One of the leading coronavirus experts is delaying his second dose of the vaccine. Should you do the same?

delaying second dose of vaccine
Photo via New York National Guard/Flickr (CC BY ND 2.0)
  • This story is regularly updated for relevance. Last updated: June 22, 2021

Although COVID cases and death rates in the U.S are way down, there are still some concerns about a possible uptick in the coronavirus between the emerging B.1.1.7 variant strain and with many states loosening their restrictions. One leading epidemiologist believes the solution could be delaying a second dose of the vaccine for millions of Americans.

However, he warns, we’re running out of time to act. But not everybody believes you should follow what he does.

To prove his point, Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, is delaying his own second shot of the vaccine—banking not just his credibility but potentially even his health.

Osterholm believes the key is protecting as many people as possible, particularly Americans 65 years and older who are more likely to experience severe illness and hospitalization due to the virus. Though 80% of COVID-19 deaths occur in this age group, only about 41% of people 65 and up have been vaccinated.

“Imagine I’m sitting on one side of the table, and I have two doses of vaccine, one in each hand,” Osterholm explained in a March 8 interview with New York Magazine.

“On the other side of the table is my mom and my dad, or my grandpa and my grandma. And they both are over 65, they both have an underlying health condition. And I’m gonna look them in the eye and say, OK, I can give both doses to one of you, or I can give one dose to each of you,” he continued.

“What would you like me to do? Wouldn’t you want, particularly with evidence of the protection we have, to protect both of them, and not leave one totally vulnerable?”

Osterholm and his colleagues have come up with a few different scenarios in which to maximize vaccinations. For one, he questioned why people who have already had COVID-19 are receiving two shots when there is already “compelling data” that a single dose provides an excellent response. He also believes administering half-doses would be an ideal way of stretching out doses, given that results were the same in gauging effectiveness for both full and half doses in the Moderna vaccine trial.

Another viable alternative, he said, would be delaying second doses of the Pfizer and Moderna vaccines until after the potential surge, when the U.S. expects to have enough doses to vaccinate all adults in the country. Evidence suggests that delaying your second dose of the vaccine has no impact on the overall effectiveness. In fact, ongoing scientific trials seem to indicate that waiting a few more weeks might even allow your immune system to better respond to the virus.

“These studies were never set up to measure, ultimately, your immune response or dosing,” Osterholm said. “They were set up so that you could get a product approved quickly with authorization.”

Furthermore, Osterholm said that a single dose of the mRNA vaccines seems to offer at least the same protection as the single-dose vaccine from Johnson & Johnson. He finds it perplexing that one vaccine would be approved for one dose while the others require two—both with about the same results. 

Data from the single Johnson & Johnson vaccine points to increased protection over time, and Osterholm believes the same would be true of Moderna or Pfizer. However, neither of those trials studied the long-term effects of a single dose.

“There is sufficient data to support that, at least for the short term, you clearly have enough protection against serious illness, hospitalizations, and death,” said Osterholm. “So, it’s a bit disingenuous for people to say we have all the science based on the submission of the vaccines for approval. There’s much, much more that’s come out.”

Further backing Osterholm’s theories are findings by a preliminary study recently conducted by AvonCAP, an ongoing surveillance project funded by Pfizer Inc. Evidence found that just one dose of the Pfizer or Oxford-AstraZeneca vaccines “significantly reduces the risk of hospitalization for COVID patients in their 80s with preexisting health conditions.”

The study learned that one dose of Pfizer vaccine was 71.4% effective at preventing symptomatic illness severe enough to require hospitalization after 14 days in patients with a median age of 87. A single dose of the Oxford-AstraZeneca vaccine was found to be 80.4% effective after 14 days in patients whose median age was 88.

So, is delaying your second dose of the vaccine the right move?

Whether people should follow Osterholm’s lead is a different story, as the question of delaying second doses is “sharply divided” among health and science experts. 

The Advisory Committee on Immunization Practices (ACIP), a committee within the Centers for Disease Control and Prevention, said on March 8 that the data on changing doses is too limited to make new recommendations at this time. Advisers also worry that it’s too soon to tell if a single dose is enough to protect against the virus’ variant strains.

That hasn’t reportedly stopped about 5 million people (or 8% of people who were vaccinated) from skipping their second dose (it might because a decent amount of people are confused about whether they need it).

Without a sweeping federal guidance and recommendation, the likelihood of changing behaviors and attitudes about holding off on a second dose of the vaccine seems slim.

“You have to walk the talk and talk the walk,” said Osterholm, on his decision to delay his second dose. “I would be a hypocrite if I didn’t believe that vaccine wouldn’t provide me adequate protection through this surge.”

“I just know that there are thousands of grandpas and grandmas, moms and dads, brothers and sisters that could be protected with a single dose,” he added. “If we keep up doing what we’re doing, they’re not going to have that chance before this surge comes.”

Here’s something else to consider. As the delta variant of the coronavirus becomes more prevalent in the U.S., the Pfizer vaccine is about 88% effective against that version of the virus if the recipient gets two doses. After just one dose, it only offers 33% protection.

In mid-June, the vice president of the Australian Medical Association said those who didn’t get the second dose of the AstraZeneca vaccine were “almost wasting the first dose.”

Read more on the coronavirus vaccines:

Sources: New York Magazine, US News & World Report

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