REVELAC-i: Progress in measuring influenza vaccine effectiveness in Latin America and way forward

Transcription

1 REVELAC-i: Progress in measuring influenza vaccine effectiveness in Latin America and way forward SARInet annual meeting, Punta Cana, May Nathalie El Omeiri On behalf of REVELAC-i network, Alba Maria Ropero-Alvarez, PAHO/WHO, Washington D.C. Family, Gender and Life Course, Immunization unit, Red para la Evaluación de Vacunas En Latino América y el Caribe influenza

2 Why measure influenza vaccine effectiveness in LAC? 40 countries in the Americas with policies in place for influenza vaccination. Over 250 M doses distributed annually. Despite the substantial increase in influenza vaccines use in LAC, no routine monitoring of influenza VE. Need for regional evidence to support current policies and guide PH measures Demonstrate the benefits of current vaccination strategies - sustain investments in influenza vaccination programs. Information for action Inform program recommendations, their impact, cost-effectiveness Inform vaccine strain selection (GIVE) Assess particular effects: waning, serial vaccination etc. 2

3 Influenza vaccine effectiveness (VE) Several features of influenza epidemiology and vaccines create unique challenges for the evaluation of IVE and the expected benefits of influenza vaccination programs. VE varies between seasons and depends on: 3 Match between vaccine and circulating strains, Host factors (age, underlying conditions,..), Prior exposure to influenza virus, Different products (TIV/LAIV, adjuvanted/unadjuvanted) Field conditions

4 How to monitor VE in LAC? Test-negative design No ethical limitations (target groups) Can build on existing influenza surveillance systems Provides valid VE estimates Reduces health-care-seeking behaviors biases, reduces the risk of misclassification of influenza status Efficient and timely Sustainable and cheap At least 28 countries across 4 continents now using the TND for annual influenza VE monitoring

5 Sullivan et al. Exp Rev. Vaccines 2014

6 The Lancet Resp Med

7 Evaluation of influenza vaccine effectiveness - A guide to the design and interpretation of observational studies, 2017 Describes challenges and the role of observational (non-randomized) influenza VE studies in evaluating influenza vaccination programs. Study designs described and their advantages and limitations reviewed. For public health scientists, it shows why VE studies have had a larger role in policy for influenza vaccines than for other vaccines. The guide also addresses the critical evaluation of influenza VE studies. 7 / eng.pdf

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9 Countries and networks reporting vaccine effectiveness annually

10 REVELAC-i network evolution (Red para la Evaluación de Vacunas de Influenza en América Latina y el Caribe) Multicenter case-control study: to estimate VE against PCR-confirmed influenza-associated SARI among vaccination target groups during the influenza season 15 REVELAC-i members Multicenter VE casecontrol study Members of the network 2012 Pilot phase (4 SH) 2013 Implementation & network launch (9 SH + 1 NH) 2014 (7 SH + pilot in Ecuador) 2016 Uruguay Costa Rica El Salvador Honduras Panama + Argentina Brazil Chile Colombia Paraguay 2015 (5 SH+ pilot in Peru) + México

11 REVELAC-i Multicenter Case-control To estimate VE against PCR-confirmed influenza-associated SARI per vaccination target groups during the influenza season. Northern hemisphere/southern Hemisphere VE per Sub-Region? 11

12 Use and formulation of seasonal influenza vaccines in the Americas, 2015 Cuba Bahamas I. Turcas & Caicos Jamaica Haiti Dominican Republic Anguilla Antigua & Barbuda Sta. Lucia Trinidad & Tobago Colombia Belize Ecuador Guatemala Honduras Peru El Salvador Nicaragua Chile Costa Rica Panama Argentina 12 Source: Country reports to PAHO, MOHs Webpage, PAHO/WHO Surveys Venezuela Brazil Paraguay Uruguay Northern Hemisphere (9) Southern Hemisphere (31) Not introduced in the public sector Policy change from NH to SH vaccine Colombia (2007) El Salvador (2011) Guatemala (2012) Cuba (2015) Honduras (2015) Costa Rica (2015)

13 Study population Country Vaccination Target groups N SARI hospitals Children Elderly Individuals with chronic conditions Argentina 6 24 months 65 years 4 Brazil 6 23 months 60 years 29 Chile 6 23 months 65 years X 6* Colombia 6 23 months 60 years 7 Costa Rica 6 months 10 years with chronic cond. 65 years 6* Cuba 6 23 months 65 years TBD El Salvador 6 59 months 60 years 4* Ecuador 6 59 months 50 years X 3 Honduras 6 35 months with chronic cond. 60 years 3* México 6 59 months; 3 9 years with chronic cond. 65 years X 46 Panamá 6 59 months 60 years 10* Paraguay 6 35 months 60 years 2 Peru 6 24 months 60 years 3 Uruguay 6 48 months 65 years 7* TOTAL 6 59 months 60 years 130 *All SARI surveillance sentinel hospitals included

14 Age, sex, date of symptoms onset, admission to intensive care, discharge status following hospitalization, dates of hospital admission and discharge, preexisting conditions, antiviral treatment, and date of admin. influenza vaccination in current and prior year, number of doses in children<9 years, date of vaccination in current year, date of respiratory specimen collection, RT-PCR results for influenza, type/subtype of influenza and lineage of influenza B, positivity for other viruses (immunofluorescence). Information collected

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16 Influenza vaccine effectiveness (%) Adjusted VE* among 6 months 5 years, LAC, % 60% 40% % 72% 66% 68% 57% 52% 50% 50% 51% 36% 20% 0% 4% 10% 2% 23% 22% 13% -20% 9 countries 7 countries 3 countries *VE 16 adjusted for age, month of symptoms onset and preexisting conditions.

