What Happens If I Get COVID-19 Between Vaccine Doses?

Someone receiving a vaccine injection.

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Key Takeaways

  • You are not considered fully vaccinated if you have only been administered one dose of the Pfizer-BioNTech or Moderna vaccine.
  • If you get COVID-19 after your first vaccine dose, you need to isolate for 14 days after your potential exposure to someone with COVID-19.
  • Reschedule your second dose after you have recovered from COVID-19, ideally as close to the originally-planned date as possible.

If you’ve only had your first dose of a two-dose COVID-19 vaccine (Pfizer-BioNTech or Moderna), it’s important to remember that you aren’t as fully protected as possible against COVID-19 just yet. With that in mind, is it possible to contract COVID-19 between the two doses? Experts say yes, although CDC data shows it happens in fewer than 2% of cases.

You are only considered fully vaccinated two weeks after your second dose, and until then, you haven’t reached the full level of protection the vaccine can provide.

“It is possible to get COVID-19 between the first and second doses of the mRNA vaccines, and some people have,” William Moss, MD, MPH, executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health in Maryland, tells Verywell.

Getting COVID-19 between doses doesn’t mean that you need to restart the series or forego the second dose altogether. Here’s what you need to know about rescheduling your second dose.

Vaccines Don't Completely Prevent COVID-19

Although the vaccines provide a high degree of immunity against SARS-CoV-2, the virus that causes COVID-19, they aren't 100% effective. It’s still possible for fully vaccinated people and those who have yet to receive their second dose to get COVID-19. 

Based on clinical trials, the Pfizer-BioNTech vaccine is 95% effective at preventing COVID-19. The Moderna vaccine is 94.1% effective.

“Centers for Disease Control and Protection (CDC) reported that among 2,479 individuals who were fully vaccinated with two doses of mRNA vaccines, there were three SARS-CoV-2 infections, whereas among 477 individuals with only one dose of mRNA vaccine, there were eight confirmed SARS-CoV-2 infections,” Inci Yildirim, MD, PhD, vaccinologist and pediatric infectious diseases specialist at Yale Medicine in Connecticut, tells Verywell.

Although you need both doses of a two-dose vaccine series to be fully vaccinated, the first dose does already provide considerable benefit in reducing the risk of severe disease. “The first dose should provide some protection, particularly against severe COVID-19," Moss says. "So your symptoms should be less than someone who was not vaccinated at all."

Isolate and Reschedule Your Second Dose

If you get COVID-19 before your scheduled appointment for the second dose, you need to reschedule and recover first. It’s important that you isolate for 14 days after your most recent potential exposure to someone with COVID-19.

“Available data from clinical trials indicate that those who had SARS-CoV-2 infection can safely get COVID-19 vaccines," Yildirim says. "CDC recommends deferring vaccination until the individuals recover completely and they have completed their isolation period. Rescheduling the second dose may be needed, but testing is not recommended."

Individuals with underlying immunosuppressive diseases should check in with their healthcare providers regarding these recommendations, she adds.

After recovering from COVID-19, you still need to get the second dose of the vaccine to gain its full protective benefit, since it's still unknown how long protection developed after natural infection will last. Experts say you don’t need to restart the vaccine series, but the second dose should be administered as close as possible to the recommended interval of 21 and 28 days after the first dose for the Pfizer-BioNTech and Moderna vaccines, respectively. 

“If this is not feasible, CDC recommends the second dose of either vaccine can be administered up to six weeks after the first dose,” Yildirim says. There isn’t much research about the effectiveness of the vaccines if the second dose is administered beyond the recommended six weeks, so it's best if you stay within that time frame.

However, there’s a caveat to this rule. “If you were treated with monoclonal antibodies or convalescent plasma when you had COVID-19, you should wait 90 days to be vaccinated,” Moss says.

This is a precautionary measure set by the CDC because there is limited research on the potential interactions of antibody therapy with the immune response from the vaccine. If you already had your first dose, got COVID-19, and were treated with antibody therapy, you need to wait 90 days before getting the second dose.

Some individuals may be concerned about the effect of COVID-19 on vaccine efficacy, but it’s unlikely that efficacy will decrease if you get infected between doses.

“Studies looking at the antibody levels after vaccination among individuals with prior laboratory-confirmed SARS-CoV-2 infection showed that previously-infected persons had higher levels of vaccine-induced antibody response compared to those without a history of SARS-CoV-2 infection,” Yildirim says. “We still need to determine how these levels impact the vaccine-induced protection and how long it will last.”

What This Means For You

If you get infected with COVID-19 before you get your second dose of the Pfizer-BioNTech or Moderna vaccine, you need to isolate for 14 days after your potential exposure to someone with COVID-19. Reschedule your appointment for no later than six weeks after the date of your first shot. You should still complete your vaccine doses even if you've recovered from infection.

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.

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  1. Thompson MG, Burgess JL, Naleway AL, et al. Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers — eight U.S. locations, December 2020–March 2021. MMWR Morb Mortal Wkly Rep. 2021;70:495–500. 10.15585/mmwr.mm7013e3

  2. Centers for Disease Control and Prevention. Pfizer-BioNTech COVID-19 vaccine overview and safety. Updated April 5, 2021.

  3. Centers for Disease Control and Prevention. Moderna COVID-19 vaccine overview and safety. Updated April 5, 2021.

  4. Centers for Disease Control and Prevention. When to quarantine. Updated March 12, 2021.

  5. Centers for Disease Control and Prevention. Interim clinical considerations for use of COVID-19 vaccines currently authorized in the United States. Updated March 5, 2021.