WHO and FDA strengthen vaccine for 2018-19 season to target season’s No. 1 threat: H3N2
Even a flu vaccine can get the flu.
Overwhelmed by an unexpected surge by H3N2 strains, the flu shot wasn’t itself last season. With the disturbing numbers on the 2017-18 cold and flu season in front of them, the World Health Organization received the message loud and clear: The Northern Hemisphere’s current flu vaccine isn’t working.
As anyone who weathered influenza during one of the most brutal U.S. cold and flu seasons in decades can tell you, the current vaccine isn’t strong enough. The U.S. Centers for Disease Controls’ study found the 2017 vaccine delivered an only 36 percent effectiveness rate. That, coupled with the WHO’s recommendation, led the U.S. Food and Drug Administration to revise the Influenza A strains included this year’s flu shot. The main strain of H3N2, the devastating strain that caused the majority of flu-related illnesses last season, is included, along with H1N1. This year’s vaccine also targets two common B strains. Production has already begin on the 150 million doses of the FDA’s revamped vaccine.
Here’s this year’s American flu shot composition:
- A/Michigan/45/2015 (H1N1) pdm09-like virus
- A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus
- B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage)
- B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage
The goal is to make this year’s shot much more effective than last year’s shot, which recorded one of the weakest influenza prevention rates in American history.
Last year “was a bad flu year,” said U.S. FDA voting member Jack Bennick.
Was it ever: The CDC reports 177 influenza-associated pediatric deaths alone, while Fortune noted influenza-related deaths averaged 4,000 per week. The flu reached widespread levels in 48 of 50 states and 32 reported high flu activity with record-breaking hospitalizations. The Iowa Department of Public Health reported 271 influenza-related deaths in the Hawkeye State alone. H3N2 cases surged, something the WHO’s seasonal research and data hadn’t foreseen. The egg-based shot prevented only 25 percent of H3N2 cases. U.S. Pharmacist.com called last year’s vaccine “notoriously ineffective.”
“We have a lot to learn still about influenza,” Anne Schuchat, acting director for the CDC, told Fortune. “It’s a wakeup call about how severe influenza can be, and why we can never let down our guard.”
Some industry expects are calling for the FDC to move away from egg-based vaccine production, which they say is especially ineffective against H3N2. Clinical Infectious Diseases is forecasting the 2018-19 flu shot to be only 20 percent effective against H3N2.
“The vaccine has been changed for 2018-19, but unfortunately it still contains two critical mutations that arise from the egg-based vaccine production process,” said CID study author Michael Deem, professor of biochemical and genetic engineering at Rice University. “Our study found that these same mutations halved the efficiency of flu vaccines in the past two seasons, and we expect they will lower the efficacy of the next vaccine in a similar manner.”
Still, the vaccine remains our best defense against the flu. A strong 2018 flu shot greatly increases our chances of developing flu-related illnesses. The CDC reminds us all to always be vigilant in our personal hand hygiene and take smart measures to protect ourselves, family, friends, neighbors and coworkers from one of America’s greatest public health threats.
“These (2017-18 influenza season) deaths are a somber reminder of the importance of flu vaccination and the potential seriousness of the flu,” the CDC notes.