tetano
Editor, Senior Moderator
PLoS One. 2016 Aug 3;11(8):e0160342. doi: 10.1371/journal.pone.0160342. eCollection 2016.
[h=1]Infant Respiratory Outcomes Associated with Prenatal Exposure to Maternal 2009 A/H1N1 Influenza Vaccination.[/h] Fell DB[SUP]1[/SUP], Wilson K[SUP]2,[/SUP][SUP]3,[/SUP][SUP]4[/SUP], Ducharme R[SUP]3,[/SUP][SUP]4[/SUP], Hawken S[SUP]3,[/SUP][SUP]4,[/SUP][SUP]5[/SUP], Sprague AE[SUP]1[/SUP], Kwong JC[SUP]3,[/SUP][SUP]6,[/SUP][SUP]7,[/SUP][SUP]8[/SUP], Smith G[SUP]9[/SUP], Wen SW[SUP]4,[/SUP][SUP]10[/SUP], Walker MC[SUP]1,[/SUP][SUP]4,[/SUP][SUP]10,[/SUP][SUP]11[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Infants are at high risk for influenza illness, but are ineligible for vaccination before 6 months. Transfer of maternal antibodies to the fetus has been demonstrated for 2009 A/H1N1 pandemic vaccines; however, clinical effectiveness is unknown. Our objective was to evaluate the association between 2009 A/H1N1 pandemic vaccination during pregnancy and rates of infant influenza and pneumonia.
[h=4]METHODS:[/h] We linked a population-based birth cohort to administrative databases to measure rates of influenza and pneumonia diagnosed during ambulatory physician visits, hospitalizations and emergency department visits during one year of follow-up. We estimated incidence rate ratios and 95% confidence intervals (95% CI) using Poisson regression, comparing infants born to A/H1N1-vaccinated women (vaccine-exposed infants) with unexposed infants, adjusted for confounding using high-dimensional propensity scores.
[h=4]RESULTS:[/h] Among 117,335 infants in the study, 36,033 (31%) were born to A/H1N1-vaccinated women. Crude rates of influenza during the pandemic (per 100,000 infant-days) for vaccine-exposed and unexposed infants were similar (2.19, 95% CI: 1.27-3.76 and 3.60, 95% CI: 2.51-5.14, respectively), as were crude rates of influenza and pneumonia combined. We did not observe any significant differences in rates of study outcomes between study groups during the second wave of the 2009 A/H1N1 pandemic, nor during any post-pandemic time period.
[h=4]CONCLUSION:[/h] We observed no difference in rates of study outcomes among infants born to A/H1N1-vaccinated mothers relative to unexposed infants born during the second A/H1N1 pandemic wave; however, due to late availability of the pandemic vaccine, the available follow-up time during the pandemic time period was very limited.
PMID: 27486858 DOI: 10.1371/journal.pone.0160342
[PubMed - in process] Free full text
[h=1]Infant Respiratory Outcomes Associated with Prenatal Exposure to Maternal 2009 A/H1N1 Influenza Vaccination.[/h] Fell DB[SUP]1[/SUP], Wilson K[SUP]2,[/SUP][SUP]3,[/SUP][SUP]4[/SUP], Ducharme R[SUP]3,[/SUP][SUP]4[/SUP], Hawken S[SUP]3,[/SUP][SUP]4,[/SUP][SUP]5[/SUP], Sprague AE[SUP]1[/SUP], Kwong JC[SUP]3,[/SUP][SUP]6,[/SUP][SUP]7,[/SUP][SUP]8[/SUP], Smith G[SUP]9[/SUP], Wen SW[SUP]4,[/SUP][SUP]10[/SUP], Walker MC[SUP]1,[/SUP][SUP]4,[/SUP][SUP]10,[/SUP][SUP]11[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Infants are at high risk for influenza illness, but are ineligible for vaccination before 6 months. Transfer of maternal antibodies to the fetus has been demonstrated for 2009 A/H1N1 pandemic vaccines; however, clinical effectiveness is unknown. Our objective was to evaluate the association between 2009 A/H1N1 pandemic vaccination during pregnancy and rates of infant influenza and pneumonia.
[h=4]METHODS:[/h] We linked a population-based birth cohort to administrative databases to measure rates of influenza and pneumonia diagnosed during ambulatory physician visits, hospitalizations and emergency department visits during one year of follow-up. We estimated incidence rate ratios and 95% confidence intervals (95% CI) using Poisson regression, comparing infants born to A/H1N1-vaccinated women (vaccine-exposed infants) with unexposed infants, adjusted for confounding using high-dimensional propensity scores.
[h=4]RESULTS:[/h] Among 117,335 infants in the study, 36,033 (31%) were born to A/H1N1-vaccinated women. Crude rates of influenza during the pandemic (per 100,000 infant-days) for vaccine-exposed and unexposed infants were similar (2.19, 95% CI: 1.27-3.76 and 3.60, 95% CI: 2.51-5.14, respectively), as were crude rates of influenza and pneumonia combined. We did not observe any significant differences in rates of study outcomes between study groups during the second wave of the 2009 A/H1N1 pandemic, nor during any post-pandemic time period.
[h=4]CONCLUSION:[/h] We observed no difference in rates of study outcomes among infants born to A/H1N1-vaccinated mothers relative to unexposed infants born during the second A/H1N1 pandemic wave; however, due to late availability of the pandemic vaccine, the available follow-up time during the pandemic time period was very limited.
PMID: 27486858 DOI: 10.1371/journal.pone.0160342
[PubMed - in process] Free full text