How effective is the 2018 influenza vaccine?

The 2018-2019 influenza season has officially arrived, the Food and Drug Administration announced this week. And after the flu last year, 80,000 people were killed – the largest number of victims of the American flu in 40 years – and many wonder if the flu vaccine is effective.

The short answer: no one really knows it.

The long answer: This year's influenza vaccine looks promising – so far.

According to the FDA, the effectiveness of the flu vaccine varies every year because there are many influenza strains that spread each season. Each vaccine is formulated to target three or four strains most likely to circulate each year, but determining what type of vaccine to include in the seasonal flu vaccine is an educated guessing game.

And although the flu shot does not become a topic of conversation until September for most people, researchers from several federal agencies spend the entire year studying the flu season and at the same time. Prepare there.

The FDA, the World Health Organization and the Centers for Disease Control and Prevention annually review global data to determine which strains to include in the vaccine, a decision that must be made months before the next influenza season. This year's influenza vaccine strains were chosen in March.

"One of the challenges of fighting the flu is that viruses can change their genetic makeup quickly, not only between flu seasons, but also during a single season," said the commissioner. Scott Gottlieb, MD of the FDA. "As a result, the seasonal flu vaccine must be evaluated annually to see if its composition needs to be adjusted."

And that's what researchers think is one of the reasons why last year's flu season was so deadly – the virus mutated.

"We have guessed the common tensions that dominated last year's flu season," Gottlieb said. "It is now believed that the reason the vaccine was not so protective is that the influenza strain used to make the vaccine has undergone a very subtle mutation during the development process."

Those who received the influenza vaccine in 2017 still developed antibodies to ward off the virus, but because of the slight changes that the virus had already undergone, these antibodies were not sufficient for the mutated virus.

"This is not the first time that vaccine strains have deviated significantly from the influenza strain that eventually circulates during the flu season," said Gottlieb. "But we learned a lot from these extremely regrettable incidents. And we have improved our scientific methods to reduce the chances of this happening again. "

Improvements to the 2018 influenza vaccine include the replacement of two of last year's influenza strains with potentially better matches. And, until now, this new vaccine appears to be on the right track.

According to Gottlieb, the 2018 influenza vaccine should be effective based on current influenza characteristics in the southern hemisphere.

So, should you get the flu shot this year? Yes. The FDA points out that the seasonal vaccine is still the most effective way to fight the flu, not only for yourself, but for those around you as well.

Last year, most children who died of the flu had not been vaccinated, the agency said, adding that even if a person had the flu, a flu shot could lessen the flu.

The flu vaccine is recommended by the FDA and CDC for people aged 6 months and older, especially those in high-risk groups: pregnant women, the elderly and young children.