Breakthrough COVID-19: What to Know

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 12 years old and up.

The COVID-19 vaccines work extremely well. Still, no vaccine is 100% effective. There’s a small 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.

Early data showed that more than half of the people who got breakthrough infections were women.

How Common Is Breakthrough COVID-19?

Early research suggests it’s rare. Two studies suggest that the chance of getting breakthrough COVID-19 is about 0.05%. In both studies, researchers noted that infection happened while COVID-19 cases were surging in the regions where the research took place.

What Can Lead to Breakthrough COVID-19?

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

  • A health care worker accidentally stores or gives the vaccine incorrectly.
  • You have a weakened immune system. This could be due to genetics or certain meds, such as chemotherapy.
  • You catch a COVID-19 variant. Research suggests that certain ones might make the vaccines less effective. But getting vaccinated still helps protect you from the variants.

What Are the Benefits of Full Vaccination?

Some evidence suggests that if 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 and Moderna vaccines
  • Two weeks after you get a single-dose vaccine, like the Johnson & Johnson vaccine

Your immune system needs those 2 weeks to learn how to fight the virus that causes COVID-19.

What Should I Do if I Get Breakthrough COVID-19?

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.

WebMD Medical Reference Reviewed by Brunilda Nazario, MD on May 26, 2021



The New England Journal of Medicine: “Early Evidence of the Effect of SARS-CoV-2 Vaccine at One Medical Center,” “SARS-CoV-2 Infection after Vaccination in Health Care Workers in California.”

CDC: “When You Can be Around Others After You Had or Likely Had COVID-19,” “When You’ve Been Fully Vaccinated,” “COVID-19 Vaccine Breakthrough Infections Reported to CDC -- United States, January 1 - April 30, 2021,” “COVID-19 Vaccine Breakthrough Case Investigation and Reporting.”

AARP: “Can You Catch the Coronavirus After Getting Vaccinated?”

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