There are three COVID-19 vaccines approved for use in the U.S. The Pfizer, Moderna, and Johnson & Johnson vaccines are all highly effective in protecting you from the virus that causes COVID-19.

The Pfizer vaccine received full FDA approval on Aug. 23 and is no longer under emergency use authorization (EUA). It will now be marketed under the name Comirnaty.

Two other vaccines, from Novavax from AstraZeneca, are not available in the U.S.

Vaccines continue to lower your risk for severe disease, hospitalization, and death, even against the widespread Delta variant of COVID-19.

But each is slightly different. Compare them below. If you’re still not sure which vaccine is best for you, talk to your doctor.

Vaccine developer:

Pfizer

Moderna

AstraZeneca

Johnson & Johnson

Novavax

How it works

Messenger RNA

Messenger RNA

Inactivated cold virus

Modified cold virus 

Stabilized form of the coronavirus spike protein

When approved/expected approval 

Given full FDA approval Aug. 23, 2021

Dec. 18, 2021 

Not yet available. Phase III clinical trials in progress as of Feb. 27

Feb. 27

Not yet available. Results from phase III clinical trials published June 14.

What percentage of people did it protect from getting infected in clinical studies? 

95% 

94.1% 

70% 

66.1% globally; 72% in the U.S.; 86% effective against severe disease

89.7%

Who is it recommended for?

People 12 years and older

People 18 years and older

Not yet available

People 18 years and older

Not yet available

How many shots do you need?

Two doses, 3 weeks apart

Two doses, 4 weeks apart

Two doses, a month apart

One dose

Two doses, 21 days apart

When might you become eligible for a booster shot?

8 months after your second dose

8 months after your second dose

 

To be determined

 

What are the side effects?

Fatigue, headache, chills, muscle pain, especially after the second dose

Fever, muscle aches, headaches lasting a few days. Effects worse after second dose. 

Pain where you get the shot, fever, muscle aches, headache

Pain where you get the shot, headache, fatigue, muscle pain

Pain and tenderness where you get the shot, fatigue, headache, muscle pain

Any warnings?

The FDA issued a warning in June about heart inflammation. Since April 2021, there have been more than a thousand reports of myocarditis and pericarditis. These cases are still relatively low.

The FDA issued a warning in June about heart inflammation. Since April 2021, there have been more than a thousand reports of myocarditis and pericarditis. These cases are still relatively low.

 

In July, the FDA issued a warning about an increased risk for  developing Guillain-Barre syndrome.

 

What about pregnant women and nursing moms?

Pregnant women or nursing moms who want the COVID-19 vaccine should get one, experts say. The vaccine has not yet been studied in pregnant women. Read guidelines here

There's limited data. Studies in rats that were immunized before and during pregnancy found no safety concerns. The CDC says pregnant women may choose to receive the vaccine.

Not yet available

Discuss your options with your health care provider. 

Not yet available

Is there anyone who shouldn’t get the vaccine?

People with a history of serious allergic reactions, anyone with a history of allergic reactions to vaccine ingredients, including polyethylene glycol, and anyone with a history of allergic reactions to polysorbate

People with a history of serious allergic reactions, anyone with a history of allergic reactions to vaccine ingredients, including polyethylene glycol, and anyone with a history of allergic reactions to polysorbate

Not yet available

Anyone who’s had an allergic reaction to an ingredient in the vaccine, like polysorbate 

Not yet available

Any significant side effects? 

Extremely rare cases of anaphylaxis in people who received the vaccine.

Extremely rare cases of Bell's palsy, a type of temporary facial paralysis, reported in people who received the vaccine.

Extremely rare cases of anaphylaxis in people who received the vaccine.

Extremely rare cases of Bell's palsy, a type of temporary facial paralysis, reported in people who received the vaccine.

Four total serious side effects, including two cases of transverse myelitis

There is a possible, rare relationship between this vaccine and blood clots with low platelets.

Not yet available

What about people with lowered immune function? 

OK for people whose immune function is lowered by HIV or immunosuppressing drugs if they have no other reasons to avoid it. There is limited safety data in this group. Discuss the benefits and risks with your doctor.

OK for people whose immune function is lowered by HIV or immunosuppressing drugs if they have no other reasons to avoid it. There is limited safety data in this group. Discuss the benefits and risks with your doctor.

Not yet available

Not yet available

Not yet available

What about people with autoimmune diseases?

No data is available on the safety or effectiveness of mRNA vaccines in people with autoimmune disease. People with autoimmune conditions may still get the shots if they have no other reasons to avoid vaccination.

No data is available on the safety or effectiveness of mRNA vaccines in people with autoimmune disease. People with autoimmune conditions may still get the shots if they have no other reasons to avoid vaccination.

Not yet available

Not yet available

Not yet available

Is the vaccine safe for people with a history of Guillain-Barre syndrome (GBS)?

To date, no cases of GBS have been seen in people vaccinated for COVID-19. The CDC says a history of GBS is not a reason to avoid vaccination.

To date, no cases of GBS have been seen in people vaccinated for COVID-19. The CDC says a history of GBS is not a reason to avoid vaccination.

Not yet available 

There’s a possible, but rare risk in developing Guillain-Barre syndrome after this vaccine.

Not yet available

 

WebMD Medical Reference Medically Reviewed by Brunilda Nazario, MD on August 27, 2021

Sources

StatNews.com: “Detailed data on AstraZeneca-Oxford Covid-19 vaccine show it has moderate efficacy.”

The New York Times: “Moderna Applies for Emergency F.D.A. Approval for Its Coronavirus Vaccine.”

USA Today: “Are there side effects to a COVID-19 vaccine? What are the 'ingredients'? The cost? Answers to your vaccine questions,” “Moderna becomes second company to request emergency FDA authorization for COVID-19 vaccine candidate,” “Pfizer to seek approval from FDA 'within days' after further analysis finds COVID-19 vaccine 95% effective.”

Medscape: “CDC Panel Recommends Pfizer's COVID-19 Vaccine for People 16 and Over,” “Experts: Pregnant Women Can Get COVID-Vaccine,” “FDA to Warn J&J Vaccine Can Increase Guillain-Barré Risk: Media.”

The New England Journal of Medicine: “Interim Results of a Phase 1-2a Trial of Ad26.COV2.S Covid-19 Vaccine.”

News release, Johnson & Johnson.

CDC, Advisory Committee on Immunization Practices meeting, Jan. 27, 2021: “Types of Vaccines Available,” “Johnson & Johnson's Janssen,” “Myocarditis and Pericarditis.”

Yale Health: “Who should and shouldn’t get the COVID-19 vaccine.”          

The New England Journal of Medicine: “Safety and Efficacy of NVX-CoV2373 Covid-19 Vaccine.”

National Institutes of Health: “U.S. clinical trial results show Novavax vaccine is safe and prevents COVID-19.”

NPR: “A New Type Of COVID-19 Vaccine Could Debut Soon.”

FDA: “FDA Approves First COVID-19 Vaccine.”

Reuters: "Novavax again delays seeking U.S. approval for COVID-19 vaccine."

European Medicines Agency: "AstraZeneca’s COVID-19 vaccine: benefits and risks in context."

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