The flu vaccine is about to get a lot less generous. A U.S. Food and Drug Administration advisory panel on Friday unanimously recommended that manufacturers cut back by more than one-third on the flu vaccine they’ll produce next year. Some estimates suggest that if the change is finalized, global supply of flu vaccine will drop 20 percent. Influenza killed 44,000 Americans last year, in flu season. So the need for a more effective vaccine is great.
The three vaccines on the market now protect against three different flu strains. The new recommendation to lower the number of different strains is aimed at protecting against the flu strain that causes the most deaths each year. Typically, the six strains of virus are kept to be manufactured into two or three vaccines that are primarily made from chicken eggs and those that rely on T cells to protect against the disease, but the new recommendation could put the added pressure on T cell vaccinations to produce more effectiveness.
Scientists from the F.D.A. had been debating the vaccine recommendation, which affects manufacturers like Novartis, Sanofi, GlaxoSmithKline and others, since last year.
The recommendations, for the 2018-2019 flu season, would cut the number of strains in the vaccines to two from three, and only to strains that cause 50 percent or more disease deaths annually. “Last year, the H3N2 strain accounted for the most illnesses and deaths in the United States,” F.D.A. Commissioner Scott Gottlieb said, and it remains unclear which virus will dominate the flu season, “but we know that the increase in influenza deaths in 2017-2018 was affected by more strains spreading simultaneously than in years past.”
As Gottlieb emphasized, other vaccines being developed for the upcoming flu season also must be tested against a more limited set of strains. If studies are successful, the possible single-strain vaccines will be given for the first time in an attempt to produce the best vaccine for a year.
One scientist who studies flu vaccines said the dwindling stocks are driven by the virus itself. This autumn, for the first time in nearly a decade, the U.S. has seen a multi-strain U.S. flu season, and that information gets passed along to people most prone to getting the virus, like children and the elderly. “We saw what happened last year. We saw the H3N2 influenza that triggered a lot of deaths,” microbiologist Robert Tauxe, of the Centers for Disease Control and Prevention, said.
Gottlieb said no one has a clear answer as to how this new generation of flu strains will develop. “We don’t know why these strains were once predominant but not this year,” Gottlieb said. “We see less protection with less circulating strains.”
“But our thinking around influenza,” Gottlieb said, “is that one disease can reach every ZIP code.”
Flu clinics will not be forced to accept the panel’s recommendation. If the recommendation is finalized, patients could seek vaccines from clinics in the area or order them online. But there could be shortages in the future.
So far, there are no signs that large quantities of the vaccines might not be available. And experts say those who have more options than most will still want the vaccine, because they should: it’s about saving lives. But even for those who aren’t as serious about their health, getting a flu shot is worth it. According to the Centers for Disease Control and Prevention, a flu shot is the single greatest protection against influenza. For young, healthy, healthy-minded adults, they may even boost their lifespan by about three months, said Stephen Blumberg, an associate professor of epidemiology at Harvard Medical School.
So even if the FDA approves the reduced amount of strains, the actual flu strains will still be hard to predict. This season, things are looking better. Over the weekend, all seven flu strains tested by the U.S. Centers for Disease Control and Prevention were common. That was better than last year, when only three strains tested were common.
Still, it took a week or two to show up in vaccines. This year will be different: while some experts were predicting too many viruses, others were worried that this year’s vaccine was not strong enough, and influenza typically peaks in February, so flu season won’t start for another two months.