For example, in the UK all healthcare workers involved in patient care are recommended to receive the seasonal flu vaccine, and were also recommended to be vaccinated against the,In a 2010 survey of United States healthcare workers, 63.5% reported that they received the flu vaccine during the 2010–11 season, an increase from 61.9% reported the previous season. In addition, some areas experienced local shortages of.The composition of virus vaccines for use in the 2018 Southern Hemisphere influenza season recommended by the World Health Organization on September 28, 2017 was:The WHO recommended that quadrivalent vaccines containing two influenza B viruses should contain the above three viruses and a B/Brisbane/60/2008-like virus.The composition of virus vaccines for use in the 2018–2019 Northern Hemisphere influenza season recommended by the World Health Organization on February 22, 2018 was:The WHO recommended that trivalent vaccines use as their influenza B virus a B/Colorado/06/2017-like virus of the B/Victoria/2/87-lineage.The composition of virus vaccines for use in the United States for the 2018–2019 Northern Hemisphere influenza season recommended by the Food and Drug Administration on March 1, 2018, was:The committee also recommended that quadrivalent influenza vaccines contain the above three strains and the following additional B strain:The composition of virus vaccines for use in the 2019 Southern Hemisphere influenza season recommended by the World Health Organization in September 2018 was:The composition of virus vaccines for use in the 2019–2020 Northern Hemisphere influenza season recommended by the World Health Organization on March 21, 2019 was:The composition of virus vaccines for use in the 2020–2021 Northern Hemisphere influenza season recommended by the World Health Organization on February 28, 2020 is.The WHO recommends that trivalent vaccines use as their influenza B virus a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.The composition of virus vaccines for use in the United States for the 2019–2020 Northern Hemisphere influenza season recommended by the Food and Drug Administration (FDA) on March 22, 2019, was:The Vaccines and Related Biological Products Advisory Committee (VRBPAC) of the.The committee recommended that the quadrivalent formulation of cell- or recombinant-based influenza vaccines for the US 2020–2021 influenza season contain the following:For trivalent influenza vaccines for use in the US for the 2020–2021 influenza season, depending on the manufacturing method of the vaccine, the committee recommended that the A(H1N1)pdm09, A(H3N2) and B/Victoria lineage viruses recommended above for the quadrivalent vaccines be used.The composition of virus vaccines for use in the European Union for the 2019–2020 Northern Hemisphere influenza season recommended by the European Medicines Agency on May 15, 2019, is:For vaccine manufacturers considering the use of a B/Yamagata/16/88 virus lineage vaccine virus in quadrivalent vaccines containing two influenza B viruses, a B/Phuket/3073/2013-like virus in addition to the strains mentioned above is considered appropriate.The composition of virus vaccines for use in the European Union for the 2020–2021 Northern Hemisphere influenza season recommended by the European Medicines Agency on April 1, 2020, is:Egg-based or live attenuated trivalent vaccines should contain:Cell-based trivalent vaccines should contain:A B/Phuket/3073/2013-like virus is recommended in addition to the strains mentioned above for the quadrivalent vaccines.The composition of virus vaccines for use in the 2020 Southern Hemisphere influenza season influenza season recommended by the World Health Organization in September 2019 was:The WHO recommended that trivalent vaccines use as their influenza B virus a B/Washington/02/2019-like (B/Victoria lineage) virus.Vaccines are used in both humans and nonhumans.

New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes. The best time to have a flu vaccine is in the autumn before flu starts circulating. and Plotkin, S.A. "A short history of vaccination.