COVID-19 Vaccines

The COVID-19 pandemic is a public health emergency. Manufacturers have responded to this urgent need by developing vaccines for the new coronavirus as quickly and safely as possible.

In the United States, the Food and Drug Administration (FDA) is responsible for protecting the public health in partnership with the United States government and others. The FDA can grant an emergency use authorization (EUA) to a manufacturer if it provides enough evidence that a vaccine is safe and effective.

The government (via the FDA) has selected vaccines that are promising. It has also helped fund large-scale production of these vaccines while safety data were being collected. This was done so that distribution of vaccines could begin quickly after they receive emergency approval.

The approval of a vaccine is not affected by having the clinical trial and the manufacturing process take place at the same time. If a vaccine does not meet standards, then it will not be used.

The COVID-19 vaccines are being held to the same standards used to assess the safety and effectiveness of other vaccines currently available in the United States. The only COVID-19 vaccines the FDA will approve for use are those that meet these standards. 

The approval process has many layers. In addition to a careful review by the FDA, independent scientific and public health experts study the safety and efficacy data to offer input on whether the vaccines should be approved.

Even after vaccines are distributed, monitoring for safety will continue. 

It is quite likely that your doctors and other clinicians you trust every day already have received these vaccines.

The FDA has authorized three COVID-19 vaccines for use in the United States as of Feb. 27.

Two COVID-19 vaccines currently available in the United States are messenger RNA, also known as mRNA, vaccines. Researchers have been studying mRNA vaccines for decades.

Unlike other vaccines, mRNA does not use an inactive form of the virus to cause your body to react and learn to defend itself. Instead, mRNA delivers instructions to your body to tell it how to protect itself against the virus.

Two COVID-19 vaccines approved in the U.S. require two shots in total. The second shot, sometimes called a booster shot, should be given three or four weeks after the first one. Importantly, you cannot get COVID-19 from being vaccinated.

A third vaccine that is approved for use in the U.S. requires only one shot.

The vaccine you will be given depends on the supply at the time you are vaccinated. You will most likely not get to choose which vaccine you will get. All the approved COVID-19 vaccines will be effective in protecting you against COVID.

In December, the FDA approved two vaccines for emergency use in the United States. Emergency use may be granted if there is strong enough evidence that the vaccines are safe and effective. The first vaccinations began Dec. 14. On Feb. 27, the FDA approved a third vaccine for emergency use in the U.S.

Supplies are limited, but more vaccines will become available in the weeks and months ahead. The government is planning to order enough doses for everyone in the United States to be fully protected.

When supplies are limited, the Centers for Disease Control and Prevention (CDC) recommends offering the vaccines in phases so that those at highest risk can get them sooner: 

• Phase 1a: Health care workers and people in long-term care facilities 
• Phase 1b: Essential workers, such as fire fighters, grocery store workers, and public transit workers, and people who are 75 or older 
• Phase 1c: People older than 65 and people 16-64 with underlying health conditions who are at higher risk for severe COVID-19 illness 

The order of who gets the vaccines will be decided by each state. Contact your care provider to find out more. You also can visit CDC.gov/CovidVaccine to find your state’s health department website to learn the plan in your area.  

People at increased risk of severe illness from COVID-19 include people with existing:

• Heart conditions 
• Lung disease (chronic obstructive pulmonary disease or COPD)
• High blood pressure
• Diabetes 
• Obesity 
• Cancer
• Illnesses that lower the immune system’s ability to fight infection (for example, people undergoing cancer treatments or organ transplants) 

However, experts are still learning about COVID-19. Other medical conditions might also increase your risk, for example moderate-to-severe asthma or being overweight. 

For the full list of health conditions, visit the CDC’s website: People With Certain Medical Conditions. 

People who are pregnant have a higher chance of severe illness from COVID-19. However, there is very little data about these vaccines being given during pregnancy. Research into the safety of the vaccine during pregnancy is being planned.

If you are pregnant, ask your care provider about your overall risk and to help make the right choice for you. 

According to the CDC, severe illness from COVID-19 means that you experience any of the following:

• Are admitted to the hospital
• Need care in the intensive care unit
• Require help or a mechanical device to breathe

Severe illness can also lead to death.

Check with your care provider or nearby drugstore. Visit your local health department’s website to learn your state’s plan.

The U.S. government is working to ensure that the vaccines will be distributed in a convenient way and at no cost.

There may be some side effects that are mostly mild. Participants in the vaccine clinical trials reported having a fever or aches lasting a day or two after getting a shot. Other side effects may be arm soreness or headache.

Although rare, a few people have had a severe allergic reaction after getting the vaccine. When you get your shot, you will be asked to stay on site for at least 15 minutes. If you have a bad reaction, care providers can give you medicine to treat it. There are safeguards in place to monitor and take care of you.

Overall, the vaccines were found to be safe.

Yes. Not everyone you meet will have gotten a shot. While the vaccine protects you from getting sick with COVID-19, you still might be able to give the virus to others.

So, wear a mask, keep a safe distance from others, and wash your hands often. 

For the latest guidance, visit “When You’ve Been Fully Vaccinated” from the CDC.

It’s not clear how long the vaccine will protect you. More research is being conducted to understand this over a longer time. For now, getting the vaccine is recommended to prevent COVID-19.