Everything You Need to Know about Flu Season 2021-2022

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woman coughing while covered with a blanket; Everything You Need to Know about Flu Season 2021-2022

There’s potential for high circulation of the flu in the months ahead. The main way to protect yourself and others is to get vaccinated. Here’s everything you need to know about this year’s flu season (2021-2022) from UnityPoint Clinic vaccine expert, Dr. Stephen Rinderknecht.

What to Expect for Flu Season 2021 – 2022 

How did the Pandemic Affect the Flu Season? 

“I have never witnessed a viral respiratory season with such little virus circulation as I did last winter (2020 – 2021). Influenza, RSV and common cold viruses typically lead the way in the upper Midwest. However, this past winter, there was minimal activity. Most experts agree the measures we took to decrease the spread of COVID-19, like masking and physical distancing, also decreased activity of other respiratory viruses,” Dr. Rinderknecht says.

He explains the severity of each flu season depends on three things:

  • Virus change. The more the flu strains in circulation change from previous seasons, the worse it can be. Strains to include in the flu vaccine are determined months before the flu season begins to allow for manufacturing time.
  • Vaccine match. It can be problematic for vaccine strains to be developed so far ahead of time. That’s because strains in circulation can change, even during the flu season. How closely aligned the vaccine is with the strains in circulation is important for keeping a flu season under control.
  • Mitigation measures. Severity of the flu season is also impacted by our mitigation measures, or, the things we’re doing to keep ourselves healthy, including masking, physical distancing, keeping gatherings small, staying in well-ventilated places and maintaining an overall healthy lifestyle.

What about Flu Antibodies & Immunity? 

“While it was great to have low flu activity last year (2020 – 2021) due to COVID-19 surges, it set us up with some hurdles for the upcoming season. The downside of no circulating influenza last season is there was no development of natural immunity. Depending on the prevalent strains each year, we depend on past exposure or vaccination to provide protection from severe disease in the following season,” Dr. Rinderknecht says.

Since most people don’t have any natural immunity from last year, it’s important to get flu shots in arms by the end of October.

Will the Increase in Summer Virus Activity Impact Flu Season? 

In an unusual twist, many hospitals and clinics have been dealing with an increase in viral activity during the late summer months.

“RSV and common cold viruses have been rampant, but we aren’t seeing summer influenza. Since immunity to these viruses is unique, I don’t feel this summer’s respiratory activity will influence the upcoming flu season,” Dr. Rinderknecht says.

He adds there’s no way to predict the timing of a flu season. In the upper Midwest, it typically peaks in winter months but could be as early as October or as late as April. 

What are the details of the 2021 – 2022 Flu Shot? 

What is a Quadrivalent Flu Shot? 

This year, for the first time, all adult and children’s flu vaccines are quadrivalent. That means they contain strains from four different flu viruses. Previously, all flu vaccines were trivalent and only protected against three strains of the flu.

“A quadrivalent flu vaccine contains two strains that are type A and two that are type B influenza. This is a good thing! The more strains in the vaccine, the better chance of matching the strains in circulation to keep our communities protected,” Dr. Rinderknecht says.

This year’s vaccine includes the same influenza B lineages from last season, but two new A strains. All the decisions on what strains go into the flu vaccines are determined by the World Health Organization’s (WHO) Global Influenza Surveillance and Response System. The decision is based on what flu strains are in circulation around the world.

What Type of Vaccine is the Flu Shot? 

We’ve learned a lot about types of vaccines since the COVID-19 vaccines have been such a big part of our lives. The flu vaccines aren’t developed with the mRNA or viral vector technology used in the COVID-19 vaccines. 

Instead, they’re in two basic categories:

  • Inactivated Influenza Vaccine (IIV). The IIV vaccines are produced by growing the flu virus in a variety of ways, including in eggs. Once grown, the virus is taken out and inactivated so it can’t cause the flu in the body. That inactivated virus has a protein (hemagglutinin) on its surface. Once injected as a shot, that protein tells our bodies to create antibodies for flu protection. There are many manufacturers of this type of vaccine.
  • Live Attenuated Influenza Vaccine (LAIV). The LAIV is a nasal spray, or sometimes called the FluMist. It’s unique in that it uses a weakened, but live, virus that doesn’t cause disease. When sprayed into the nose, it reproduces in the upper airway and generates an immune response. There is only one manufacturer of this type of vaccine. It’s only for those ages 2 through 49.

Dr. Rinderknecht says not to worry about the type of vaccine but to focus on getting any vaccine approved for your age group.

The Influenza Vaccine & COVID-19

Can I Get the Flu Shot and the COVID-19 Shot at the Same Time?

It is safe to get the flu shot and the COVID-19 vaccine at the same time. As a reminder, the flu shot only protects you from influenza, and the COVID-19 vaccine only protects you from the virus that causes COVID-19.

If you are getting more than one vaccine at your visit, be prepared to roll up both sleeves.

“Whenever more than one vaccine is given, they should be in different arms. The reason for this is to differentiate any local reactions like swelling, redness or pain. This is a standard practice for all vaccines, not just flu and COVID-19 vaccines,” Dr. Rinderknecht says.

At this time, there is no work being done on a flu and COVID-19 combination shot.

Can You Get COVID-19 and the Flu at the Same Time?

It’s possible to get the flu, as well as other respiratory illnesses, and COVID-19 at the same time. 

“Now that we can test for most of the common respiratory viruses with a single nasal swab, we know co-infection occurs. Some of the sickest children are hospitalized with multiple viruses present. For that reason, it’s best to protect yourself, your family and others by staying up to date with your vaccines,” Dr. Rinderknecht says.


Read 9 Tip to Recover Faster from COVID-19 or Flu, if you find yourself sick at home with these viruses.