WHO Regional Office for Europe recommendations on influenza vaccination during the 2014/2015 winter season: 01.09.2014

WHO Regional Office for Europe recommendations on influenza vaccination during the 2014/2015 winter season September 2014 Address requests about publications of the WHO Regional Office for Europe to: Publications WHO Regional Office for Europe Marmorvej 51 DK-2100 Copenhagen Ø, Denmark Alternatively, complete an online request form for documentation, health information, or for permission to quote or translate, on the Regional Office website (http://www.euro.who.int/pubrequest). © World Health Organization 2014 All rights reserved. The Regional Office for Europe of the World Health Organization welcomes requests for permission to reproduce or translate its publications, in part or in full. 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However, the published material is being distributed without warranty of any kind, either express or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall the World Health Organization be liable for damages arising from its use. The views expressed by authors, editors, or expert groups do not necessarily represent the decisions or the stated policy of the World Health Organization. WHO Regional Office for Europe recommendations on influenza vaccination during the 2014/2015 winter season Influenza infection is usually mild and uncomplicated, but may occasionally cause severe disease, particularly among the elderly, pregnant women, very young children and persons with underlying medical conditions. Seasonal influenza vaccination is safe and the most effective means of preventing infection and severe outcomes caused by influenza viruses. In the northern hemisphere, influenza usually causes annual epidemics during autumn and winter. Due to the influenza virus’ continuous genetic and antigenic changes, vaccination against influenza is recommended every year before the season begins. WHO annually recommends a vaccine composition for the northern hemisphere in February, which targets those strains expected to be the most common in the coming season. COMPOSITION OF INFLUENZA VACCINES FOR 2014-2015 The virus strains recommended for inclusion in the trivalent seasonal influenza vaccine in the northern hemisphere 2014/2015 winter season are the same as those used in northern hemisphere for 2013/2014 influenza season and include:1,2  A/California/7/2009 (H1N1)pdm09-like virus;  A/Texas/50/2012 (H3N2)-like virus;  B/Massachusetts/2/2012-like virus In quadrivalent vaccines containing two influenza B viruses, it is recommended to include the above three viruses plus a B/Brisbane/60/2008-like virus. At the February 2014 vaccine composition meeting A(H1N1)pdm09, A(H3N2) and influenza B viruses of the B/Victoria/2/87 and the B/Yamagata/16/88 lineages were predicted to co-circulate as in the previous seasons in the northern hemisphere. However, analysis of influenza viruses circulating globally since February 2014 has shown that an increasing proportion of A(H3N2) and influenza B Yamagata lineage viruses have undergone antigenic drift.3 This prompted a change in recommendations for the composition of influenza vaccines for use in the 2015 southern hemisphere season compared to those recommended for the northern hemisphere 2014-2015 influenza seasons published on 25 September 2014. 4 Should these new virus strains circulate in the European Region in the upcoming influenza season the current 1 Recommended composition of influenza virus vaccines for use in the 2014-2015 northern hemisphere influenza season; http://www.who.int/influenza/vaccines/virus/recommendations/201402_recommendation.pdf?ua=1 2 Questions and Answers. Recommended composition of influenza virus vaccines for use in the northern hemisphere 2014-15 influenza season and development of candidate vaccine viruses for pandemic preparedness http://www.who.int/influenza/vaccines/virus/recommendations/201402_qanda_recommendation.pdf?ua=1 3 WHO Consultation and Information Meeting on the Composition of Influenza Virus Vaccines for the Southern Hemisphere 2015; http://www.who.int/influenza/vaccines/virus/recommendations/consultation201409/en/ 4Recommended composition of trivalent vaccines for use in the 2015 influenza season (southern hemisphere winter): A/California/7/2009 (H1N1)pdm09-like virus; A/Switzerland/9715293/2013 (H3N2)-like virus; and B/Phuket/3073/2013-like virus. vaccine composition recommended for northern hemisphere is expected to provide cross protection against A(H3N2) and influenza B viruses, albeit at a reduced level. WHO/Europe will continue to monitor global influenza virus circulation and will provide updated recommendations as needed. RECOMMENDATED TARGET GROUPS FOR INFLUENZA VACCINATION Seasonal vaccination against influenza is safe and remains the single best way to prevent influenza. Vaccination can benefit all age groups, but is especially important for people at higher risk of serious influenza complications. Specific population groups may be targeted for vaccination depending on the objectives of the national vaccination programme, documented vaccine effectiveness, access to vaccine, and the ability to implement vaccination campaigns in the targeted groups. The priority groups for immunization listed below are drawn from the 2012 WHO position paper on influenza vaccines.5 Priority groups that should be considered for immunization include:  pregnant women;  individuals >6 months with chronic heart or lung diseases, metabolic or renal disease, chronic liver disease, chronic neurological conditions or immunodeficiencies;  elderly persons over a nationally defined age limit, irrespective of other risk factors;  residents of long-term care facilities for older persons and the disabled;  children aged 6–59 months;  health care workers including those who work in facilities that care for the elderly or persons with disabilities. Further information Questions and Answers for health professionals on seasonal inactivated influenza vaccines. http://www.euro.who.int/__data/assets/pdf_file/0005/155633/Q-and- A_on_seasonal_inactivated_influenza_vaccines_21-12-2011_FINAL.pdf Information sheets on reaction rates of seasonal influenza vaccines (available in English and Russian) http://www.who.int/vaccine_safety/initiative/tools/vaccinfosheets/en/ Health conditions for travellers to Saudi Arabia for the pilgrimage to Mecca (Hajj), 2014. Wkly Epidemiol Rec 2014;89(32/33):357-60. http://www.who.int/wer/2011/wer8639.pdf?ua=1 5 Seasonal influenza vaccine, Weekly Epidemiological Record: 2012 (21); 87, 201–16 (www.who.int/wer/2012/wer8721.pdf)