Can I Test Positive for COVID-19 After Being Fully Vaccinated?

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Key Takeaways

  • It is possible to become infected with COVID-19 after you are fully vaccinated.
  • Fully vaccinated people who get COVID-19 aren't as likely to have severe cases.
  • Booster shots and safety measures like masks offer you extra protection.

Vaccines are not 100% effective in preventing infection. Breakthrough cases are expected, even when vaccines are highly effective.

What Is a Breakthrough Case?

A breakthrough case is when a fully vaccinated person gets the disease they were vaccinated against. Breakthrough cases aren't unique to COVID-19.

Breakthrough Cases Happen

Breakthrough cases occur at low levels with all vaccinations. For example, they occur in children immunized against varicella (chickenpox) and in adults immunized against the flu.

In a March 2021 White House press briefing on COVID-19, Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, explained that breakthrough infections are possible.

“You will see breakthrough infections in any vaccination when you’re vaccinating literally tens and tens and tens of millions of people,” Fauci said.

Milder Symptoms

Sarah McCauley, a nurse from Bethlehem, Pennsylvania, experienced a breakthrough case after being vaccinated.

“I got my first COVID-19 vaccination on December 23, 2020 and received my second vaccination on January 15, 2021," McCauley tells Verywell. "I was tested on March 28 and found out I was positive for COVID-19 on March 30. I have been working on the COVID floor at Lehigh Valley Hospital, but I believe my husband contracted the virus first and passed it to the family. He tested positive along with our oldest son.”

“I was really kind of shocked that I tested positive, and even a little bit frustrated and upset,” McCauley says.

She had headaches, body aches, sinus congestion and pain, and loss of her sense of smell. “Even my teeth and ears hurt,” she says. 

But McCauley believes that vaccination kept her bout with COVID-19 from being severe. Though she has asthma, she didn't have many breathing symptoms.

“I’m feeling OK now," she says. "I just get very tired.”

If you do experience a breakthrough infection, your symptoms are likely to be milder. In most cases, the vaccine prevents people from getting seriously ill or being admitted to the hospital.

What This Means For You

If you've been fully vaccinated against COVID-19, there's still a chance you could contract the virus. The good news is that if you have symptoms, they probably won't lead to a severe case. After vaccination, you should continue to practice safety like masking and distancing to protect yourself and others.

Boosters Are Available

There's evidence that vaccines become less effective against mild or moderate COVID-19 over time. Viruses adapt and change. New strains emerge. As they do, there is a chance that you may be infected with a different strain of the virus. Still, your overall protection is very high.

Booster shots can raise your level of protection. You are still considered fully vaccinated if you don't get a booster shot, but the extra dose will give you added protection for longer.

Stay Cautious

If you have symptoms after you're vaccinated, talk to your doctor and get tested before you go out in public. That could keep you from spreading the virus.

If you have been vaccinated, medical experts say you shouldn't totally let your guard down. It's a good idea to take precautions like these:

  • Wear a mask indoors in public places if you're in an area where COVID-19 tends to spread quickly
  • Stay socially distanced from other people
  • Wash your hands frequently with soap and warm water for at least 20 seconds 
  • Use hand sanitizer when soap and water are not available
  • Live a healthy lifestyle. Eat right, sleep well, move often, and reduce stress

“Don’t assume that just because you’re vaccinated you can’t get COVID-19,” McCauley says. “Err on the side of caution.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. South Carolina Department of Health and Environmental Control. Breakthrough cases: tracking disease infection after vaccination.

  2. Zhu S, Zeng F, Xia L, He H, Zhang J. Incidence rate of breakthrough varicella observed in healthy children after 1 or 2 doses of varicella vaccine: results from a meta-analysis. Am J Infect Control. 2018;46(1):e1-e7. doi:10.1016/j.ajic.2017.07.029

  3. Durviaux S, Treanor J, Beran J, et al. Genetic and antigenic typing of seasonal influenza virus breakthrough cases from a 2008-2009 vaccine efficacy trial. Clin Vaccine Immunol. 2014;21(3):271-9. doi:10.1128/CVI.00544-13

  4. Centers for Disease Control and Prevention. COVID-19 booster shots.

By Donna Siegfried
Donna Siegfried is an award-winning journalist with over 30 years' experience. She is a member of the American Medical Writer’s Association.