COVID-19 Booster Shots: What You Need to Know

booster shot grand journey - three vials of vaccine with people climbing on them

COVID-19 booster shots are here. 

In the United States, PfizerModerna, and Johnson & Johnson have each developed their own booster shots.

So far, the Food and Drug Administration (FDA) has authorized booster shots of Pfizer and Moderna five months after the second dose. Pfizer boosters have been recommended for everyone ages 5 years and older (as well as a second booster for certain immunocompromised children 12 and older and all those aged 50+), and Moderna for those 18 years and older. The FDA has also authorized a Johnson & Johnson booster for all adults (18+) who received a J&J vaccine as early as two months after their initial shot.

Eligible adults are able to choose any authorized COVID-19 booster—regardless of the vaccine type used for their initial vaccination (although Pfizer and Moderna vaccines are being recommended by the Centers for Disease Control and Prevention in most situations). Children and teens ages 5 to 17 who have completed Pfizer's primary series are only eligible for the Pfizer booster.

Because manufacturers have eagerly presented the FDA with clinical trial data for COVID-19 booster doses, there's a lot we already know about them. Moderna will administer half-size doses for its third shot, for example, and Johnson & Johnson's booster dose increases immunity nine-fold. 

Additionally, people 12 years of age and older with certain kinds of immunocompromise and all people age 50+ who have received an initial mRNA booster dose at least four months ago are eligible for a second booster dose.  

Adults who have received a primary vaccine and booster dose of Johnson & Johnson’s vaccine at least four months ago can now receive a second booster using an mRNA COVID-19 vaccine.

Here, we asked experts what else we should know about boosters, from potential side effects to the intended rollout plan and timeframe. There's good news: After the bumpy road to COVID-19 vaccine distribution the first time around, the U.S. is more prepared than ever. 

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. CDC strengthens recommendations and expands eligibility for COVID-19 booster shots.

  2. Centers for Disease Control and Prevention. COVID-19 vaccine booster shots.

  3. Moderna. Moderna announces positive initial booster data against SARS-CoV-2 variants of concern.

  4. Johnson & Johnson. Johnson & Johnson announces data to support boosting its single-shot COVID-19 vaccine.

  5. Centers for Disease Control and Prevention. CDC recommends additional boosters for certain individuals.