All COVID-19 vaccines that have approval for use are effective at reducing the risk of a COVID-19 infection. The best vaccine for an individual is one they can access and feel comfortable taking.
Coronavirus data
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub for the most recent information on COVID-19.
The Food and Drug Administration (FDA) has
However, different vaccines are available globally. Many countries are starting to approve the new Novavax vaccine and the Oxford AstraZeneca vaccine that is common in Europe.
Like all medical treatments and medications, vaccines come with risks and benefits.
The data on COVID-19 vaccines show that side effects
Read more to learn about the approval status, dosage, efficacy, and side effects of each COVID-19 vaccine.
The
Overview
It uses a lipid, or a fatty acid, to deliver a piece of the virus’s genetic code. However, it does not contain the virus — rather, it contains a piece of messenger RNA (mRNA) that codes for the virus’s unique spike protein.
The body responds to this spike protein as an intruder and develops the immune reaction it needs to fight it. The vaccine teaches the body how to fight the COVID-19 virus when it encounters the real thing.
The vaccine’s contents leave the body and do not alter a person’s genetic code.
It does not contain:
- gelatin
- fetal cells
- latex
- eggs or other common allergens
- latex
- preservatives
- metals
- antibiotics
Approval status
The FDA
Dosage
The initial series is two injections, at least 21 days apart, and a booster requires a third shot.
The dosage is:
- Ages 5-11: two 0.2 milliliter (mL) doses
- Ages 12-15: two 0.3 mL doses
- Ages 16 and older: two 0.3 mL doses
It is safe to mix and match this vaccine with others.
Side effects
The vaccine’s side effects are typically mild, and some people report having more side effects after the second vaccine.
They commonly report cold and flu-like symptoms such as:
- fever
- headache
- muscle aches
- soreness at the injection site
- nausea
- chills
- fatigue
The side effects usually disappear within a few days. They happen because of the immune system’s reaction to the injection, so having side effects shows that the vaccine is working.
Efficacy
According to the CDC, the full series of the vaccine is
In children ages 5–15 and people with immunocompromising conditions, the vaccine was at least 90% effective.
Among adults without immunocompromising conditions between March 11 and August 15, 2021, the vaccine offered 88% efficacy against hospitalization. This time period extends into the Delta wave of the pandemic.
Preliminary data from Pfizer showed that three doses of the vaccine could neutralize the Omicron variant.
Other research is still ongoing. A
The
Overview
Although it works similarly to the Pfizer vaccine, it delivers a slightly higher dose.
Like Pfizer, it contains mRNA that gives instructions for fighting the spike protein on the COVID-19 virus. This produces an immune reaction that trains the body to fight the virus if it encounters it in the real world.
The vaccine’s contents leave the body and do not alter a person’s genetic code. It does not contain any of the following:
- viruses
- bacteria
- fetal cells
- eggs
- preservatives
- metals
- antibiotics
- latex
Approval status
The
Moderna is not approved for use in children.
Dosage
The initial Moderna series requires two injections, with a third shot as a booster.
It has earned an emergency use authorization for people over the age of 18. Each dose is 0.5 mL, and the two shots should be at least 28 days apart.
Like the Pfizer vaccine, it is safe to mix and match this vaccine with others.
Side effects
Because they are both mRNA vaccines, the side effects of Moderna are similar to those of Pfizer.
Some people report mild cold or flu-like symptoms shortly after getting vaccinated with side effects more frequently appearing after the second vaccine than the first. Some common side effects include:
- headache
- fatigue
- chills
- fever
- body aches
- gastrointestinal issues
- redness, swelling, and pain at the injection site
Efficacy
Among adults without immunocompromising conditions between March 11 and August 15, 2021, Moderna was
A
The
On May 5, 2022, the FDA
Overview
Unlike Pfizer and Moderna, it is not an mRNA vaccine. Instead, it works similarly to traditional vaccines.
The vaccine uses a weakened form of a harmless adenovirus that delivers genetic code for the unique COVID-19 spike protein. This creates an immune reaction that prepares the body to fight COVID-19. The vaccine’s contents leave the body and do not alter a person’s genetic code.
