NASA via Getty Images
NASA astronaut Scott Kelly gives himself a flu shot for an ongoing study on the human immune system September 24, 2015 in space.
- Flu season is approaching in the US and clinics are opening up to provide shots or a nasal mist for protection.
- The flu vaccine has been updated this year to combat new strains of the virus, and experts think it may perform better than last year's against some nasty versions.
- Even if a flu vaccine doesn't prevent you from getting the flu, it can make the illness less severe if you do get it.
Flu season is fast approaching in the US, and with it, a new flu vaccine is here.
After last year's shot performed so poorly, proving itself only 25% effective against some of the nastiest strains of the flu, infectious disease experts and drugmakers have reformulated the 2018-2019 vaccine. Although it's still early in the season, flu experts are hopeful about the new formula.
"What we hope is that it's going to be a better match to what's circulating," doctor Richard Webby, an infectious disease expert at St Jude Children's Research Hospital, told Business Insider.
Webby is part of the World Health Organization team that decides how the vaccine gets made each year, and which flu strains drug manufacturers will target for protection.
He says it's still too early to tell exactly how well this year's vaccine - which comes in both a shot and a mist - will pair up with the deluge of flu bugs that will better circulate in cooler, drier winter air. But there are already a few promising signs that this year's season might not be as bad as the last, and that this year's shot will better protect us from some of the worst cases of flu out there.
The new flu shot has two key difference from last year's vaccine
The formulation has been changed in two key ways: the nasty H3N2 strain that sickened many people last year has been updated, and the influenza B virus targeted for protection in the vaccine has been changed, too. So far, the revamped vaccines look promising.
"It appears that the virus is doing a little better job, if we look at what's gone on in the southern hemisphere season," Webby said.
Down south in Australia, for example, it's been a fairly mild flu season, with flu activity circulating at "low" levels, according to the Australian Department of Health. That may not perfectly translate to an equally mild flu season up north, but what Webby's seen so far suggests that the shot is also combatting the flu better than it did last year.
Drugmakers have been working since February to develop the new vaccine for this season's flu.
"Designing the vaccine takes a lot of effort and a lot of experimentation," Eva Lee, a mathematician and computational scientist who studies how flu viruses change and mutate at Georgia Tech, told Business Insider. "It takes about six months to really get the vaccine in good shape," she said.
During that time, most flu shots are grown in chicken eggs, the same way they've been manufactured for more than 70 years. Studies show it's perfectly safe for kids with egg allergies to receive these flu shots. The flu mist, a nasal spray, is also made in eggs.
One of the difficulties of designing a good flu shot this way is that manufacturers are dealing with a tough-to-control virus. As it is grown in the egg, it changes a bit. Meanwhile, the flu bug that's circulating in the population and sickening people is mutating and changing, too.
"That is really the chicken and egg catch," Lee said.
Webby agrees, adding that, "the flu shot is a great public health tool, but it's certainly not the best vaccine we have."
Even if the shot doesn't prevent the flu, it can make the illness milder
Despite its imperfections, The Centers for Disease Control and Prevention (CDC) estimates the flu vaccine can prevent a number of illnesses. During the 2015-2016 season, the CDC estimated that the vaccine prevented about 5 million flu cases in the US, and another 71,000 hospitalizations. It doesn't matter much whether you mist or you poke, Webby said, both methods provide a similar dose of protection.
There are some more potent versions of the flu vaccine available for elderly adults, who are some of the most at-risk of catching a deadlier flu.
In addition to lowering your chances of contracting a flu bug, the shot can also make the illness milder, if you do catch it. Finally, getting your flu shot can contribute to what's called "herd immunity" - fewer cases of the flu circulating in the population helps protect vulnerable people from getting sick, including the elderly, children, and individuals with certain allergies who can't get the vaccine. It takes about two weeks from vaccination for flu antibodies to fully build up in the body.
A flu shot can come with mild side effects, including soreness, low-grade fever, and muscle aches. But that's clearly better than coming down with a full-blown flu, which can knock you out for over a week.
If you're wondering where flu shots are available near you, the CDC has the following flu vaccine finder, searchable by zip code.