CLEVELAND, Ohio – The second dose of Pfizer’s COVID-19 vaccine should be delayed to stretch supplies, as one shot almost as well as two protects against serious cases, two researchers in Canada wrote in a letter in the New England Journal has been published. of medicine.
Pfizer’s response to the researchers’ letter, which was also published in The New England Journal of Medicine, said that ‘alternative dosing regimens’ for the vaccine had not yet been properly evaluated.
“The decision to introduce alternative dosing regimens rests with health authorities,” Pfizer said. “However, we at Pfizer believe that it is critical for healthcare authorities to oversee implemented alternative dosing schedules to ensure that vaccines provide the maximum possible protection.”
Researchers Danuta Skowronski and Gaston De Serres analyzed the data Pfizer submitted to the Food and Drug Administration and determined that the first dose of the vaccine had an efficacy rate of approximately 92.6%.
The Pfizer vaccine, administered in two doses 21 days apart, has an effectiveness of 94.8% against COVID-19 after two doses.
Dr. Anthony Fauci, the leading American expert in infectious diseases, recently said on NBC’s “Meet the Press” that he does not agree with experts requesting a delayed second dose. More research is needed to measure the long-term protection that people get with just one shot, he said.
“The amount of time it will take, the amount of people you will have to spend on the study – by that time we will already be in the arena to have enough, to have enough vaccines anyway,” Fauci said.
Given the relatively small increase in the efficacy rate between the first and second doses, the authors argued in the letter that ‘the benefits of a rare amount of vaccine can be maximized by postponing second doses until all members of the priority group at least offered. a dose. ”
So far, health experts have encouraged the public to obtain both doses of Pfizer and Moderna vaccines for maximum protection against COVID-19.
The letter advocating a single shot comes as public health experts discuss whether the second dose of COVID-19 vaccines should be delayed so more people in high-risk categories can get their first shot earlier.
The Canadian researchers acknowledged that while there may be ‘uncertainty about the duration of protection with a single dose’, the second dose weeks after the first ‘offers a little extra benefit in the short term, while high-risk individuals taking a first dose with the vaccine stock is left completely unprotected. ”
The first dose of Pfizer or Moderna is ‘quite impressive’, said Dr. Bruce Vanderhoff, chief medical officer of the Ohio Department of Health, said during the COVID-19 briefing of Government De Mike Mike.
“They do generate very significant levels of antibodies and show fairly significant ability to prevent humans from developing COVID diseases,” Vanderhoff said of the vaccinations.
Someone can get COVID-19 between the two doses. But the second dose increases more than just the antibody. It triggers the adaptive immune system. It is a large cellular part of the immune system.
“This is important because it is what allows the endurance of the vaccine,” he said.
And it causes a lithe immunity he calls, which helps protect against the coronavirus variants.
‘Both [doses] needed, ”Vanderhoff said. “The first one is very good. But you are not done with the first one. ‘
A growing number of countries are considering postponing the second dose of COVID-19 vaccines to maximize the number of people getting their first chance.
Health experts in France are discussing whether people who have recovered from COVID-19 should give only one dose of vaccine instead of two to release doses for others.
The World Health Organization said in January that the “second dose of the Pfizer vaccine could be given under” exceptional circumstances “up to six weeks after the first dose.
The US Centers for Disease Control and Prevention recommends that you take the second dose of Pfizer vaccine as close to schedule as possible. The experts said the vaccines were approved on the basis of clinical trials, and the clinical trials did not take into account the consequences of a significant delay.