What to know about the COVID-19 vaccine

Gloved hands holding COVID-19 vaccine

While the emergency stage of COVID-19 has ended, the virus continues to circulate and mutate. Staying current on COVID-19 vaccination is the best way to protect your health and community.

Today, COVID-19 is endemic rather than pandemic. This means it has a constant presence in communities – similar to the flu. New strains, like EG.5 (Eris), and seasons when more people are indoors, bring a spike in illness and hospitalization. Preventing severe illness means getting an updated COVID-19 vaccine.

prevented millions of hospitalizations and deaths since it first became available in the U.S. in 2020. It’s your best protection against getting COVID-19, developing a severe infection, hospitalization and even death.

Here is what you need to know about the COVID-19 vaccines, including how safe and effective they are and when to get an updated vaccine.

How effective is the COVID-19 vaccine today?

Like any vaccine, the COVID-19 vaccine teaches your body to recognize specific dangerous pathogens so your immune system is prepared to fight off that infection in the future. The vaccines introduce small parts of germs to your body that are weakened or dead, collectively called antigens. These antigens trigger your body's natural immune response without causing illness.

With the help of public health partners, the CDC routinely monitors vaccine effectiveness to detect changes due to emerging variants or waning of vaccine protection.

The vaccine’s effectiveness is a measure of how well it works to prevent illness, infection or severe outcomes caused by exposure to COVID-19. Studies show that for the first few months after your annual COVID-19 vaccine, your likelihood of getting COVID is substantially decreased. In addition, your likelihood of developing severe disease, ending up in the hospital or dying is significantly lower in the first six months to a year after your immunization. (That’s why it’s important to get a vaccine each year.)

Even if you are at low risk for severe COVID-19, getting vaccinated regularly can decrease the number of times you get infected, how sick you get and how likely you are to spread it to other people.

Who should get the COVID-19 vaccine?

All children, adults and seniors should stay up to date on the COVID-19 vaccination. Everyone 6 months and older is eligible to receive the annual vaccine and people who have health conditions, are over 65 or are immunocompromised may be eligible for additional doses. These extra doses are usually available in the spring.

According to the CDC, the COVID-19 vaccine remains the best protection against severe disease, hospitalization and death in children, teens and adults. Staying current on vaccination means getting updated vaccines for the fall and winter seasons. The virus is constantly changing, and protection decreases over time.

How does COVID-19 spread?

This virus is highly transmissible and can spread from person to person even before someone develops symptoms. It’s carried on respiratory droplets that can land on surfaces or in someone’s mouth or nose when we talk, sneeze or cough. It’s also carried on respiratory aerosols, which can stay in the air and accumulate in rooms with poor ventilation.

The best protection against COVID-19 is avoiding contact with those infected or with COVID symptoms. This can be hard to do, so you should stay updated with your annual COVID-19 vaccine. When COVID-19 is spreading in your community, consider wearing masks indoors and improving ventilation. It’s also a good practice to wash your hands frequently and clean surfaces, even if COVID-19 isn’t likely to spread this way.

Is the COVID-19 vaccine safe?

Yes. Millions of people in the U.S. and globally have received COVID-19 vaccines in the most comprehensive safety monitoring program in U.S. history. Only vaccines that meet rigorous standards for safety and efficacy are approved for emergency use by the FDA.

Vaccine trials included a wide range of people. This included people of different ages, races, sexes and health conditions, including HIV, diabetes and lung disease.

Vaccine safety monitoring by the CDC and other health organizations worldwide continues even after approval or authorization. If any safety concerns arise, they are thoroughly investigated. Millions of people have received the COVID-19 vaccines since 2020. Evidence shows immunization is both safe and effective. In short, it’s much safer to receive the COVID-19 vaccine than it is to develop COVID-19.

What are the potential vaccine side effects?

All medical treatments have some degree of risk. For vaccines, that risk is typically small. Many vaccines have mild side effects, from soreness at the injection site to a slight fever, body aches and a headache. Side effects typically occur within two days and are entirely over within seven days. Some people have no reactions at all.

It’s important to know that risks reported in connection with the COVID-19 vaccine are significantly lower — and less severe — than risks associated with contracting the virus.

