Influenza Vaccine Effectiveness Against Hospitalizations in Children and Older Adults-Data from South America, 2013-2017. A Test Negative Design

Overview

Journal Vaccine X

Date 2019 Dec 24

PMID 31867577

Citations 11

Authors

Carmen Sofia Arriola

Nathalie El Omeiri

Eduardo Azziz-Baumgartner

Mark G Thompson

Viviana Sotomayor-Proschle

Rodrigo A Fasce

Martha Von Horoch

Jose Enrique Carrizo Olalla

Walquiria Aparecida Ferreira de Almeida

Jacqueline Palacios

Rakhee Palekar

Paula Couto

Miguel Descalzo

Alba Maria Ropero-Alvarez

Affiliations

Soon will be listed here.

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

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References

Sullivan S, Tchetgen Tchetgen E, Cowling B . Theoretical Basis of the Test-Negative Study Design for Assessment of Influenza Vaccine Effectiveness. Am J Epidemiol. 2016; 184(5):345-53. PMC: 5013887. DOI: 10.1093/aje/kww064. View

Jackson M . Use of self-reported vaccination status can bias vaccine effectiveness estimates from test-negative studies. Vaccine X. 2021; 1:100003. PMC: 6668222. DOI: 10.1016/j.jvacx.2018.100003. View

Englund J, Walter E, Fairchok M, Monto A, Neuzil K . A comparison of 2 influenza vaccine schedules in 6- to 23-month-old children. Pediatrics. 2005; 115(4):1039-47. DOI: 10.1542/peds.2004-2373. View

Jackson M, Nelson J . The test-negative design for estimating influenza vaccine effectiveness. Vaccine. 2013; 31(17):2165-8. DOI: 10.1016/j.vaccine.2013.02.053. View

Neuzil K, Jackson L, Nelson J, Klimov A, Cox N, Bridges C . Immunogenicity and reactogenicity of 1 versus 2 doses of trivalent inactivated influenza vaccine in vaccine-naive 5-8-year-old children. J Infect Dis. 2006; 194(8):1032-9. DOI: 10.1086/507309. View

Belongia E, Skowronski D, McLean H, Chambers C, Sundaram M, De Serres G . Repeated annual influenza vaccination and vaccine effectiveness: review of evidence. Expert Rev Vaccines. 2017; 16(7):1-14. DOI: 10.1080/14760584.2017.1334554. View

Thompson M, Clippard J, Petrie J, Jackson M, McLean H, Gaglani M . Influenza Vaccine Effectiveness for Fully and Partially Vaccinated Children 6 Months to 8 Years Old During 2011-2012 and 2012-2013: The Importance of Two Priming Doses. Pediatr Infect Dis J. 2015; 35(3):299-308. PMC: 5218633. DOI: 10.1097/INF.0000000000001006. View

Valenciano M, Kissling E, Ciancio B, Moren A . Study designs for timely estimation of influenza vaccine effectiveness using European sentinel practitioner networks. Vaccine. 2010; 28(46):7381-8. DOI: 10.1016/j.vaccine.2010.09.010. View

Sotomayor V, Fasce R, Vergara N, de la Fuente F, Loayza S, Palekar R . Estimating the burden of influenza-associated hospitalizations and deaths in Chile during 2012-2014. Influenza Other Respir Viruses. 2018; 12(1):138-145. PMC: 5818356. DOI: 10.1111/irv.12502. View

10.

Thompson M, Pierse N, Huang Q, Prasad N, Duque J, Newbern E . Influenza vaccine effectiveness in preventing influenza-associated intensive care admissions and attenuating severe disease among adults in New Zealand 2012-2015. Vaccine. 2018; 36(39):5916-5925. DOI: 10.1016/j.vaccine.2018.07.028. View

11.

El Omeiri N, Azziz-Baumgartner E, Clara W, Guzman-Saborio G, Elas M, Mejia H . Pilot to evaluate the feasibility of measuring seasonal influenza vaccine effectiveness using surveillance platforms in Central-America, 2012. BMC Public Health. 2015; 15:673. PMC: 4504410. DOI: 10.1186/s12889-015-2001-1. View

12.

Belongia E, Simpson M, King J, Sundaram M, Kelley N, Osterholm M . Variable influenza vaccine effectiveness by subtype: a systematic review and meta-analysis of test-negative design studies. Lancet Infect Dis. 2016; 16(8):942-51. DOI: 10.1016/S1473-3099(16)00129-8. View

13.

Ramsay L, Buchan S, Stirling R, Cowling B, Feng S, Kwong J . The impact of repeated vaccination on influenza vaccine effectiveness: a systematic review and meta-analysis. BMC Med. 2019; 17(1):9. PMC: 6327561. DOI: 10.1186/s12916-018-1239-8. View

14.

Foppa I, Ferdinands J, Chung J, Flannery B, Fry A . Vaccination history as a confounder of studies of influenza vaccine effectiveness. Vaccine X. 2019; 1:100008. PMC: 6668227. DOI: 10.1016/j.jvacx.2019.100008. View

15.

El Omeiri N, Azziz-Baumgartner E, Thompson M, Clara W, Cerpa M, Palekar R . Seasonal influenza vaccine effectiveness against laboratory-confirmed influenza hospitalizations - Latin America, 2013. Vaccine. 2017; 36(24):3555-3566. PMC: 5988548. DOI: 10.1016/j.vaccine.2017.06.036. View

16.

Fu C, Xu J, Lin J, Wang M, Li K, Ge J . Concurrent and cross-season protection of inactivated influenza vaccine against A(H1N1)pdm09 illness among young children: 2012-2013 case-control evaluation of influenza vaccine effectiveness. Vaccine. 2015; 33(25):2917-21. DOI: 10.1016/j.vaccine.2015.04.063. View

17.

Foppa I, Haber M, Ferdinands J, Shay D . The case test-negative design for studies of the effectiveness of influenza vaccine. Vaccine. 2013; 31(30):3104-9. DOI: 10.1016/j.vaccine.2013.04.026. View

18.

Rondy M, El Omeiri N, Thompson M, Leveque A, Moren A, Sullivan S . Effectiveness of influenza vaccines in preventing severe influenza illness among adults: A systematic review and meta-analysis of test-negative design case-control studies. J Infect. 2017; 75(5):381-394. PMC: 5912669. DOI: 10.1016/j.jinf.2017.09.010. View

19.

Sullivan S, Feng S, Cowling B . Potential of the test-negative design for measuring influenza vaccine effectiveness: a systematic review. Expert Rev Vaccines. 2014; 13(12):1571-91. PMC: 4277796. DOI: 10.1586/14760584.2014.966695. View

20.

Eisenberg K, Szilagyi P, Fairbrother G, Griffin M, Staat M, Shone L . Vaccine effectiveness against laboratory-confirmed influenza in children 6 to 59 months of age during the 2003-2004 and 2004-2005 influenza seasons. Pediatrics. 2008; 122(5):911-9. PMC: 3695734. DOI: 10.1542/peds.2007-3304. View