Can a Second COVID-19 Vaccine Dose Be Delayed?

Doctor injecting woman with COVID vaccine.

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Key Takeaways

  • According to the Centers for Disease Control and Prevention, one in 10 people missed their second COVID-19 vaccine dose.
  • If a COVID-19 vaccine dose delay is unavoidable, the second dose may be taken up to 42 days after the first.
  • If a person is infected with COVID-19 prior to the second dose, physicians recommend waiting until symptoms have cleared and the infection is over.

In the coming weeks, more than a dozen states will open their COVID-19 eligibility to all adults in an effort to continue curbing the spread and transmission of COVID-19. But while states are working to get first doses in arms, ensuring everyone gets their second dose of the Pfizer and Moderna vaccines can be tricky.

For those who have been vaccinated, the Centers for Disease Control and Prevention (CDC) found that one in ten people missed their second COVID-19 vaccine dose. In the event of an emergency or unforeseen circumstance, some may have to delay their vaccine appointment for the second dose.

“Pfizer’s second injection should be given 21 days after the first one,” Gay Landstrom, PhD, RN, chief nursing officer at Trinity Health, tells Verywell. “For the Moderna vaccine, you should get the second injection 28 days after your first dose.” 

However, you shouldn't worry if you have to delay your second appointment by a few days. The CDC says that in the case that a delay is unavoidable, the second dose can be taken up to 42 days apart. “So this gives a little bit of wiggle room," Landstrom says. "But the ideal is the dates I gave you."

As soon as you find out that you are unable to make your second COVID-19 vaccine appointments, Landstrom says to immediately notify the clinic or pharmacy where you got your first dose. “More often, it requires a phone call to that place," Landstrom explains. "If you got that first dose at a pharmacy, call the pharmacy directly and reschedule that appointment."

What This Means For You

If you need to reschedule your second COVID-19 vaccine dose, notify the clinic or pharmacy where you received your first COVID-19 vaccine dose as soon as possible. The best way to notify them is by calling. When calling to cancel the appointment, experts recommend rescheduling your second appointment immediately as well.

Preventing Vaccine Waste

Because the Pfizer and Moderna vials have expiration dates, it’s best to give a clinic or pharmacy ample notice if you need to cancel or reschedule your second vaccine appointment. “The more notice that an individual can give their pharmacy, their clinic, wherever they’re getting that vaccine, the more it will allow them time to plan," Landstrom says.

Moderna vaccines can be stored in a refrigerator between 36 and 46 °F. If the Moderna vials remain unpunctured, they can last in the refrigerator for up to 30 days. Once Moderna vaccines are punctured, they can be left at room temperature but must be used within six hours.

On the other hand, the Pfizer vaccine is more forgiving. Pfizer vaccines stored in ultra-cold fridges can last up to two weeks. Once thawed, the vaccine may be stored in the refrigerator for up to five days. The Pfizer vials may be returned to an ultra-cold freezer, however, the two-week time frame no longer applies. Therefore, notifying a provider as soon as you are aware of the need to reschedule is crucial in preventing vaccine dose waste. 

But, if circumstances leave you canceling your appointment day-of, you can rest assured there are strategies in place to prevent waste, Landstrom says, like a waitlist of eligible candidates. “If we have somebody cancelled, we’re calling the people who are on the waitlist who meet the eligibility for the vaccine and are willing on short notice to be slotted in so we don’t waste,” Landstrom adds. “It does take some juggling.”

You Will Be Able To Get Your Second Dose After Cancellation

While every clinic and state will have differing policies regarding second doses, Landstrom expresses that at Trinity Health, they try to ensure that a second dose is available no matter the need to reschedule. “I can speak for Trinity Health and the way we have handled it. If we give you your first vaccine, we’re planning to make sure we have a second dose for you,” Landstrom says. “We will make sure that we have a dose available for you.” 

According to Geoffrey Mount Varner, MD, MPH, a physician at John Hopkins Hospital in Maryland, COVID-19 vaccine dissemination requires coordination. “It is a dynamic system, meaning that we’re always getting in more doses," Varner tells Verywell. "And we’re always adjusting how much we can give and how much we can’t."

If a county lacks second doses, Varner says that clinics communicate to transfer available doses between each other. “So just because my county may not have enough doses, I will call the other county to say 'hey, I’m going to need five extra doses,'" Varner says. "And so they’re bringing those five extras.”

It's likely that a vaccination site will work to make your second dose available to you, even if you have to cancel and reschedule.

What if You Get Infected Before Your Second Shot?

Landstrom and Varner both stress that vaccines are not given to active COVID-19 patients. If a person is infected with COVID-19 before the second COVID-19 shot, Varner says that it could be at least two weeks before a person can get the second dose. “It is recommended that you wait until after you’ve cleared your infection,” Varner says.

While unexpected events can happen, Varner suggests people still schedule their second vaccine appointment ahead of time. "I would recommend they schedule that second vaccine while they're getting the first one," Varner says.

As more information about the vaccines and the duration of immunity unfolds, Landstrom stresses the importance of continuing to maintain COVID-19 safety practices.

“It is important to continue to do those things that we have done through the pandemic," Landstrom says. "So even with the vaccine, while it is very effective, it is not 100% effective. And so adding the physical distancing, the washing of hands, the wearing of masks, really help protect people further."

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. Kriss JL, Reynolds LE, Wang A, et al. COVID-19 vaccine second-dose completion and interval between first and second doses among vaccinated persons — United States, December 14, 2020−February 14, 2021. MMWR Morb Mortal Wkly Rep. 2021;70:389–395. doi:10.15585/mmwr.mm7011e2

  2. Centers for Disease Control and Prevention. Moderna COVID-19 vaccine: vaccine preparation and administration summary.

  3. Centers for Disease Control and Prevention. Pfizer-BioNTech COVID-19 vaccine: storage and handling summary.

  4. Centers for Disease Control and Prevention. Prevaccination checklist for COVID-19 vaccines.

By Kayla Hui, MPH
Kayla Hui, MPH is the health and wellness ecommerce writer at Verywell Health.She earned her master's degree in public health from the Boston University School of Public Health and BA from the University of Wisconsin-Madison.