A few things are new this season:

  • Flu vaccines are updated to better match viruses expected to be circulating in the United States.
    • The A(H1N1)pdm09 vaccine component was updated from an A/Michigan/45/2015 (H1N1)pdm09-like virus to an A/Brisbane/02/2018 (H1N1)pdm09-like virus.
    • The A(H3N2) vaccine component was updated from an A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus to an A/Kansas/14/2017 (H3N2)-like virus.
    • Both B/Victoria and B/Yamagata virus components from the 2018-2019 flu vaccine remain the same for the 2019-2020 flu vaccine.
  • All regular-dose flu shots will be quadrivalent. (No trivalent regular-dose flu shots will be available this season.)
  • All recombinant vaccine will be quadrivalent. (No trivalent recombinant vaccine will be available this season.)
  • All four of the vaccine viruses used to produce cell-grown flu vaccine will have been grown in cells, not eggs.
  • In January 2019, the U.S. Food and Drug Administration (FDA) approved a change in dose volume for Fluzone Quadrivalent, a quadrivalent inactivated influenza vaccine.
    • The change in dose volume affects children 6 through 35 months of age.
    • Previously, children in this age group were recommended to receive 0.25 milliliters of this vaccine per dose.
    • Children 6 through 35 months of age may now receive either 0.25 milliliters or 0.5 milliliters per dose.
    • There is no preference for one or the other dose volume for this age group. All persons 36 months (or 3 years) of age and older should receive 0.5 milliliters per dose.
  • In October 2018, FDA approved an expanded age indication for Afluria Quadrivalent, a quadrivalent inactivated influenza vaccine. Afluria Quadrivalent is now licensed for children 6 months of age and older. Children 6 months through 35 months of age should receive 0.25 milliliters for each dose. All persons 36 months (or 3 years) of age and older should receive 0.5 milliliters for each dose.
  • Baloxavir marboxil (trade name Xofluza®) is a new flu single-dose antiviral drug approved October 24, 2018 by FDA. Baloxavir is approved for the treatment of acute uncomplicated flu in people 12 years and older who have had flu symptoms for less than 48 hours. More information is available here: Influenza Antiviral Drug Baloxavir Marboxil.
  • For the 2019-2020 flu season, CDC is offering additional guidance on timing of flu vaccination for both adults and children.
    • Like last season, CDC and ACIP recommend that vaccination be offered by the end of October.
      • For this season, CDC and ACIP provided additional information on what might be considered vaccinating too early. “Vaccinating early – for example, in July or August –may lead to reduced protection against influenza later in the season, particularly among older adults.”
    • Children 6 months through 8 years of age who need 2 doses should receive their first dose as soon as possible after vaccine becomes available to allow the second dose (which must be administered at least 4 weeks later) to be received by the end of October.

 

Learn more about flu forecasting by visiting https://www.cdc.gov/flu/weekly/flusight/index.html.