tetano
Editor, Senior Moderator
Vaccine X. 2019 Nov 2;3:100047. doi: 10.1016/j.jvacx.2019.100047. eCollection 2019 Dec 10. [h=1]Influenza vaccine effectiveness against hospitalizations in children and older adults-Data from South America, 2013-2017. A test negative design.[/h]
Sofia Arriola C[SUP]1[/SUP], El Omeiri N[SUP]2[/SUP], Azziz-Baumgartner E[SUP]1[/SUP], Thompson MG[SUP]1[/SUP], Sotomayor-Proschle V[SUP]3[/SUP], Fasce RA[SUP]4[/SUP], Von Horoch M[SUP]5[/SUP], Enrique Carrizo Olalla J[SUP]6[/SUP], Aparecida Ferreira de Almeida W[SUP]7[/SUP], Palacios J[SUP]8[/SUP], Palekar R[SUP]9[/SUP], Couto P[SUP]9[/SUP], Descalzo M[SUP]10[/SUP], Mar?a Ropero-?lvarez A[SUP]2[/SUP]; REVELAC-I network participants.
[h=3]Collaborators (24)[/h]
[h=3]Author information[/h] 1 Influenza Division, US Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA. 2 Department of Family Gender and Life Course/Immunization, Pan American Health Organization/World Health Organization (PAHO/WHO), Washington, DC, USA. 3 Epidemiology Department, Ministry of Health, Chile. 4 Public Health Institute, Ministry of Health, Chile. 5 Health Surveillance Unit, Ministry of Public Health and Social Welfare, Paraguay. 6 Epidemiology Department, Ministry of Health, Argentina. 7 Department of Communicable Diseases Surveillance, Ministry of Health, Brazil. 8 Ministry of Health, Colombia. 9 Department of Public Health Emergencies, PAHO/WHO, Washington, DC, USA. 10 PAHO/WHO International Consultant, USA.
[h=3]Abstract[/h] [h=4]Background:[/h] In 2013, the Pan American Health Organization established a multi-site, multi-country network to evaluate influenza vaccine effectiveness (VE). We pooled data from five consecutive seasons in five countries to conduct an analysis of southern hemisphere VE against laboratory-confirmed influenza hospitalizations in young children and older adults.
[h=4]Methods:[/h] We used a test-negative design to estimate VE against laboratory-confirmed influenza in hospitalized young children (aged 6─24 months) and older adults (aged ≥60 years) in Argentina, Brazil, Chile, Colombia, and Paraguay. Following country-specific influenza surveillance protocol, hospitalized persons with severe acute respiratory infections (SARI) at 48 sentinel hospitals (March 2013-December 2017) were tested for influenza virus infection by rRT-PCR. VE was estimated for young children and older adults using logistic random effects models accounting for cluster (country), adjusting for sex, age (months for children, and age-in-year categories for adults), calendar year, country, preexisting conditions, month of illness onset and prior vaccination as an effect modifier for the analysis in adults.
[h=4]Results:[/h] We included 8426 SARI cases (2389 children and 6037 adults) in the VE analyses. Among young children, VE against SARI hospitalization associated with any influenza virus was 43% (95%CI: 33%, 51%) for children who received two doses, but was 20% (95%CI: -16%, 45%) and not statistically significant for those who received one dose in a given season. Among older adults, overall VE against SARI hospitalization associated with any influenza virus was 41% (95%CI: 28%, 52%), 45% (95%CI: 34%, 53%) against A(H3N2), 40% (95%CI: 18%, 56%) against A(H1N1)pdm09, and 20% (95%CI: -40%, 54%) against influenza B viruses.
[h=4]Conclusions:[/h] Our results suggest that over the five-year study period, influenza vaccination programs in five South American countries prevented more than one-third of laboratory confirmed influenza-associated hospitalizations in young children receiving the recommended two doses and vaccinated older adults.