17 Influenza vaccine effectiveness (%) Adjusted VE* among 60 years, LAC, % % 40% 20% 60% 62% 48% 47% 34% 28% 38% 17% 0% -20% -10% 9 countries 7 countries 3 countries *VE 17 adjusted for age, month of symptoms onset and preexisting conditions.

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19 Composición recomendada para vacunas de virus de influenza, Northern Hem Southern Hemisphere 2015 Northern Hem Southern Hemisphere 2016 Northern Hem an A/California/7/2009 (H1N1)pdm09-like virus; an A/Texas/50/2012 (H3N2)-like virus; a B/Massachusetts/2/2012-like virus. quadrivalent a B/Brisbane/60/2008-like virus. an A/California/7/2009 (H1N1)pdm09-like virus; an A/Switzerland/ /2013 (H3N2)-like virusa; a B/Phuket/3073/2013-like virus. quadrivalent a B/Brisbane/60/2008-like virus an A/California/7/2009 (H1N1)pdm09-like virus; an A/Switzerland/ /2013 (H3N2)-like virus; a B/Phuket/3073/2013-like virus. quadrivalent a B/Brisbane/60/2008-like virus. an A/California/7/2009 (H1N1)pdm09-like virus; an A/Hong Kong/4801/2014 (H3N2)-like virus; a B/Brisbane/60/2008-like virus. quadrivalent a B/Phuket/3073/2013-like virus an A/California/7/2009 (H1N1)pdm09-like virus; an A/Hong Kong/4801/2014 (H3N2)-like virus; a B/Brisbane/60/2008-like virus. Yamagata Victoria Yamagata Victoria Yamagata Victoria Victoria Yamagata Victoria Southern Hemisphere 2017 quadrivalent a B/Phuket/3073/2013-like virus. Yamagata an A/Michigan/45/2015 (H1N1)pdm09-like virus; an A/Hong Kong/4801/2014 (H3N2)-like virus; and a B/Brisbane/60/2008-like virus. Victoria quadrivalent a B/Phuket/3073/2013-like virus. Yamagata

20 REVELAC-i - What We ve Learned Feasibility of using SARI platforms + EPI Demographics, clinical, lab data completeness Vaccination status ascertainment Timeliness - active surveillance, information systems, vaccination registries Sample size Target groups IVE per type/subtype Subregion Virological information antigenic and genetic data 20

21 Influenza cases and controls included in regional VE analysis, REVELAC-i 2013 Argentina Brazil Chile Colombia Costa-Rica Honduras Panama Paraguay El Salvador Total Influenza (%) Controles ,926 (%) Total 90 1, ,620 (%) Argentina Brazil Chile Colombia Honduras Paraguay El Salvador Total Influenza (%) Controles , ,751 (%) Total , ,185 (%) Chile Colombia Paraguay Peru Total Influenza (%) Controles 1, ,166 (%) Total 2, ,686 (%) Argentina Chile Colombia Paraguay Uruguay Total Influenza (%) Controles 209 1, ,574 (%) Total 246 1, ,992 (%)

22 Conclusion Evidence from middle income countries with high vaccination uptake Moderate protection among yound infants and the elderly, supporting current vaccination strategies Strengthen REVELAC-i platform and expand VE estimation to new vaccination target groups Increase sample size for select countries and VE data timeliness for GIVE (biannual reports for the WHO influenza vaccine strain selection meeting) VE interim estimates 2017: Regional VE analysis of pooled seasons ( ) among children and the elderly. Support countries report national VE results Data analysis manual and workshop 22

23 This guide should enable public health professionals to use Stata to analyse data from TND case control studies, to estimate influenza VE The guide covers data handling and analysis including recoding, descriptive analysis, crude analysis, stratified analysis and multivariable regression. Sample dataset, based on data collected in Chile during the 2016 influenza season as part of the REVELAC-i multicenter VE study in LAC 23 (modified for educational purposes). Model do-files are included and are referenced in the relevant sections. The guide includes a supplementary section on analysis with small sample sizes. The guide also provides proposals how to report VE results

24 GRACIAS! THANK YOU! 1 st network meeting La Antigua Guatemala, nd network meeting, Cartagena de Indias, 2014 Antigua - Guatemala. 27 February rd network meeting, Santiago de Chile, March