Breakthrough COVID-19: What to Know

Medically Reviewed by Dan Brennan, MD on December 02, 2022
Written by Evan Starkman
4 min read

The best way to protect yourself and others from the virus that causes COVID-19 is to get vaccinated as soon as possible. The CDC recommends vaccination for everyone 6 months old and up.

The COVID-19 vaccines work extremely well. Still, no vaccine is 100% effective. There’s a chance you could catch the coronavirus after you get the vaccine. You might hear this called “breakthrough COVID-19.”

Some people who get a breakthrough infection have no symptoms and don’t get sick. But a small percentage get ill, go to the hospital, or die from COVID-19.

Breakthrough infection is more common for the Omicron variant because the mutation in this variant allows it to spread faster and, in some cases, get past the immunity your body may have built through vaccination. But the new bivalent booster will offer more protection against infection with the Omicron strain.

Things that could make you more likely to get a breakthrough infection include:

  • You have a weakened immune system. This could be due to genetics or certain meds, such as chemotherapy or another underlying illness such as HIV.
  • You catch a COVID-19 variant. Research suggests that certain ones might make the vaccines less effective. But getting vaccinated and boosted with the bivalent booster still helps protect you from the variants.

Yes. Certain variants like the Omicron and Delta variants are highly transmissible. Early research from the CDC shows that even if you’re fully vaccinated, it is possible to have a breakthrough COVID-19 infection.

And if you do get infected, it’s possible for you to spread the virus to others. Vaccines against COVID-19 are still the best method available to prevent serious illness and reduce spread.

To limit the spread, the CDC recommends getting the COVID-19 vaccination. Wear N95, KN95, or a properly-fitted cloth mask in indoor public settings, and maintain social distance from others even if you’re fully vaccinated.

If you’ve had mild or moderate COVID-19 infection, the symptoms usually last up to 2 weeks. But for some people, the symptoms can linger long after the infection clears. The symptoms can range from mild to severe. Experts call this Post-Acute Sequelae of SARS-CoV-2 infection (PASC), or long COVID.  Long-COVID symptoms such as loss of smell, cough, fatigue, weakness, shortness of breath, or muscle pain can last 6 weeks or longer.

Although it is uncommon, it is possible to get long COVID from breakthrough infection after being fully vaccinated. Only about 10% of breakthrough cases have been reported to be long-haul.

Some evidence suggests that even if a breakthrough infection makes you sick, your illness may be less severe.

“Fully vaccinated” means you’re getting the most protection you can from your vaccine.

You’re considered fully vaccinated two weeks after you get your second dose of a two-dose vaccine, like the Pfizer, Moderna, and Novavax vaccines.

Your immune system needs those 2 weeks to learn how to fight the virus that causes COVID-19. The CDC recommends getting an mRNA vaccine (Pfizer-BioNTech or Moderna) over the Johnson & Johnson vaccine. But it’s best to get whatever is available near you and follow booster shot guidelines accordingly.

The CDC recommends COVID-19 booster shots for everyone as young as 6 months. The guidelines on which booster to get and eligibility may vary depending on which COVID-19 vaccine you received.

Current CDC guidelines for booster shots:

Pfizer-BioNTech. Everyone 12 years and older can get the Pfizer booster shot 2 months after their initial series of vaccines.

Moderna. If you’re 5 or older, you can get the booster shot 5 months after your last shot.

Novavax. This vaccine is authorized as a 2-dose primary series. a booster dose can be given to those 18 or older after 6 months.

Johnson & Johnson. The CDC recommends that the J&J/Janssen COVID-19 vaccine only be considered in certain situations, due to safety concerns.

If you think you have symptoms of COVID-19 after you’ve been fully vaccinated:

  • Get tested and stay home.
  • Call your doctor if your test result comes back “positive,” which means the test spotted signs of the coronavirus.
  • Ask the doctor how long you should avoid other people, or “self-isolate.”
  • Wear a mask to lower your chances of spreading the disease.

If you don’t have symptoms but a test result shows you have the virus, also stay home, call your doctor, and ask them how long you should self-isolate. They might tell you to wait 10 days since you got your test result.