Speak to your primary care physician if you're concerned about the vaccine's safety or have specific health questions.

Can you get a COVID-19 vaccine if you’re pregnant, planning to become pregnant or breastfeeding?

The CDC recommends the updated COVID-19 vaccine to all people over 6 months of age, including women who are pregnant, planning to become pregnant and breastfeeding.

Unvaccinated pregnant women who contract COVID-19 are more likely to experience a severe illness than those who are not pregnant. Pregnant people with COVID-19 are also more likely to have complications with their pregnancy, such as miscarriage and early delivery.

Getting vaccinated can help protect you and your baby from complications due to a severe case of COVID-19 – including delivering a premature or stillborn infant. Newborns whose mothers received a COVID-19 vaccine have better protection against the virus during their first six months. (Children can get a COVID-19 vaccine when they are six months old, but cannot be vaccinated before that.)

Speak to your healthcare provider if you have questions or concerns about vaccination during pregnancy or breastfeeding.

Can you get COVID-19 from the vaccine? Can it cause a false-positive test result?

No, getting COVID-19 from this vaccine is impossible and won’t produce a positive COVID-19 test result. The vaccines aren’t made from the live virus and do not contain the virus that causes COVID-19. Instead, these vaccines typically use a small piece of the virus's genetic material (mRNA) to stimulate an immune response. This response helps your body build immunity to the virus without causing the disease itself.

You may feel unwell after getting vaccinated, but this is a sign of your immune system starting to activate to protect you. However, you could still catch the virus after being immunized and before your body’s immune system has reached its full ability to fight the virus.

Much like the flu vaccine, COVID-19 vaccines are not 100 percent effective, which means there is a chance you could contract COVID-19. However, the COVID-19 vaccine protects you against severity, hospitalization and even death.

If you have been vaccinated and test positive, you should self-isolate, monitor your symptoms and contact your physician.

Will the COVID-19 vaccine alter my DNA? What is an mRNA vaccine?

No, the COVID-19 vaccine will not alter your DNA. It also does not enter the nucleus of your cells. The COVID-19 vaccine is an mRNA vaccine. While this is the first mRNA vaccine, it uses a technology that scientists have been perfecting for decades. (Learn about other types of vaccines.)

In our bodies, our naturally created mRNA – or messenger RNA – delivers recipes to our cells on how to make specific proteins. An mRNA vaccine capitalizes on that process using laboratory-developed mRNA with information on how to defeat a virus. In this case, the COVID-19 vaccine delivers a blueprint to your cells on how to make the spike protein, an essential piece of the COVID-19 virus. This blueprint serves as a wanted ad, telling your body to be on the lookout for the spike protein and to develop an immune response to defeat it. Then, your natural cell processes take over.

The vaccine prepares your body to identify and attack the SARS-CoV-2 virus if it ever enters your system. Within a matter of days, the mRNA from the vaccine is destroyed by your cells, leaving no permanent mark on your body.

Can I still get COVID-19 after being vaccinated?

Yes, it’s still possible for you to contract COVID-19 after receiving the vaccine. No vaccine is 100 percent effective, but the COVID-19 vaccination is your best protection against a severe infection, hospitalization and even death. Getting vaccinated every year helps reduce the number of times you get COVID-19 and the severity of your infections.

I recently had COVID-19. Should I still get the COVID-19 vaccine?

If you’ve had COVID-19 in the past 90 days, you can postpone getting your vaccine until that 90-day window has elapsed. If you are still symptomatic and infectious, you should postpone your vaccine until you are well and no longer contagious.

Otherwise, yes, you should still get the COVID-19 vaccine, even if you’ve had COVID-19.

Who should not get the COVID-19 vaccine?

You should not get the COVID-19 vaccine if you have had a severe allergic reaction to any of the mRNA vaccine ingredients after a previous dose of this vaccine. See the ingredient list here.

You can still get a vaccine if you have a food allergy. If you've ever had a severe allergic reaction, you will need to be monitored for 30 minutes after your vaccine. Consult your physician if you have any concerns about potential allergic reactions.

