What’s the Buzz

When Does Flu Season Start, and is it Coming Back This Year?

flu season cartoon

Millions of Americans get the flu each year. You can get the flu at any time of the year, but it is more common during flu season. Since March 2020, the world has been dealing with the Covid-19 pandemic. As a result, the common flu has been the last thing on people’s minds. Interestingly, not only has the flu been out of mind, but it has also been out of sight. In the 2020-2021 flu season last year, the Centers for Disease Control (CDC) recorded just over 2,000 lab-confirmed influenza cases in the US. In a typical flu season, this number is 100 times higher. For example, in 2019-2020, the year before the pandemic began, there were around 200,000 lab-confirmed cases of the flu virus. (Notably, the actual number of people who got flu symptoms is estimated to be much higher​​—around 38 million in 2019-2020). Flu-related hospitalizations and deaths in 2020-2021 were some of the lowest ever recorded. 

This is all great news in terms of public health. But what are the predictions for flu season 2021-2022? What brought the common cold and flu cases down so drastically last year? Do you need to get the flu vaccination this year? Please continue reading to find out.

Is flu common this time of year?

The exact dates of the flu season in the United States are not fixed and change every year. However, flu season typically starts in the fall when temperatures begin to fall and ends when temperatures rise in the spring. This means a typical flu season in the US runs from October through April. This is also true for other countries such as Canada and Europe. 

Flu seasons in other countries may occur at different times of the year. For example, in countries in the Southern Hemisphere, such as Australia, South Africa, and Brazil, the flu season runs in the winter months: April through October (opposite to the US).

What months can you get the flu?

You can get the flu at any time of the year. However, flu activity usually picks up in October. Cases usually peak around November and remain high through February. Flu activity typically begins to decline in March. 

This means the flu season for 2021-2022 is right around the corner. The exact date cannot be predicted, but based on historical trends, cases are expected to rise in October and peak between November and February.

Is the flu going around in 2021?

As mentioned above, the 2020-2021 flu season (last year) was dramatically less severe than previous years. 

Before the pandemic started (2019-2020 season), the Centers for Disease Control and Prevention (CDC) estimated 38 million people got sick with flu symptoms (fever, watery eyes, nose running, etc.). There were 400,000 hospitalizations and 22,000 flu-related deaths in 2019-2020. Approximately 130,000 flu cases were recorded between September 2019 and January 2020. In contrast, the Centers for Disease Control and Prevention (CDC) logged only around 1,300 flu cases the subsequent year (after the pandemic began).

Does this mean we can expect another year of respite from respiratory viruses? No. Experts are warning that the flu virus could come back with a vengeance this fall (in the 2021-2022 flu season). There are several reasons for this fear. All the things that people did to reduce the spread of Covid-19, such as masking, washing hands, using hand sanitizer, social distancing, avoiding crowded places, and staying home when sick, also helped prevent illness and deaths from influenza infections during the pandemic. 

In the current 2021-2022 flu season, these protective factors may no longer be present. Pandemic fatigue, more and more people getting Covid-19 vaccinations, reduced masking and social distancing, and people going back to work this fall means that flu activity could be back at usual or higher levels. 

Experts fear we may see record numbers of influenza infections this flu season. This is because in the years that you don’t catch flu viruses, you still get exposed to them. This helps your body build immunity. The lack of exposure to respiratory viruses in the past year during the Covid-19 pandemic might make the population more susceptible to the flu virus when it comes back.

Who is at the highest risk of the flu in 2021?

Because there was so little flu activity last year, most people won’t have the boost of natural immunity, as noted above. Also, those who did not get a flu shot last flu season will have to depend on immunity developed two or more flu seasons ago. 

As always, older individuals (65 years and above) and children will be especially vulnerable to flu viruses in 2021-2022. Older adults because their immune system is not as robust. Children because they may not have been exposed to flu viruses before. In particular, young children who have stayed home throughout the Covid-19 pandemic and will now go to daycare for the first time will be at risk to get the flu, because it might be their first time getting exposed to the flu virus.

With that said, even healthy adults may be at increased risk this flu season due to a lack of exposure to flu viruses last year. This could mean longer illness duration, more severe flu symptoms, and more hospitalizations and deaths.

Should I get the flu shot this year? 

Vaccination helps prevent you from getting sick with the flu. It also reduces the risk of serious flu illness and complications like pneumonia, hospitalization, and death. Getting vaccinated for the flu not only protects you but also those around you, including young children, older individuals, and pregnant women who are particularly vulnerable to serious flu illness. For vulnerable individuals, the influenza vaccine can be life-saving. 

The CDC recommends getting the flu vaccine every year. The flu shot is recommended for everyone aged 6 months or older, including pregnant women. Flu vaccines are available as a flu shot or nasal spray. Each year, a new flu vaccine is developed to protect against the strain predicted to be most prevalent in the upcoming flu season. In the 2021-2022 flu season, the flu vaccine will be quadrivalent, meaning they will protect against four flu viruses. There are special flu vaccines for older adults that provide stronger immunity.

Keep in mind that Covid-19 is not over yet. Both the flu and Covid-19 can spread at the same time. Given this, getting the flu vaccine is more important than ever - it will ensure fewer hospitalizations for influenza-related illnesses, so there are hospital beds available for critically ill Covid-19 patients.

When should I get the flu shot?

You should plan to get vaccinated before flu activity rises in your community. Given that flu season usually starts in October in the US, get your flu vaccination before the end of October. Remember, it takes about 2 weeks to build immunity after you get a flu shot. 

Pregnant women in their third trimester should get vaccinated as soon as the flu vaccine becomes available. This will protect both mother and baby. Pregnant women should not get the nasal spray flu vaccine. 

Children between 6 months and 8 years old who have never had flu vaccination before or had fewer than 2 doses of the flu vaccine in their lifetime should get 2 doses of the flu vaccine this year, spaced at least 4 weeks apart. If your child needs 2 doses of the flu vaccine, make sure both doses are done before the end of October when flu season begins.

Do I need both the flu vaccine and the Covid-19 vaccine?

Yes, you need to get vaccinated with both the flu vaccine and the Covid-19 vaccine. You can get both vaccines at the same time (in different arms to reduce soreness). But, again, the flu season is expected to occur even as Covid-19 continues, so you should get a flu shot and get vaccinated with a Covid-19 vaccine to protect yourself and your loved ones.


  1. https://www.cdc.gov/flu/about/burden/2019-2020.html
  2. https://www.hsph.harvard.edu/news/hsph-in-the-news/a-sharp-drop-in-flu-cases-during-covid-19-pandemic/