Randomized evaluation of live attenuated vs. inactivated influenza vaccines in schools (RELATIVES) cluster randomized trial: Pilot results from a household surveillance study to assess direct and indirect protection from influenza vaccination. Issue 38 (11th September 2015)

• Record Type: Journal Article
• Authors: Kwong, Jeffrey C.; Pereira, Jennifer A.; Quach, Susan; Pellizzari, Rosana; Dusome, Edwina; Russell, Margaret L.; Hamid, Jemila S.; Feinberg, Yael; Winter, Anne-Luise; Gubbay, Jonathan B.; Sirtonski, Brittany; Moher, Deanna; Sider, Doug; Finkelstein, Michael; Loeb, Mark; for the Public Health Agency of Canada/Canadian Institutes of Health Research Influenza Research Network (PCIRN) Program Delivery and Evaluation Group, 1
• Is Part Of: Vaccine. Volume 33:Issue 38(2015)
• Page Start: 4910
• Page End: 4915
• Publication Date: 2015-09-11
• Subjects: Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2015.07.044
• Languages: English
• ISSNs: 0264-410X

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <title id="sect0010">Background</title> <p id="spar0005">Children are key drivers of influenza transmission. Vaccinating school age children decreases influenza in the community.</p> </sec> <sec> <title id="sect0015">Objective</title> <p id="spar0010">To pilot-test the methods for a future trial to compare the direct and indirect benefits of inactivated influenza vaccine (IIV) vs. live attenuated influenza vaccine (LAIV) in preventing influenza infection.</p> </sec> <sec> <title id="sect0020">Methods</title> <p id="spar0015">During the 2013–14 influenza vaccination campaign, we piloted an open-label cluster randomized trial involving 10 elementary schools in Peterborough, Ontario, Canada. We randomized schools on a 1:1 basis to have students receive IIV or LAIV. We invited a subset of vaccinated students and their households to participate in a surveillance sub-study, which involved completing daily symptom diaries during influenza season and collecting mid-turbinate swabs from symptomatic individuals to detect influenza infection. The main outcome measure was confirmed influenza infection using a real-time reverse transcriptase polymerase chain reaction (PCR) assay.</p> </sec> <sec> <title id="sect0025">Results</title> <p id="spar0020">One hundred and nineteen households (166 students and 293 household members) participated. During 15 weeks of surveillance, we detected 22 episodes of PCR-confirmed influenza (21 influenza A/H1N1 and 1 influenza B). The incidence of influenza per 1000 person-days was 1.24 (95% CI, 0.40–2.89) for IIV-vaccinated students, compared to 0.13 (95% CI, 0.003–0.72) for LAIV-vaccinated students; the incidence rate ratio was 0.10 (95% CI, 0.002–0.94). Similarly, the incidence of influenza per 1000 person-days was 1.33 (95% CI, 0.64–2.44) for IIV household members, compared to 0.47 (95% CI, 0.17–1.03) for LAIV household members; the incidence rate ratio was 0.36 (95% CI, 0.11–1.08). The overall incidence rate ratio (combining students and household members) was 0.27 (95% CI, 0.09–0.69).</p> </sec> <sec> <title id="sect0030">Conclusions</title> <p id="spar0025">Household surveillance involving participant monitoring and reporting of symptoms and self-collection of mid-turbinate swabs is feasible. A larger study is required to validate the suggestion that vaccinating children with LAIV might confer more protection against influenza for both children and their household contacts, compared to IIV.</p> <p id="spar0030">Trial registration: ClinicalTrials.gov <ext-link ext-link-type="unknown" id="intr0005" xlink:type="simple" xlink:href="ctgov:NCT01995851" xmlns:xlink="http://www.w3.org/1999/xlink">NCT01995851</ext-link>.</p> </sec> </abstract>