During week 7
ending February 17, 2018, the Centers for Disease Control and Prevention (CDC) reported fewer states experiencing high flu activity compared with the previous week
. In addition, the percentage of outpatient visits reported for influenza-like illness declined for the second week in a row, from 7.5% during week 6 to 6.4%. While widespread flu activity continues in all states but Hawaii and Oregon, a second wave of flu could still hit the country this season; however, CDC officials have said that peak flu activity
may be over.
After the CDC reported just 36% overall flu vaccine effectiveness
in its interim estimates for the 2017-2018 flu season, US Food and Drug Administration (FDA) commissioner Scott Gottlieb, MD, released a statement
on February 26, 2018 regarding the FDA’s ongoing effort to improve the vaccine’s effectiveness. On the issue of the vaccine’s low rate of 25% effectiveness overall against influenza A (H3N2), which has predominated this difficult flu season, Dr. Gottlieb noted that the vaccine was actually 51% effective against H3N2 in children ages 6 months to 8 years.
“There are a number of theories on why this season’s vaccines produced reduced effectiveness against H3N2. We’re taking steps to investigate each of these potential causes, rule out possible reasons for the variation in effectiveness and improve vaccine efficacy against H3N2,” wrote Dr. Gottlieb. “We don’t think it was a question of getting the particular H3N2 strain wrong when we set out to produce this season’s flu vaccines. Although adapting circulating virus strains for manufacture can lead to differences between the circulating strain and the one used for manufacturing that could affect effectiveness, so far, the data we have suggests that the viruses provided by reference laboratories to manufacturers to make this year’s vaccines do reasonably match the circulating flu strains that are causing most of the illnesses, including H3N2.”
Still, looking ahead to the 2018-2019 flu season, the World Health Organization (WHO) recently announced its recommendations
to change 2 of the 4 vaccine components, including the H3N2 and the influenza B Victoria lineage components. The new H3N2 vaccine strain will be A/Singapore/INFIMH-16-0019/2016, though public health experts worry that low vaccine effectiveness will persist as long as the H3N2 components continue to be egg-grown and prone to mutation
. Dr. Gottlieb noted in a recent tweet
that the FDA is reviewing improved flu vaccine efficacy in cell-based vaccines, and how this may impact decisions regarding next season’s flu vaccine components in the United States.
Meanwhile, a group of US Senators released a bill
proposal on February 15, 2018, in support of more comprehensive research on the development of a universal flu vaccine. Dubbed the Flu Vaccine Act, the bill, introduced by Ed Markey (D-Mass.), aims to invest $1 billion dollars over the next 5 years, allocating $200 million each year from 2019 through 2023 to the National Institutes of Health (NIH). In 2017, the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) spent $64 million on universal flu vaccine research.
“America’s scientists and clinicians are gold medalists in health and disease research, and is it is up to the United States to lead the world in the response to the flu,” said Senator Markey in a recent press release
. “We must enhance our ability to predict the right strain for the next season, produce a more optimal vaccine, and protect all Americans against all strains of this virus. The Flu Vaccine Act will help provide dedicated, consistent resources so that we can perform the basic science research necessary to improve upon our current vaccine and ultimately develop a universal one.”
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