoming Covid-19 researchers. Maternal vaccination and risk of hospitalization for Covid-19 in infants. N Engl J Med. Published online June 22, 2022. doi:10.1056/NEJMoa2204399

title: “Maternal Vaccination Against Covid 19 Lower Risk Of Hospitalization In Infants Klmat” ShowToc: true date: “2022-12-19” author: “Brian Rohrbaugh”

A case-control, trial-negative design was used to evaluate the efficacy of maternal vaccination for COVID-19 in infants less than 6 months of age who had been hospitalized for suspected SARS-CoV-2 infection between July 1, 2021, and March 8, 2022. They were included infants hospitalized with COVID-19 (case infants) and infants with symptoms related to Covid-19 who had a negative SARS-CoV-2 reverse transcriptase-polymerase chain reaction or antigen test (control infants) in the study. All enrollees were treated at 30 pediatric hospitals in 22 states in the United States. The researchers sought to assess the extent to which transplacental transfer of antibodies against SARS-CoV-2 infection after maternal vaccination might confer protection against COVID-19 in infants. They assessed vaccine efficacy by comparing the probabilities of full maternal vaccination (2 doses of mRNA vaccine) between case infants and control infants during the B.1.617.2 variant (delta) release between July 1, 2021 and December 18, 2021, and the variant B.1.1.259 (omicron) between December 19, 2002 and March 8, 2022. Continue reading The researchers enrolled a total of 537 case infants (181 of whom were admitted during the period of delta variant circulation) and 512 control infants (median age 2 months in both cohorts). Overall, 16% of infants and 29% of control infants were born to mothers who had been fully vaccinated against SARS-CoV-2 during their pregnancy. Overall, 21% of infant cases required intensive care, while 12% required mechanical ventilation or vasoactive infusions. Among the infants, 2 died of COVID-19, with none of the mothers of these infants having been vaccinated during pregnancy. Maternal vaccination efficacy against hospitalization for COVID-19 was 52% (95% CI, 33%-65%) overall, 80% (95% CI, 60%-90%) in the period when the variant was circulating delta, and 38% (95% CI, 8%-58%) during the toddler period. Effectiveness against hospitalization associated with COVID-19 for each variant among infants was 69% (95% CI, 50%–80%) when maternal vaccination occurred after 20 weeks’ gestation, compared with 38% ( 95% CI, 3%-60%) when maternal vaccination was given during the first 20 weeks of pregnancy. Similarly, in both the delta-dominant and cub-dominant periods, point estimates were higher when maternal vaccination occurred after 20 weeks of gestation versus the initial 20 weeks of gestation. Limitations of the study include that the researchers are unable to assess potential biases associated with natural SARS-CoV-2 infection before or during pregnancy. Furthermore, the possibility of residual confounding arising from differences between case and control infants cannot be excluded from the analysis. Additionally, findings from the study may not apply to less severe cases of COVID-19 or other variants. “These findings provide additional support for current recommendations regarding Covid-19 vaccination during pregnancy,” the researcher wrote. Disclosure: Some of the study authors have declared affiliations with biotechnology, pharmaceutical, and/or device companies. See the original reference for a complete list of the authors’ disclosures.

Report

Halasa NB, Olson SM, Staat MA, et al; Overcoming Covid-19 researchers. Maternal vaccination and risk of hospitalization for Covid-19 in infants. N Engl J Med. Published online June 22, 2022. doi:10.1056/NEJMoa2204399

title: “Maternal Vaccination Against Covid 19 Lower Risk Of Hospitalization In Infants Klmat” ShowToc: true date: “2022-10-29” author: “Nancy Hamilton”

