Temporal patterns of influenza A and B in tropical and temperate countries: What are the lessons for influenza vaccination?

Global Influenza B Study

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)

Abstract

Introduction: Determining the optimal time to vaccinate is important for influenza vaccination programmes. Here, we assessed the temporal characteristics of influenza epidemics in the Northern and Southern hemispheres and in the tropics, and discuss their implications for vaccination programmes. Methods: This was a retrospective analysis of surveillance data between 2000 and 2014 from the Global Influenza B Study database. The seasonal peak of influenza was defined as the week with the most reported cases (overall, A, and B) in the season. The duration of seasonal activity was assessed using the maximum proportion of influenza cases during three consecutive months and the minimum number of months with ≥80% of cases in the season. We also assessed whether co-circulation of A and B virus types affected the duration of influenza epidemics. Results: 212 influenza seasons and 571,907 cases were included from 30 countries. In tropical countries, the seasonal influenza activity lasted longer and the peaks of influenza A and B coincided less frequently than in temperate countries. Temporal characteristics of influenza epidemics were heterogeneous in the tropics, with distinct seasonal epidemics observed only in some countries. Seasons with co-circulation of influenza A and B were longer than influenza A seasons, especially in the tropics. Discussion: Our findings show that influenza seasonality is less well defined in the tropics than in temperate regions. This has important implications for vaccination programmes in these countries. High-quality influenza surveillance systems are needed in the tropics to enable decisions about when to vaccinate.

Original languageEnglish
Article numbere0152310
JournalPLoS ONE
Volume11
Issue number3
DOIs
Publication statusPublished - 1 Mar 2016

Bibliographical note

Funding Information:
The Global Influenza B Study was supported by an unrestricted grant from Sanofi Pasteur; this does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. The authors have no other potential competing interests to declare.

Publisher Copyright:
© 2016, Public Library of Science. All rights reserved. This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Fingerprint

Dive into the research topics of 'Temporal patterns of influenza A and B in tropical and temperate countries: What are the lessons for influenza vaccination?'. Together they form a unique fingerprint.

Cite this