The epidemiological signature of influenza B virus and its B/Victoria and B/Yamagata lineages in the 21st century

Saverio Caini*, Gabriela Kusznierz, Verònica Vera Garate, Sonam Wangchuk, Binay Thapa, Francisco José De Paula, Walquiria Aparecida Ferreira De Almeida, Richard Njouom, Rodrigo A. Fasce, Patricia Bustos, Luzhao Feng, Zhibin Peng, Jenny Lara Araya, Alfredo Bruno, Doménica De Mora, Mónica Jeannette Barahona De Gámez, Richard Pebody, Maria Zambon, Rocio Higueros, Rudevelinda RiveraHerman Kosasih, Maria Rita Castrucci, Antonino Bella, Hervé A. Kadjo, Coulibaly Daouda, Ainash Makusheva, Olga Bessonova, Sandra S. Chaves, Gideon O. Emukule, Jean Michel Heraud, Norosoa H. Razanajatovo, Amal Barakat, Fatima El Falaki, Adam Meijer, Gé A. Donker, Q. Sue Huang, Tim Wood, Angel Balmaseda, Rakhee Palekar, Brechla Moreno Arévalo, Ana Paula Rodrigues, Raquel Guiomar, Vernon Jian Ming Lee, Li Wei Ang, Cheryl Cohen, Florette Treurnicht, Alla Mironenko, Olha Holubka, Joseph Bresee, Lynnette Brammer, Mai T.Q. Le, Phuong V.M. Hoang, Clotilde El Guerche-Séblain, John Paget

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

95 Citations (Scopus)


We describe the epidemiological characteristics, pattern of circulation, and geographical distribution of influenza B viruses and its lineages using data from the Global Influenza B Study. We included over 1.8 million influenza cases occurred in thirty-one countries during 2000-2018. We calculated the proportion of cases caused by influenza B and its lineages; determined the timing of influenza A and B epidemics; compared the age distribution of B/ Victoria and B/Yamagata cases; and evaluated the frequency of lineage-level mismatch for the trivalent vaccine. The median proportion of influenza cases caused by influenza B virus was 23.4%, with a tendency (borderline statistical significance, p = 0.060) to be higher in tropical vs. temperate countries. Influenza B was the dominant virus type in about one every seven seasons. In temperate countries, influenza B epidemics occurred on average three weeks later than influenza A epidemics; no consistent pattern emerged in the tropics. The two B lineages caused a comparable proportion of influenza B cases globally, however the B/Yamagata was more frequent in temperate countries, and the B/Victoria in the tropics (p = 0.048). B/Yamagata patients were significantly older than B/Victoria patients in almost all countries. A lineage-level vaccine mismatch was observed in over 40% of seasons in temperate countries and in 30% of seasons in the tropics. The type B virus caused a substantial proportion of influenza infections globally in the 21st century, and its two virus lineages differed in terms of age and geographical distribution of patients. These findings will help inform health policy decisions aiming to reduce disease burden associated with seasonal influenza.

Original languageEnglish
Article numbere0222381
JournalPLoS ONE
Issue number9
Publication statusPublished - 1 Sept 2019

Bibliographical note

Publisher Copyright:
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.


Dive into the research topics of 'The epidemiological signature of influenza B virus and its B/Victoria and B/Yamagata lineages in the 21st century'. Together they form a unique fingerprint.

Cite this