Should you or shouldn’t you? Many of us have asked ourselves these questions for months as we debated getting the COVID-19 vaccine. Now that we have braved the needle and started searching for flight deals, it is being discovered that our newfound freedom is quickly being taken away.

The CDC has announced that there have been instances where COVID vaccinated persons have still contracted the virus.

These rare cases are now being called “breakthrough cases.”

So this brings us to the question, can you get COVID after being fully vaccinated? The answer is yes!

“You will see breakthrough infections in any vaccination when you’re vaccinating literally tens and tens and tens of millions of people. So in some respects, that’s not surprising,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said at a March 26 White House COVID-19 briefing.

Read what can lead to a breakthrough case, according to AARP:

  • Imperfect vaccine administration. It’s rare, but if the vaccine is mishandled, it could cause a breakthrough case. Maybe the vials aren’t kept at the required temperature, the vaccine is administered to the wrong part of your arm, or you don’t get a full dose. In February, for example, a CVS pharmacy in Massachusetts issued an apology because it inadvertently gave some patients only a partial dose.
  • An individual with a weak immune response. With every vaccine, there is a small subset of people who don’t develop a robust immune response, says Chris Woods, an infectious disease physician and executive director of the Hubert-Yeargan Center for Global Health at Duke University. It could be the result of medications that weaken the immune system (such as chemotherapy for cancer) or genetic differences. Although age is also thought to weaken the immune response, the clinical trials for the COVID-19 vaccines show high efficacy rates in older adults.
  • New coronavirus strains or variants. Early data indicate the current COVID-19 vaccines should work against known coronavirus variants that are more infectious. But it’s possible that a variant could elude some of the protection we get from vaccination, Poland says. Fauci has said it’s important to sequence the genome of the virus in the breakthrough cases to find out whether each infection is from the original virus strain or a variant. Meanwhile, vaccine manufacturers are already working on changes to provide better protection against variants.