tetano
Editor, Senior Moderator
Vaccine. 2018 Feb 2. pii: S0264-410X(18)30094-X. doi: 10.1016/j.vaccine.2018.01.045. [Epub ahead of print]
[h=1]Influenza vaccine effectiveness in older adults compared with younger adults over five seasons.[/h] Russell K[SUP]1[/SUP], Chung JR[SUP]2[/SUP], Monto AS[SUP]3[/SUP], Martin ET[SUP]3[/SUP], Belongia EA[SUP]4[/SUP], McLean HQ[SUP]4[/SUP], Gaglani M[SUP]5[/SUP], Murthy K[SUP]5[/SUP], Zimmerman RK[SUP]6[/SUP], Nowalk MP[SUP]6[/SUP], Jackson ML[SUP]7[/SUP], Jackson LA[SUP]7[/SUP], Flannery B[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] There have been inconsistent reports of decreased vaccine effectiveness (VE) against influenza viruses among older adults (aged ≥ 65 years) compared with younger adults in the United States. A direct comparison of VE over multiple seasons is needed to assess the consistency of these observations.
[h=4]METHODS:[/h] We performed a pooled analysis of VE over 5 seasons among adults aged ≥ 18 years who were systematically enrolled in the U.S. Flu VE Network. Outpatients with medically-attended acute respiratory illness (cough with illness onset ≤ 7 days prior to enrollment) were tested for influenza by reverse transcription polymerase chain reaction. We compared differences in VE and vaccine failures among older adult age group (65-74, ≥75, and ≥ 65 years) to adults aged 18-49 years by influenza type and subtype using interaction terms to test for statistical significance and stratified by prior season vaccination status.
[h=4]RESULTS:[/h] Analysis included 20,022 adults aged ≥ 18 years enrolled during the 2011-12 through 2015-16 influenza seasons; 4,785 (24%) tested positive for influenza. VE among patients aged ≥ 65 years was not significantly lower than VE among patients aged 18-49 years against any subtype with no significant interaction of age and vaccination. VE against A(H3N2) viruses was 14% (95% confidence interval [CI] -14% to 36%) for adults ≥ 65 years and 21% (CI 9-32%) for adults 18-49 years. VE against A(H1N1)pdm09 was 49% (95% CI 22-66%) for adults ≥ 65 years and 48% (95% CI 41-54%) for adults 18-49 years and against B viruses was 62% (95% CI 44-74%) for adults ≥ 65 years and 55% (95% CI 45-63%) for adults 18-49 years. There was no significant interaction of age and vaccination for separate strata of prior vaccination status.
[h=4]CONCLUSIONS:[/h] Over 5 seasons, influenza vaccination provided similar levels of protection among older and younger adults, with lower levels of protection against influenza A(H3N2) in all ages.
Published by Elsevier Ltd.
[h=4]KEYWORDS:[/h] Human; Influenza; Influenza vaccine effectiveness; Influenza vaccines; Older adults
PMID: 29402578 DOI: 10.1016/j.vaccine.2018.01.045
[h=1]Influenza vaccine effectiveness in older adults compared with younger adults over five seasons.[/h] Russell K[SUP]1[/SUP], Chung JR[SUP]2[/SUP], Monto AS[SUP]3[/SUP], Martin ET[SUP]3[/SUP], Belongia EA[SUP]4[/SUP], McLean HQ[SUP]4[/SUP], Gaglani M[SUP]5[/SUP], Murthy K[SUP]5[/SUP], Zimmerman RK[SUP]6[/SUP], Nowalk MP[SUP]6[/SUP], Jackson ML[SUP]7[/SUP], Jackson LA[SUP]7[/SUP], Flannery B[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] There have been inconsistent reports of decreased vaccine effectiveness (VE) against influenza viruses among older adults (aged ≥ 65 years) compared with younger adults in the United States. A direct comparison of VE over multiple seasons is needed to assess the consistency of these observations.
[h=4]METHODS:[/h] We performed a pooled analysis of VE over 5 seasons among adults aged ≥ 18 years who were systematically enrolled in the U.S. Flu VE Network. Outpatients with medically-attended acute respiratory illness (cough with illness onset ≤ 7 days prior to enrollment) were tested for influenza by reverse transcription polymerase chain reaction. We compared differences in VE and vaccine failures among older adult age group (65-74, ≥75, and ≥ 65 years) to adults aged 18-49 years by influenza type and subtype using interaction terms to test for statistical significance and stratified by prior season vaccination status.
[h=4]RESULTS:[/h] Analysis included 20,022 adults aged ≥ 18 years enrolled during the 2011-12 through 2015-16 influenza seasons; 4,785 (24%) tested positive for influenza. VE among patients aged ≥ 65 years was not significantly lower than VE among patients aged 18-49 years against any subtype with no significant interaction of age and vaccination. VE against A(H3N2) viruses was 14% (95% confidence interval [CI] -14% to 36%) for adults ≥ 65 years and 21% (CI 9-32%) for adults 18-49 years. VE against A(H1N1)pdm09 was 49% (95% CI 22-66%) for adults ≥ 65 years and 48% (95% CI 41-54%) for adults 18-49 years and against B viruses was 62% (95% CI 44-74%) for adults ≥ 65 years and 55% (95% CI 45-63%) for adults 18-49 years. There was no significant interaction of age and vaccination for separate strata of prior vaccination status.
[h=4]CONCLUSIONS:[/h] Over 5 seasons, influenza vaccination provided similar levels of protection among older and younger adults, with lower levels of protection against influenza A(H3N2) in all ages.
Published by Elsevier Ltd.
[h=4]KEYWORDS:[/h] Human; Influenza; Influenza vaccine effectiveness; Influenza vaccines; Older adults
PMID: 29402578 DOI: 10.1016/j.vaccine.2018.01.045