Edith Arangoitia (46) (who came as a companion of her elderly mother) was vaccinated on February 16, 2021 by La Gabor Harnden at La Colaborativa in Chelsea, Massachusetts, with the Pfizer-BioNTech Covid-19 vaccine.
Joseph Prezioso | AFP | Getty Images
White House medical adviser Anthony Fauci said Monday that Americans should keep two doses of Pfizer and Moderna Covid-19 vaccines, despite a recent U.S. study showing that the shots are very effective after just one dose.
In a disease control and prevention center published last week, a single dose of Pfizer or Moderna’s Covid-19 vaccine was found to be 80% effective in preventing coronavirus infections among healthcare professionals and other emergency workers. Two doses are better than one, federal health officials said, adding that the effectiveness of the vaccines rose to 90% two weeks after the second dose.
Although the 80% figures were good news, Fauci said on Monday he was still concerned about the protection period after a single dose, especially with the emergence of many infectious variants that have shown the ability to evade the protection of the vaccines.
“If you look at the dose after one dose, you can say it’s 80%, but it’s a little 80%,” Fauci said in a White House pandemic newsletter. “If you leave it in one dose, the question is how long does it last?”
Highly contagious Covid-19 variants that have shown some resistance to vaccines are also a challenge, Fauci said. “You’re in a narrow area if you do not have the full impact” of two doses, he said.
Fauci’s remarks come as some health experts and public health officials argue that the U.S. should give priority to Americans just one dose of the vaccines before moving on to second doses, which should accelerate the rate of vaccinations across the country.
Unlike Johnson & Johnson’s vaccine, which requires one dose, Pfizer and Moderna’s vaccines require two shots given three to four weeks apart. In the UK, health officials have decided to extend the time between first and second doses to 12 weeks in an effort to speed up vaccinations.
Fauci has repeatedly said in recent months that the US must adhere to the two-dose regimen.
Dr Paul Offit, a voting member of the FDA’s advisory committee on vaccines and related biological products who reviewed both Pfizer and Moderna’s emergency vaccine, told CNBC last week that studies have shown that immunity after the second time more ‘durable’ seems to be. dose, which means that protection can last longer.
The two-dose vaccine regimen also produces ten times the amount of neutralizing antibodies, which play an important role in fighting the virus, from the first to the second dose, Offit told CNBC.
Second, and more importantly, scientists also detected so-called T cells after the second dose, another important part of the immune response that usually provides longer immunity, he said.
Fauci said Monday he “respects” arguments for a one-dose strategy, but added that the U.S. currently has enough doses to offer Americans first and second doses. “Although we always keep an open mind, we consider the route we are on the best route,” he said.