Replies

There are three COVID-19 vaccines approved for use in the U.S., with a fourth still in clinical trials. The Pfizer, Moderna, and Johnson & Johnson vaccines are all highly effective in protecting you against the virus that causes 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
How it works	Messenger RNA	Messenger RNA	Inactivated cold virus	Modified cold virus
When approved/expected approval	Dec. 11, 2021	Dec. 18, 2021	Not yet available. Phase III clinical trials in progress as of Feb. 27	Feb. 27
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
Who is it recommended for?	People 12 years and older	People 18 years and older	Not yet available	People 18 years and older
How many shots do you need?	Two doses, 3 weeks apart	Two doses, 4 weeks apart	Two doses, a month apart	One dose
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
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.
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
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.
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
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
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.