What’s new this flu season?
A few things are new this season:
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Flu vaccines have been updated to better match circulating viruses [the B/Victoria component was changed and the influenza A(H3N2) component was updated].
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For the 2018-2019 season, the nasal spray flu vaccine (live attenuated influenza vaccine or “LAIV”) is again a recommended option for influenza vaccination of persons for whom it is otherwise appropriate. The nasal spray is approved for use in non-pregnant individuals, 2 to 49 years old. There is a precaution against the use of LAIV for people with certain underlying medical conditions. All LAIV will be quadrivalent (four-component).
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Most regular-dose egg-based flu shots will be quadrivalent.
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All recombinant vaccine will be quadrivalent. (No trivalent recombinant vaccine will be available this season.)
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Cell-grown flu vaccine will be quadrivalent. For this vaccine, the influenza A(H3N2) and both influenza B reference viruses will be cell-derived, and the influenza A(H1N1) will be egg-derived. All these reference viruses will be grown in cells to produce the components of Flucelvax.
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No intradermal flu vaccine will be available.
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The age recommendation for “Fluarix Quadrivalent” was changed from 3 years and older to 6 months and older after the annual recommendations were published last season to be consistent with Food and Drug Administration (FDA)-approved labeling.
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The age recommendation for Afluria Quadrivalent was changed from 18 years and older to 5 years and older after the annual recommendations were published last season to be consistent with Food and Drug Administration (FDA)-approved labeling.
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Baloxavir marboxil (trade name Xofluza®) is a new influenza single-dose antiviral drug approved October 24, 2018 by the Food and Drug Administration (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: Influenza Antiviral Drug Baloxavir Marboxil.
What viruses will the 2018-2019 flu vaccines protect against?
There are many different flu viruses and they are constantly changing. The composition of U.S. flu vaccines is reviewed annually and updated as needed to match circulating flu viruses. Flu vaccines protect against the three or four viruses (depending on vaccine) that research suggests will be most common. For 2018-2019, trivalent (three-component) vaccines are recommended to contain:
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A/Michigan/45/2015 (H1N1)pdm09-like virus
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A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus (updated)
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B/Colorado/06/2017-like (Victoria lineage) virus (updated)
Quadrivalent (four-component) vaccines, which protect against a second lineage of B viruses, are recommended to contain:
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the three recommended viruses above, plus B/Phuket/3073/2013-like (Yamagata lineage) virus
Copyright CDC January, 2021