• The World Health Organization found that the flu vaccine may be a mismatch for this year’s flu strain in the United States.
  • Flu season ramps up in October and usually peaks around February.
  • Even a mismatched flu vaccine is better than nothing, so experts say you still need your flu shot.

We are just a few weeks away from flu season, which means now’s the time to get vaccinated to protect yourself against influenza.

The shot is, after all, your best bet at avoiding the flu.

But early reports from the World Health Organization (WHO) suggest this year’s shot might not be the most effective. Two of the strains that just struck the Southern Hemisphere, and then predictably may move north, aren’t included in the new vaccine.

However, that doesn’t mean the shot’s useless.

It’s still too soon to know exactly which strains will pop up this winter, and even if the shot is off the mark and fails to cover the strains likely to hit the United States this year, health experts say you should still plan to get vaccinated.

“It is hard to predict right now how effective the vaccine will be in the U.S. Even partial protection from influenza is much better than no protection,” Dr. Eric A. Weiss, an emergency medicine physician at Stanford Health Care, told Healthline.

Formulating the flu vaccine is a tricky business, according to Dr. David Cutler, a family medicine physician at Providence Saint John’s Health Center in Santa Monica, California.

Twice a year, flu experts meet at WHO to prepare the next year’s vaccine. During these meetings, the experts review which strains — Type A H1N1, Type A H3N2, and Type B influenza — recently circulated around the world and which ones are likely to pick up traction.

Based on those patterns and predictions, which aren’t a guarantee but rather an educated guess, a new flu vaccine is designed. It’s made up of three or four strains, which are considered the most likely to circulate in a given year.

“These virus strains vary quite rapidly season to season and even within a given season. So when experts meet twice a year to prepare the next year’s vaccine they need to use intuition, guesswork, and luck to choose the most likely candidates for the vaccine,” Cutler said.

The reason experts are concerned about this year’s vaccine boils down to the type of flu activity that recently took place in the Southern Hemisphere.

The strains that dominated the Southern Hemisphere’s winter — and are therefore likely to come to the United States — don’t match some of the strains included in our vaccine.

As Cutler puts it, “this past winter in the Southern Hemisphere (July to September) the most common strains of Type A H3N2 did not match the strain used in our current vaccine. However, the Type A H1N1 and Type B does match.”

That said, just because the shot seems to be a mismatch, does not mean it actually is. There are a few different ways the flu season could go, experts say.

The strains the United States sees could vary from the ones that affected the Southern Hemisphere, Cutler said. Furthermore, the Southern Hemisphere strains could undergo subtle genetic variation and start changing.

“There are four types of influenza viruses and every year, different strains of these viruses circulate and mutate. The H3N2 is a pesky virus to predict and to contain because it is very good at mutating and changing its proteins that vaccines target,” Weiss said.

All things considered, it’s important to get vaccinated.

The flu vaccine is never a 100 percent guarantee you won’t get sick, but even so, it can drastically lower your chances of falling ill. And even if you do get the flu, you’ll likely experience a milder symptoms if you’ve been vaccinated.

“If the vaccine is not a perfect match for the strains of influenza in circulation this winter, the vaccine may still prevent severe complications, mitigate the extent of illness, and prevent hospitalizations and deaths. Vaccines carry little risk and the potential benefits far outweigh the risks,” Weiss said.

It takes about 2 weeks for the flu shot to start working. The Centers for Disease Control and Prevention recommends getting vaccinated by late October, before flu season really kicks in, so your body can create enough antibodies to protect itself against the flu.

On top of getting vaccinated, be sure to wash your hands frequently and keep your health in check by eating well, staying hydrated, exercising, and adhering to your prescribed medications, says Cutler.

As flu season picks up, stay about 6 feet away from sick people, especially those who are coughing and sneezing, and try to sanitize public touch screens before using them as they’re known hotspots for bacteria.

Early reports of flu activity in the Southern Hemisphere suggest this year’s flu vaccine might have missed the mark. Two of the strains that dominated the Southern Hemisphere, and are therefore likely to strike to the United States, are not included in this year’s shot.

Still, it’s too soon to know exactly what this year’s flu season will look like, and health experts say it’s crucial to get vaccinated as it’s your best bet at avoiding the flu.