- Dr. Anthony Fauci warned on Monday against postponing the second shots of COVID-19.
- He said it could be a recipe for new variants to spread, giving people weaker immunity.
- While one shot gives “some” protection, the data suggests that two shots are “ten times” better, said Fauci.
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Dr. Anthony Fauci said that ensuring that people in the U.S. receive their second dose of a Pfizer or Modern COVID-19 vaccine in time can be extremely important in containing the rise in new variants of rapidly spreading viruses.
Fauci, the director of the National Institute of Allergy and Infectious Diseases, said that while it is true that a single injection can “give a degree of protection” to people, it does not seem nearly as strong as the powerful shield against disease that two injections provide.
That is why he is not recommending giving more Americans the first doses of vaccines and waiting until the end of the year to give people their second “boost” injection, a strategy that is now being tested in the UK.
This plan, while it may be successful in partially protecting more people more quickly, is very risky and is not backed by any of the data we have so far, he said.
“The way viruses respond to pressure, you may be inadvertently selecting more mutants,” said Fauci on Monday during a coronavirus meeting at the White House. “For that reason, we continue to believe that we feel that the ideal approach would be to continue receiving as many people as possible on the first dose, but also ensuring that people – at the right time – receive the second dose.”
2 shots provide stronger protection against all forms of the virus, including variants
Fauci has already taken his two shots.
Patrick Semansky-Pool / Getty Images
Vaccine tests on tens of thousands of volunteers around the world have shown how authorized Pfizer and Moderna vaccines work as a two-dose course when given 21 days apart (for Pfizer) or 28 days apart (for Moderna) .
Given this way, these vaccines appear well over 90% effective in ending symptomatic coronavirus infections. (AstraZeneca’s dual vaccine, which is authorized for use in the United Kingdom, but not yet in the United States, appears less effective than that of Pfizer and Moderna.)
Two injections of the Pfizer or Moderna vaccine, when given on time, can provide “ten-fold” immune protection from an injection, said Fauci.
“The reason this is important is not just because of the height of the response and the potency of the response, but as you reach that level of antibody, you get a greater range of response,” added Fauci.
This “breadth” of the virus’s response can be extremely important in helping to contain the pandemic, especially now.
“By breadth of response, we mean that it covers not only the wild type and the virus currently in circulation, but also the variants we see circulating, particularly 1.1.7 and 3.5.1”, added Fauci, referring to the variants identified by first time in the United Kingdom and South Africa, respectively.
In other words, as vaccines do not work so well against the new variants, it is important to ensure that the coverage we get from them is as robust as possible, and the way to do this is to apply two full doses to people.
It seems increasingly likely that variant B.1.1.7 will become the dominant strain of the virus transmitted in the United States in March, said Fauci – a timeline that aligns with recent forecasts by other experts.
It is not yet clear whether we could ‘get away with a single dose’
A nurse prepares a coronavirus vaccine developed by the National Institutes of Health and Moderna Inc.
Hans Pennink / AP
Fauci said it was still “not irrational” to ask whether people would be able to “get away with a single dose” of Pfizer or Moderna vaccines, at least for a while.
But he emphasized that there were no finished studies on the effectiveness of this one-shot strategy. By the time that rigorous testing on the issue could be completed, there would be a better supply of vaccines to circulate across the United States anyway, making it a “moot point” for the study, he said.
The strategy can also be dangerous.
An injection of the Moderna or Pfizer vaccine will provide a lesser degree of infection-fighting power than two full doses. As a result, Fauci said, giving people just one dose can turn their vaccines into easier-to-fight threats to the virus, allowing it to learn to mutate faster and better and continue to infect more vaccinated people.
The important thing, said Fauci, is “to vaccinate as many people as quickly as possible” with two injections.
“This is the best defense against the evolution of variants,” he said.