news·3 min read

Getting COVID-19 Between Vaccine Shots: Yes, It’s Possible

A woman has her nose swabbed at a Stop the Spread COVID-19 testing site in Massachusetts.
Getty Images
Aug 10, 2021

Nearly 60% of the entire US has gotten at least one COVID-19 vaccine dose. And vaccination rates started to lag once supply outpaced demand in the spring. But as coronavirus cases rise across the country because of the delta wave, vaccination rates have also started to grow as well. So it’s a good time to remind people that you can contract the virus between your first and second doses (if you get Pfizer or Moderna). 

That can happen?

Yes. The CDC considers people fully vaccinated when they’ve hit the two-week mark after their second Pfizer or Moderna dose (or two weeks after a single Johnson & Johnson dose). That’s because it can take weeks for your body to build up immunity. 

In May, the CDC released a study focusing on efficacy rates in vaccinated health care workers. The results? A single dose of Pfizer or Moderna was about 80% effective. For context, the efficacy rate increases to about 95% for both of these shots after a second dose.

Which brings us to an important fact: while they’re rare, breakthrough cases exist. That’s when a fully vaccinated person contracts the virus. If that happens to you – or if you’ve been exposed to COVID-19 after getting your shots – here’s what you should do.

Yikes. What should I do if I get sick between my shots?

Quarantine at home, rest, talk to your doctor, and take care of yourself. Experts say you should finish isolating and fully recover before getting your second dose so you don’t risk spreading the virus. Depending on how mild or severe your case is, that may take between 10 and 20 days.

Next: figure out if you need to reschedule your second dose. If there’s enough time for you to fully recover before your next dose, then you should be good to go. If not, call up your vaccination site or see if you can pick a new date online. And try to reschedule it for as early as you can. 

Will delaying my shot change its effectiveness?

Not necessarily. The CDC has previously said that you can delay your second dose up to 42 days after the first dose. Some countries like Canada and the UK delayed giving people second doses for 12 to 16 weeks in an effort to get as many people a first dose as quickly as possible – but the US hasn’t followed their lead, instead focusing on getting people fully protected ASAP.  Either way, experts say it’s important to go back to get the second shot to keep yourself as protected as possible.


The vaccination campaign in the US has been a roller coaster ride. Part of that is the fact that it’s possible to contract COVID-19 during (and even after) the vaccination process. No matter where you are in the process, it’s helpful to continue to practice safety measures like wearing a mask and social distancing to help prevent you and others from getting sick, especially as variants like delta continue to spread.

Updated on August 10 – Updated to include the latest information on vaccination rates, breakthrough cases, and delaying vaccine shots.

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