What if my second COVID-19 vaccine dose is rescheduled or delayed? Expert says grace period exists

DeKALB – One northern Illinois doctor is reassuring the public that it’s not the end of the world if your second COVID-19 vaccine dose isn’t administered within the established 21-day window.

Dr. Irfan Hafiz, an infectious disease specialist and chief medical officer at Northwestern Medicine Hospitals in Huntley, McHenry and Woodstock, said manufacturers do give recommendations on what the ideal time span is between the first and second doses of the vaccine. He said the Pfizer vaccine’s recommendation is 21 days, while Moderna’s is four weeks.

“From [Centers for Disease Control and Prevention] guidance, there’s a little bit of leeway that you could do it up to four days earlier than what’s manufacturer recommended,” Hafiz said. “But it shouldn’t go any sooner than that.”

The bottom line is that you don’t want to go get that second dose too early, he said, but it’s unlikely anyone would need a third dose for that reason.

What if my second vaccine appointment needs to be rescheduled because of inclement weather or supply shortages?

Hafiz said vaccine effectiveness shouldn’t be impacted if your second dose is administered a little later, whether because of bad weather or scheduling conflicts. Moderna’s, for example, has a grace period of up to 42 days between doses instead of the recommended 30, he said.

“It doesn’t have to be exact,” Hafiz said. “It’s preferred – I think the vast majority should try and get it on that date – but if for other reasons, if you had to be a little flexible, you could move it out just a little bit.”

Do I need the second dose? What’s the difference in immunization effectiveness with one or two if I can’t get the second dose?

Even though doctors prefer single-dose vaccinations, Hafiz said, it’s recommended that for the COVID-19 vaccine, two doses are needed for optimal immunization.

Due to the virus’ ever-evolving nature, having just one dose may not elicit the desired response rate of communal inoculation, or provide patients the fullest benefit of vaccine. That’s why spreading out dose No. 1 and 2 is so instrumental, he said.

“By getting it a little sooner, your body may have not been quite that ready to respond, and you may not get the full antibody response that you’d like,” Hafiz said. “So that timing is, for that reason, important there.”

Although unlikely, what should I do in the event my second dose appointment is rescheduled or canceled and not administered within the grace period for vaccine effectiveness?

Although it’s rare, Hafiz said, he urges a patient who already got first dose but can’t get the second dose despite the grace period to contact their physician. He said those patients may have to restart the vaccine series and get a third dose, depending on whether the patient is under active medical care or has a chronic disease, for example.

What’s the likelihood that I’ll have an allergic or adverse reaction to the first dose and not be able to get the second?

Hafiz said there were some allergic reactions reported in initial Pfizer and Moderna vaccine trials of about 40,000 patients, and any reaction warranting medical attention remains a concern for medical professionals.

“However, now, with more widespread use, the last I saw there were over 25 million, closer to 30 million people already vaccinated,” Hafiz said. “So we are tracking through the national … database the amount of reactions that have occurred … and the numbers are really small.”

How small? Hafiz said there have been 2 1/2 allergic reactions out of one million doses reported, according to the CDC.

“It’s pretty rare to see that,” Hafiz said.

What is expected is a fair number of people developing symptoms such as body aches, arm soreness and chills, Hafiz said. He said he personally had some chills the first night after getting the second dose of the vaccine – and taking some Advil to help manage those symptoms did the trick for him.

“That’s your body responding to that,” Hafiz said. “It’s not an allergic reaction, it is not necessarily a side effect – it is your body responding to that.”

Hafiz said some people may not have any side effects at all to either dose of the vaccine. He said that doesn’t necessarily mean the patient already had the virus or that it’s otherwise a cause for concern about whether they’re adequately protected.

“It doesn’t mean they’re not responding to it,” Hafiz said. “It just means that your body didn’t feel it necessary to respond that way.”

Hafiz said patients definitely can take nonsteroid medications like Advil or Tylenol after getting vaccine to help manage symptoms, since it should not interfere with the effectiveness of the vaccine. He said it really shouldn’t matter whether you take those over-the-counter drugs before or after getting the shot, since it’s not blocking the body’s specific response pathways for this vaccine.

I can’t seem to secure a vaccine appointment anywhere. What should I do?

Hafiz said he believes there’s a lot of anxiety from people about trying to get the vaccine. He said he’s hoping to see wider availability in the next month or month and a half.

“Just reassurance that, everyone be calm, it is coming,” Hafiz said. “I am very optimistic that we will see increased availability though the health department, through other pharmacy retailers, health systems – whatever demographic you fit in, we should be able to get the vaccine out to you soon.”