Who Needs a Flu Vaccine and When
https://www.cdc.gov/flu/prevent/vaccinations.htm
For 2021-2022, CDC recommends use of any licensed, age-appropriate flu vaccine as an option for vaccination this season. These include:

injectable flu vaccines, or flu shots. These include:
Flu shots that are made with inactivated viruses.
One flu shot that is made without influenza viruses.
A live attenuated influenza vaccine, which is given by nasal spray.
Who should get a flu vaccine this season?
Everyone 6 months and older should get a flu vaccine every season with rare exceptions. Vaccination is particularly important for people who are at higher risk of serious complications from influenza. A full listing of people at Higher Risk of Developing Flu-Related Complications is available.

Flu vaccination has important benefits. It can reduce flu illnesses, doctors’ visits, and missed work and school due to flu, as well as prevent flu-related hospitalizations and deaths.

Different flu vaccines are approved for use in different groups of people.

-There are flu shots approved for use in children as young as 6 months old and flu shots approved for use in adults 65 years and older.
-Flu shots also are recommended for pregnant people and people with certain chronic health conditions.
-The nasal spray flu vaccine is approved for use in non-pregnant people who are 2 years through 49 years of age. People who are pregnant and people with certain medical conditions should not receive the nasal spray flu vaccine.
There are many vaccine options to choose from. CDC does not recommend any one flu vaccine over another. The most important thing is for all people 6 months and older to get a flu vaccine every year.

If you have questions about which flu vaccine to get, talk to your doctor or other health care professional. More information is available at Who Should Get Vaccinated https://www.cdc.gov/flu/prevent/whoshouldvax.htm