You should not get vaccinated if you have a fever on the day of your appointment. Instead, postpone vaccination until your fever subsides.

Do not get vaccinated if you have a confirmed or suspected case of COVID-19. Wait until you recover.

Should children be vaccinated?

Yes, children older than 6 months can get vaccinated against COVID-19. Note that not all COVID-19 vaccines are licensed for children. Your pediatrician should have an appropriate option for your child.

How long will it take for the vaccine to start protecting me?

The vaccine immediately begins teaching your immune system to protect you against COVID-19. However, the time it takes to gain full immunity to the virus will depend on what vaccine you receive. Generally, you should be protected about 14 days after receiving your annual vaccine. The vaccine is not 100 percent effective against catching COVID. However, the vaccine is your best defense against a severe case, hospitalization and even death.

How many doses of the COVID-19 vaccine do I need?

You should get an updated COVID-19 vaccine every year. People who have preexisting medical conditions, are over the age of 65 or are immunocompromised may be eligible for additional doses. And some children may need two doses if they’ve never been vaccinated.

How long will the vaccine protect me? Will I need to get vaccinated multiple times over my lifetime?

Vaccines for respiratory viruses are notoriously short-acting and the COVID-19 vaccine is proving to be the same. That’s why you should get an updated dose every year. People who have pre-existing medical conditions, are over the age of 65 or are immunocompromised may be eligible for additional doses. The more recent your COVID-19 vaccine, the better protected you are.

Will the current COVID-19 vaccines protect against any new virus strains?

Similar to flu viruses, coronaviruses change slightly over time. The CDC recommends everyone over 6 months of age get an annual COVID-19 vaccine to stay protected against mutations. This is in addition to your annual flu shot. Because of how mRNA vaccines are created, scientists can quickly isolate the part of the virus that needs to be recognized by our bodies and produce an effective vaccine.

How much does the COVID-19 vaccine cost?

Your insurance, Medicare or Medicaid covers vaccination. The CDC is temporarily providing vaccination coverage through December 2024 for those who aren’t insured or underinsured through the Bridge Access program.

Check with your provider to verify any fees.

Can I still transmit COVID-19 to others after getting the vaccine?

While COVID-19 vaccines have been shown to be highly effective at preventing severe illness, hospitalization and death from COVID-19, it is still possible for vaccinated individuals to contract and transmit the virus to others. However, the risk is significantly reduced compared to unvaccinated individuals. If you have COVID-19, stay home for at least five days and be sure to wear masks around other people for at least 10 days.

Can COVID-19 vaccines cause heart problems?

Myocarditis, an inflammation of the heart, has been reported in rare instances after receiving the COVID-19 vaccination. This is slightly more common in adolescent and young adult males. Vaccine-related myocarditis is almost always treatable with anti-inflammatory medications and patients recover quickly.

Studies have found that myocarditis is also a common complication of COVID-19. However, COVID-19-associated myocarditis is more common, more severe and harder to treat than vaccine-related cases. In short, you’re more likely to develop myocarditis from COVID-19 than you are from getting the COVID-19 vaccine.

Can you get the COVID-19 vaccine at the same time as your flu shot or RSV shot?

It’s okay to schedule your updated annual COVID-19 vaccine together with the annual flu shot and the RSV shot. You might have a little soreness in both arms, and there’s a slightly higher chance of feeling fatigue and a low fever from getting multiple shots together. But convenience outweighs the risk for most people.

However, if you typically have side effects from vaccines, you may want to space these out one to two weeks apart.

Will the COVID-19 vaccine protect me from getting long COVID?

We know people who have been vaccinated are less likely to develop long COVID complications. However, it’s important to know that a vaccine is just one precaution you’ll need to keep yourself safe. That’s because an immunization alone won’t protect you from long COVID. We recommend everyone avoid infection as best you can. And if you do contract COVID-19, take steps to shorten your illness by getting appropriate medication from your physician. Those are critical things you should do in addition to getting your annual vaccine.

Emily Landon, MD

Emily Landon, MD

Dr. Emily Landon specializes in infectious disease, and serves as Executive Medical Director for infection prevention and control.

Learn more about Dr. Landon.
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