U.K.-based drugmaker GlaxoSmithKline announced Thursday that it has started shipping its Fluarix flu vaccine to U.S. pharmacies and healthcare providers. Last year's ineffective vaccinations are top of mind as drugmakers and physicians hope this year's vaccine formula is on target.
More than half of the influenza cases reported during the 2014-2015 flu season came from a mutated virus strain that the vaccine didn't protect against. Last year, flu vaccines from various manufacturers had an effectiveness rate of just 23%, while in other recent years, the vaccine has had an efficacy rate of 47% to 60%, according to the Centers for Disease Control and Prevention.
GSK and other vaccine manufacturers say it's hard to predict how this year's virus will play out.
The World Health Organization and the Food and Drug Administration identify flu strains in February, so that manufacturers have time to produce and test the vaccine over five months before the flu season officially begins. This year, vaccine makers were advised to swap out two strains to account for last year's “drifting virus.”
When asked whether GSK is confident they've got the right mix this year, Dr. Leonard Friedland, the company's director of scientific affairs and public health, said he stands behind the company's vaccines.
“We're confident that the best science is being applied to choose the best strains to be in the vaccine,” Friedland said. “It's our job to produce a vaccine that's of the highest quality of safety and effectiveness for those strains.”
For the first time, GSK will only offer quadrivalent vaccines, which include four strains of the virus. The company claims that composition will give broader flu protection.
But a quadrivalent vaccine still doesn't mean patients will be protected against a mutation, said Dr. Chip Altman, head of medical affairs for drugmaker bioCSL, which recently started shipping out its trivalent vaccine. Efficacy depends on what strains are included in the vaccine, he said, noting that, despite including four strains, last year's quadrivalent vaccines didn't account for the virus' mutation.
Friedland said customers have asked for the quadrivalent vaccine, and insurance companies have offered reimbursement for it.
Even if the next flu season brings another mutation the scientific community hasn't planned for, the vaccine still plays an important role in taming the virus, said Dr. Nadia Qureshi, an assistant professor of pediatrics and pediatric infectious-disease specialist at the Loyola University School of Medicine in Maywood, Ill.
“Even if it is not 100% effective in completely preventing the flu, it definitely decreases the severity of the disease or the need for hospitalization,” Qureshi said.