Officials from the U.S. Centers for Disease Control and Prevention (CDC) announced that the formulations of the flu shot this year are a good match for the current viral strains circulating in the country.

The news comes as flu cases have risen drastically in recent weeks.

It’s estimated that up to 11% of Americans catch the flu virus each year — with some experiencing more severe symptoms and requiring hospitalization.

Vaccines are updated to protect against the viruses that research indicates will be most common during the upcoming flu season.

According toTrusted Source the CDC, the research includes looking at which flu strains are affecting people before the main flu season and how they are spreading.

Despite the potential for virus ‘mismatch’, the CDC announced this week that this year’s vaccine seemingly aligns with the circulating strains.

The vaccine targets more than just one type of flu virus. All flu vaccines in the United States are ‘quadrivalent’ vaccines, which means they protect against four different flu viruses.

The four viruses are:

• Influenza A(H1N1) virus
• Influenza A(H3N2) virus
• Two influenza B viruses

According to CDC dataTrusted Source, of the influenza A viruses seen in the US so far this year, 79% have been the A(H3N2) strain, while 21% have been A(H1N1).

In recent years, the flu shot has providedTrusted Source around 43% protection against disease.

However, year-to-year, that level has ranged widely: from 60% in the 2010-2011 flu season to 19% in the 2014-2015 flu season.

As the flu season progresses, experts will continue to get more information about the most common circulating strains.

Experts say the flu shot can also help lessen symptoms for people who end up developing the disease.

When formulating flu shots, experts look at countries in the southern hemisphere to see what strains are circulating during their winter.

When formulating flu shots, experts look at countries in the southern hemisphere to see what strains are circulating during their winter.

For instance, the CDC noted that, in Chile, where the flu season began far earlier than in most years in January, the primary strain circulating was a type of influenza A(H3N2) virus. The virus also started spreading earlier in the year than usual and resulted in more hospitalizations than during the 2020-21 flu season.

Numerous studies have explored how effectively flu vaccines protect against the virus. The CDC estimated that, during the 2019-20 flu season, vaccinations prevented around 7.5 million flu infections and 105,000 flu-related hospitalizations.

Meanwhile, in Chile earlier this year, vaccination was associate with a 49% reduced risk of hospitalization from the A(H3N2) flu virus — the most predominant type being transmitted at the time.

Furthermore, these actions have limited [our] exposure in the last few years to flu. As such, it’s expected that flu may be worse because of lower levels of circulating antibodies.

The government has stated everyone over the age of six months can get a flu shot, although in rare cases they are not advised for some individuals (such as those with certain allergies).