Why two doses of the new COVID-19 vaccine is more

Pfizer and Modern have enough doses to vaccinate 6 percent of the U.S. population against COVID-19 by the end of the year.

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An Uzbek doctor has prescribed a dose of Pfizer Covid-19 vaccine.

But a simple change would double the number of people getting vaccinated. Instead of receiving two doses, he will be able to get one first in line. A single shot is not as effective, but it does not allow the immune system to defend against some form of coronavirus infection. Spreading supply will provide more protection to millions of people and will probably save more lives in the short term.

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“Everyday mortality at this level is unprecedented,” says Christopher Gill, an infectious disease specialist at Boston University, referring to the current daily mortality rate of Covid-19. It’s time to dump her and move on. “

Moderna and Pfizer are not testing how a single dose of its vaccine compares to two, but experts can read between the lines of available data. The initial shutdown of the Moderna vaccine takes two weeks for an immune response, and recipients receive a booster after 28 days. Over time, the vaccine is 92 percent effective in preventing the pathological COVID-19, writes epidemiologist Michael Meena and columnist Zianp Tufieki. New York Times. After the start of the second dose, the vaccine is 94 percent effective. “The two doses were better, but not surprisingly better,” says Gill. It’s less clear how a single dose of Pfizer vaccine is compared to a double dose, which is 95 percent effective – but Gill says the data suggests that one shot is about 90 percent effective.

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An Uzbek doctor has prescribed a dose of Pfizer Covid-19 vaccine.

Some experts are wary of this proposal, but not because of differences in effectiveness. They cannot prescribe different dosage guidelines without hard evidence. “We don’t know how long or how strong the immune response will be from either one [Pfizer or Moderna] Vaccines, ”Harvard T.H. Barry Bloom, a public health expert at Chan School Public Health, told a news conference.

Without studies, experts cannot predict when a single dose of protection will expire. Below the six-month line, vaccinated people will assume they are safe, they are safe when their protection really works, and health officials will not know it is too late. “If scientists start guessing what the evidence should be, as opposed to creating evidence, it could save more lives in the short term,” Bloom said. “But when it shuts down, we get into a very sticky problem.”

Harvard T.H. William Henaj, an epidemiologist at Chan School Public Health, recommends waiting for a clinical trial to change any dose. “Once we gather evidence, we’ll be in a better position to be able to make that kind of recommendation,” he told a news conference just like Bloom. But Gill, of Boston University, worries that waiting for the trial will cost him his life. “We don’t have the luxury of waiting another six months,” he says. “We have to deal with the information we have.”

If healthcare providers proceeded with a single dose without data to be backed up, Henage expressed fears that people would be more reluctant to get the COVID-19 vaccine. Some are already concerned that companies were speeding up their vaccine tests, and that non-evidence-based vaccine methods could further undermine confidence. And while early vaccine recipients can get a booster when supply is less limited, it’s hard to persuade people to come back for that second shot, especially when follow-up is months or years down. For that, the best way to spread COVID-19 vaccines may be to develop more of them and use them as indicated by their tested labels.