A case-control, trial-negative design was used to evaluate the efficacy of maternal vaccination for COVID-19 in infants less than 6 months of age who had been hospitalized for suspected SARS-CoV-2 infection between July 1, 2021, and March 8, 2022. They were included infants hospitalized with COVID-19 (case infants) and infants with symptoms related to Covid-19 who had a negative SARS-CoV-2 reverse transcriptase-polymerase chain reaction or antigen test (control infants) in the study. All enrollees were treated at 30 pediatric hospitals in 22 states in the United States. The researchers sought to assess the extent to which transplacental transfer of antibodies against SARS-CoV-2 infection after maternal vaccination might confer protection against COVID-19 in infants. They assessed vaccine efficacy by comparing the probabilities of full maternal vaccination (2 doses of mRNA vaccine) between case infants and control infants during the B.1.617.2 variant (delta) release between July 1, 2021 and December 18, 2021, and the variant B.1.1.259 (omicron) between December 19, 2002 and March 8, 2022. Continue reading The researchers enrolled a total of 537 case infants (181 of whom were admitted during the period of delta variant circulation) and 512 control infants (median age 2 months in both cohorts). Overall, 16% of infants and 29% of control infants were born to mothers who had been fully vaccinated against SARS-CoV-2 during their pregnancy. Overall, 21% of infant cases required intensive care, while 12% required mechanical ventilation or vasoactive infusions. Among the infants, 2 died of COVID-19, with none of the mothers of these infants having been vaccinated during pregnancy. Maternal vaccination efficacy against hospitalization for COVID-19 was 52% (95% CI, 33%-65%) overall, 80% (95% CI, 60%-90%) in the period when the variant was circulating delta, and 38% (95% CI, 8%-58%) during the toddler period. Effectiveness against hospitalization associated with COVID-19 for each variant among infants was 69% (95% CI, 50%–80%) when maternal vaccination occurred after 20 weeks’ gestation, compared with 38% ( 95% CI, 3%-60%) when maternal vaccination was given during the first 20 weeks of pregnancy. Similarly, in both the delta-dominant and cub-dominant periods, point estimates were higher when maternal vaccination occurred after 20 weeks of gestation versus the initial 20 weeks of gestation. Limitations of the study include that the researchers are unable to assess potential biases associated with natural SARS-CoV-2 infection before or during pregnancy. Furthermore, the possibility of residual confounding arising from differences between case and control infants cannot be excluded from the analysis. Additionally, findings from the study may not apply to less severe cases of COVID-19 or other variants. “These findings provide additional support for current recommendations regarding Covid-19 vaccination during pregnancy,” the researcher wrote. Disclosure: Some of the study authors have declared affiliations with biotechnology, pharmaceutical, and/or device companies. See the original reference for a complete list of the authors’ disclosures.

Report

Halasa NB, Olson SM, Staat MA, et al; Overcoming Covid-19 researchers. Maternal vaccination and risk of hospitalization for Covid-19 in infants. N Engl J Med. Published online June 22, 2022. doi:10.1056/NEJMoa2204399

title: “Maternal Vaccination Against Covid 19 Lower Risk Of Hospitalization In Infants Klmat” ShowToc: true date: “2022-12-16” author: “Michael Mueller”

A case-control, trial-negative design was used to evaluate the efficacy of maternal vaccination for COVID-19 in infants less than 6 months of age who had been hospitalized for suspected SARS-CoV-2 infection between July 1, 2021, and March 8, 2022. They were included infants hospitalized with COVID-19 (case infants) and infants with symptoms related to Covid-19 who had a negative SARS-CoV-2 reverse transcriptase-polymerase chain reaction or antigen test (control infants) in the study. All enrollees were treated at 30 pediatric hospitals in 22 states in the United States. The researchers sought to assess the extent to which transplacental transfer of antibodies against SARS-CoV-2 infection after maternal vaccination might confer protection against COVID-19 in infants. They assessed vaccine efficacy by comparing the probabilities of full maternal vaccination (2 doses of mRNA vaccine) between case infants and control infants during the B.1.617.2 variant (delta) release between July 1, 2021 and December 18, 2021, and the variant B.1.1.259 (omicron) between December 19, 2002 and March 8, 2022. Continue reading The researchers enrolled a total of 537 case infants (181 of whom were admitted during the period of delta variant circulation) and 512 control infants (median age 2 months in both cohorts). Overall, 16% of infants and 29% of control infants were born to mothers who had been fully vaccinated against SARS-CoV-2 during their pregnancy. Overall, 21% of infant cases required intensive care, while 12% required mechanical ventilation or vasoactive infusions. Among the infants, 2 died of COVID-19, with none of the mothers of these infants having been vaccinated during pregnancy. Maternal vaccination efficacy against hospitalization for COVID-19 was 52% (95% CI, 33%-65%) overall, 80% (95% CI, 60%-90%) in the period when the variant was circulating delta, and 38% (95% CI, 8%-58%) during the toddler period. Effectiveness against hospitalization associated with COVID-19 for each variant among infants was 69% (95% CI, 50%–80%) when maternal vaccination occurred after 20 weeks’ gestation, compared with 38% ( 95% CI, 3%-60%) when maternal vaccination was given during the first 20 weeks of pregnancy. Similarly, in both the delta-dominant and cub-dominant periods, point estimates were higher when maternal vaccination occurred after 20 weeks of gestation versus the initial 20 weeks of gestation. Limitations of the study include that the researchers are unable to assess potential biases associated with natural SARS-CoV-2 infection before or during pregnancy. Furthermore, the possibility of residual confounding arising from differences between case and control infants cannot be excluded from the analysis. Additionally, findings from the study may not apply to less severe cases of COVID-19 or other variants. “These findings provide additional support for current recommendations regarding Covid-19 vaccination during pregnancy,” the researcher wrote. Disclosure: Some of the study authors have declared affiliations with biotechnology, pharmaceutical, and/or device companies. See the original reference for a complete list of the authors’ disclosures.

Report

Halasa NB, Olson SM, Staat MA, et al; Overcoming Covid-19 researchers. Maternal vaccination and risk of hospitalization for Covid-19 in infants. N Engl J Med. Published online June 22, 2022. doi:10.1056/NEJMoa2204399