On November 19, 2021, the FDA amended its emergency authorization for the Moderna and Pfizer-BioNTech COVID-19 vaccines to allow single booster doses for everyone 18 and older.

Children ages 5 to 17 are eligible for initial vaccination shots but not for booster shots (yet!).

Why Get a Booster Shot

COVID-19 vaccines effectively reduce the risk of severe disease, hospitalization, and death. However, ongoing research shows protection against the virus that causes COVID-19 may decrease over time. According to the CDC, “This lower effectiveness is likely due to the combination of decreasing protection as time passes since getting vaccinated, as well as the greater infectiousness of the Delta variant.”

A booster dose for vaccine recipients can help to enhance and sustain the body’s defenses against COVID-19.

Booster Shot Eligibility

With the recent FDA amendment, all people 18 years and older are eligible for a booster shot.

If you received Pfizer-BioNTech or Moderna vaccines, get a booster if it’s been at least 6 months since completing your primary COVID-19 vaccination series.

If you received Johnson & Johnson’s (J&J) Janssen, get a booster if it’s been at least 2 months since your initial vaccination.

Choosing a Booster Regardless of which vaccine you originally received, any of the COVID-19 vaccines authorized in the United States can be used for the booster dose. The FDA amended the Emergency Use Authorizations of each available COVID-19 vaccine to allow for heterologous or “mix and match” administration of a booster dose in eligible individuals following completion of primary vaccination.

According to the CDC, “You may choose which COVID-19 vaccine you receive as a booster shot. Some people may prefer the vaccine type that they originally received, and others may prefer to get a different booster. CDC’s recommendations now allow for this type of mix and match dosing for booster shots.”

Some people who received the J&J shot may decide to get a booster from Pfizer or Moderna. Those who received a Pfizer vaccine originally may choose a Moderna or J&J booster, etc.

Side Effects

The side effects from booster shots are similar to those from initial vaccination. According to the FDA, “The most commonly reported side effects by individuals who received a booster dose of the vaccines were pain, redness and swelling at the injection site, as well as fatigue, headache, muscle or joint pain and chills. Of note, swollen lymph nodes in the underarm were observed more frequently following the booster dose than after the primary two-dose series.”


So go ahead and make that appointment and get your flu shot and booster shot at the same time. (It’s safe!) Check your local pharmacy or vaccines.gov to schedule.