It cannot infect a person with COVID-19 or the adenovirus, and it does not contain:
- preservatives
- antibiotics
- metal
- latex
- fetal parts
- eggs
The injection is generally less effective than the Moderna and Pfizer vaccines.
The CDC urges people to choose the mRNA vaccines unless they are inaccessible. While J&J/Janssen is safer than going unvaccinated, it may have worse side effects than other vaccines.
Approval status
The
The vaccine is not approved for children or anyone under the age of 18.
Side effects
The most common side effects of this vaccine include mild cold or flu-like symptoms such as nausea, fever, chills, and muscle aches.
Very rarely, however, a person may develop a blood clot.
The CDC estimates that roughly
Dosage
The J&J/Janssen vaccine is a single-dose vaccine. It has an emergency use authorization in the United States for people over the age of 18.
A person can also get a single dose booster, but the CDC recommends choosing Pfizer or Moderna instead. It is safe to mix and match this vaccine with others.
Efficacy
Between March 11 and August 15, 2021, a time period that included the Delta wave but not Omicron, the J&J/Janssen vaccine was 71% effective in preventing COVID-19 hospitalization.
The Oxford AstraZeneca vaccine works very similarly to the J&J/Janssen vaccine.
Overview
It uses an adenovirus to deliver the COVID-19 spike protein into the body. This creates an immune reaction that trains the body to fight the virus if it encounters it again.
Approval status
The AstraZeneca vaccine does not have FDA approval in the United States. However, it is popular in Europe because it is less expensive to produce than mRNA vaccines and is easier to store.
Dosage
The
Side effects
Some common side effects
- fever
- chills
- muscle aches
- flu and cold-like symptoms
- pain at the injection site
In rare cases, the AstraZeneca vaccine may cause blood clots. The risk of blood clots from COVID-19 is exponentially higher.
Efficacy
The AstraZeneca vaccine prevents symptomatic infection in 6 out of 10 people. Early trials, prior to Delta and Omicron, showed an 80% efficacy at preventing hospitalization.
The Novavax vaccine uses older vaccine technology — specifically, a protein subunit.
Overview
This vaccine delivers an antigen synthesized from the COVID-19 spike protein to train the body to fight the virus. It does not contain a live virus, and the spike antigen cannot replicate.
Approval status
Novavax is not yet approved for use in the U.S., but a request for an emergency use authorization has been submitted. As of November 2021, it is approved for use in Indonesia and the Philippines.
Dosage
The
It is safe to mix and match this vaccine with others.
Side effects
Side effects include:
- fatigue
- headache
- fever
- muscle pain
- injection site swelling, pain, and redness
Efficacy
In clinical trials, the efficacy of Novavax against mild, moderate, and severe disease was
There are four types of COVID vaccines in use or in clinical trials:
| Type | How they work | Available vaccines |
|---|---|---|
| mRNA | These use messenger RNA to give the body’s cells information about how to fight the virus, usually by providing information about the virus’s spike protein. | Pfizer-BioNTech, Moderna |
| Whole virus | These use whole viruses to provoke an immune response. | Coronavac, Covilo, Covaxin |
| Protein subunit | These use a component of the virus, usually a protein, to train the body how to fight a virus by inducing an immune response. | Novavax |
| Viral vector | These vaccines use a harmless virus to train the body how to fight a harmful virus. | J&J/Janssen, Oxford-AstraZeneca |
Current
The availability of vaccines varies from location to location. In areas that offer multiple vaccines, a person can often choose their vaccine. This might require going to a specific provider or scheduling the vaccine for a specific day.
It is usually safer to get the first available vaccine to maximize a person’s protection against COVID-19.
All currently approved COVID-19 vaccines are safe for use and reduce a person’s chance of severe illness with the virus.
Although all vaccines come with side effects, the risk of side effects from COVID-19 remains much higher. Except for a severe allergic reaction or a known allergy, there is no reason to avoid a COVID-19 vaccine.