[h=4]KEYWORDS:[/h] Adults; Children; Hospitalizations; Influenza vaccine effectiveness; Latin America; Severe acute respiratory infections; Southern hemisphere; Test-negative case-control design
PMID: 31867577 PMCID: PMC6904815 DOI: 10.1016/j.jvacx.2019.100047
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Sofia Arriola C[SUP]1[/SUP], El Omeiri N[SUP]2[/SUP], Azziz-Baumgartner E[SUP]1[/SUP], Thompson MG[SUP]1[/SUP], Sotomayor-Proschle V[SUP]3[/SUP], Fasce RA[SUP]4[/SUP], Von Horoch M[SUP]5[/SUP], Enrique Carrizo Olalla J[SUP]6[/SUP], Aparecida Ferreira de Almeida W[SUP]7[/SUP], Palacios J[SUP]8[/SUP], Palekar R[SUP]9[/SUP], Couto P[SUP]9[/SUP], Descalzo M[SUP]10[/SUP], Mar?a Ropero-?lvarez A[SUP]2[/SUP]; REVELAC-I network participants.
[h=3]Collaborators (24)[/h]
[h=3]Author information[/h] 1 Influenza Division, US Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA. 2 Department of Family Gender and Life Course/Immunization, Pan American Health Organization/World Health Organization (PAHO/WHO), Washington, DC, USA. 3 Epidemiology Department, Ministry of Health, Chile. 4 Public Health Institute, Ministry of Health, Chile. 5 Health Surveillance Unit, Ministry of Public Health and Social Welfare, Paraguay. 6 Epidemiology Department, Ministry of Health, Argentina. 7 Department of Communicable Diseases Surveillance, Ministry of Health, Brazil. 8 Ministry of Health, Colombia. 9 Department of Public Health Emergencies, PAHO/WHO, Washington, DC, USA. 10 PAHO/WHO International Consultant, USA.
[h=3]Abstract[/h] [h=4]Background:[/h] In 2013, the Pan American Health Organization established a multi-site, multi-country network to evaluate influenza vaccine effectiveness (VE). We pooled data from five consecutive seasons in five countries to conduct an analysis of southern hemisphere VE against laboratory-confirmed influenza hospitalizations in young children and older adults.
[h=4]Methods:[/h] We used a test-negative design to estimate VE against laboratory-confirmed influenza in hospitalized young children (aged 6─24 months) and older adults (aged ≥60 years) in Argentina, Brazil, Chile, Colombia, and Paraguay. Following country-specific influenza surveillance protocol, hospitalized persons with severe acute respiratory infections (SARI) at 48 sentinel hospitals (March 2013-December 2017) were tested for influenza virus infection by rRT-PCR. VE was estimated for young children and older adults using logistic random effects models accounting for cluster (country), adjusting for sex, age (months for children, and age-in-year categories for adults), calendar year, country, preexisting conditions, month of illness onset and prior vaccination as an effect modifier for the analysis in adults.
[h=4]Results:[/h] We included 8426 SARI cases (2389 children and 6037 adults) in the VE analyses. Among young children, VE against SARI hospitalization associated with any influenza virus was 43% (95%CI: 33%, 51%) for children who received two doses, but was 20% (95%CI: -16%, 45%) and not statistically significant for those who received one dose in a given season. Among older adults, overall VE against SARI hospitalization associated with any influenza virus was 41% (95%CI: 28%, 52%), 45% (95%CI: 34%, 53%) against A(H3N2), 40% (95%CI: 18%, 56%) against A(H1N1)pdm09, and 20% (95%CI: -40%, 54%) against influenza B viruses.
[h=4]Conclusions:[/h] Our results suggest that over the five-year study period, influenza vaccination programs in five South American countries prevented more than one-third of laboratory confirmed influenza-associated hospitalizations in young children receiving the recommended two doses and vaccinated older adults.
[h=4]KEYWORDS:[/h] Adults; Children; Hospitalizations; Influenza vaccine effectiveness; Latin America; Severe acute respiratory infections; Southern hemisphere; Test-negative case-control design
PMID: 31867577 PMCID: PMC6904815 DOI: 10.1016/j.jvacx.2019.100047
Free full text