Faced with the slow launch of vaccines, surging Coronavirus disease Death, and the threat of a dangerous variant of the virus spreading across the country, some scientists have called for an urgent reduction in vaccine doses, or a halving in order to vaccinate as many people as possible as soon as possible. But other scientists and U.S. regulatory agencies have postponed the plan, worrying that such plan changes may have disastrous consequences.

The rapid emergence of disagreements caused differences between experts and experts, just as the first Americans who received the COVID-19 vaccine began to receive the vaccine. Their second shot.

Given that clinical trials have been established to test the two-dose schedule, no one can determine the effectiveness or duration of a single dose. To make matters worse, some people worry that giving people partial protection may increase their chances of harm. The virus continues to evolve to resist The role of vaccines.

However, some scientists said that this situation still requires special measures. “When it comes to COVID-19, we have been beaten in the mouth again and again. Now is the time to change the plan,” wrote Ashish Jha of Brown University and Bob Wachter of the University of California, San Francisco. Washington Post editorial On Sunday, it is called for the vaccine to be given to as many people as possible, and to postpone the second injection until more doses are given.

The Director of the US Food and Drug Administration Stephen Hahn and Peter Marks, director of the Institutional Vaccine Center, rejected any changes to the current plan. statement The news released on Monday night said: “At present, it is implied that changes to the dose or schedule of these vaccines authorized by the FDA are too early to take root in the existing evidence.”

Two vaccinesIt is made by Pfizer and the other is made by Moderna. It was approved for emergency use in the United States last month. Large-scale clinical trials have found that when taken separately for three or four weeks, two doses can effectively fight COVID-19 for several months. The FDA’s Hahn and Marks said that the signs of diminished COVID-19 diagnoses among study participants observed between the two doses do not justify a change in schedule. The American Academy of Infectious Diseases supported the FDA’s statement on Tuesday, saying the timetable changes “Premature and potential harm. “

“For some reason, the clinical trial was designed to give two doses on a schedule. This is the data we have.” said Joel Ernst, a vaccine expert at the University of California, San Francisco. “I think the agency [FDA] An operational reality is being injected into interesting and useful scientific discussions, and we should discuss this as well. “

The United Kingdom’s Joint Committee on Vaccination and Immunization (JCVI) overturned the debate last week. Extension of time It takes up to three months to take a second dose of Pfizer vaccine at a time. 1 in 30 Londoners It is believed to be infected with the coronavirus. Most notably, the committee recommends that in emergency situations, if the first shot of the vaccine is not available, or if you don’t know which vaccine to get first, you can use a second dose of a different vaccine.British Society of Immunology Reluctantly supports time changes, There is evidence that, in this case, the highly transmissible variant of the pandemic coronavirus has caused an alarming increase.

Natalie Dean, a biostatistician at the University of Florida, said: “The situation in the UK reflects the emergency situation there.” “If there were no transparent processes from the FDA and CDC that would first lead to vaccine authorization, I don’t see that the United States would do this. change.”

This B.1.1.7 Coronavirus variants, Was first discovered in the UK, because this vaccine is easier to spread, complicating the calculation of how many people need to be vaccinated.Dean said that it has now appeared in more than 30 countries, “In the United States, we have to assume that this variant may be all over.” Although so far only in Four states, Poor genome monitoring In the United States it may mean that it is more common than we currently know. Dean said that even if it is widespread, the current mathematical methods should not be changed by sticking to the current vaccine schedule.

She added that in the coming months, we will better understand the antibodies and immune system cells that provide protection from infection from vaccines. “Once we have these protective relevance, then we can be more confident about any changes in dosage.”

Both Pfizer and Moderna sent BuzzFeed news statements on Monday to support the FDA-authorized second dosing schedule. “Although the decision on alternative dosage regimens rests with the health authorities, Pfizer believes that it is essential to monitor any alternative schedules that have been implemented and to ensure maximum protection for each recipient. This means Two doses of vaccine will be used for immunization,” Pfizer stated.World Health Organization Panel of Experts on Tuesday Support Pfizer’s timeline, But under special circumstances, the second dose can be taken after six weeks.

At the same time, in the United States, Moncef Slaoui, the chief scientist of Operation Twisting, proposed on Sunday to give people two Half dose of Moderna vaccine supply. The National Institutes of Health confirmed that the idea of ??half-dose treatment is being studied on Tuesday. New York Times Report.Sloy suggested expanding the supply, but to some experts’ surprise, his $18 billion in vaccines Private-public partnerships widely acclaimed for quickly advancing vaccine development are under fire for failing to deliver on their promises Provide 20 million photos By the end of this year.They only delivered 17 million and have executed the shooting More than 5 million people As of Wednesday.

Some public health figures such as Jha and Wachter called on the United States to join the United Kingdom to extend the time for the second shot. But in Monday night’s statement, the FDA recommended that this argument overestimated the certainty of effectiveness after an injection.

Ernst said: “We have to realize that every vaccine is different, and we don’t know everything.” “If we know everything, we will get the HIV vaccine 30 years ago.”

For Marc Lipsitch, an epidemiological modelling expert at Harvard University’s TH Chan School of Public Health, the FDA’s status reflects its role as the goalkeeper of new treatments in the United States.

The FDA is a regulatory agency. Broadly speaking, they are not public health agencies-their job is to ensure that what we inject into our bodies and what we take as pills and supplements, and what they advertise and do. In a narrow sense, they are correct. “He said in a briefing on Tuesday.

Lipsitch said: “This is a very interesting case. Regulators think that science, but broadly speaking, the science of public health may be different.”

Many experts have another major concern about the proposal to change the U.S. medication schedule, that states seem to be unable to inject doses that have already been shipped. Generally speaking, the speed of vaccine launch is slower than advertised. There is a big difference from state to state.

Angela Rasmussen, a virologist at the Georgetown Center for Global Health Science and Security, said: “This is basically hitting the ball on the 1-yard line. Dosing schedule, and when I can’t get the vaccine that people have, will I get a limited supply of vaccine? “

Vaccine forecasts have been steadily weakened in this way for several months, starting from OWS until January when the initial pledge of 300 million doses of vaccine was downgraded. Quietly abandoned in August.

George Benjamin, executive director of the American Public Health Association, said: “According to their own predictions, they are behind.” “The truth of the problem is that we always hope for some solutions. These are complex vaccines. But all of these show that We need to manage the shots at a faster speed.”

With the increase of billions of dollars Recently passed spending bill, And the future actions requested by the incoming Biden administration, Benjamin added that the United States needs to switch to 2 million to 3 million vaccine injections per day to reverse the trend of this epidemic. Regarding medication schedules rather than recruiting retired doctors, dentists, and anyone else who can get rid of the dose currently stored on the shelf, this is unrealistic.

“What is the goal? The goal is to stop this pandemic. We need to use all the necessary tools to stop this pandemic.”

Improper gains and losses of the U.S. Senate Vaccine launch funding Jim Blumanstock of the National and Territorial Health Officials Association told BuzzFeed News that until last week, as well as the arrival of storms and holidays, states had been promoting the vaccine to medical institutions that had already handled a large number of COVID-19 cases. He said: “In the final analysis, our broken health care system makes this more difficult.” “The federal government needs to play a bigger role.”

The first stage of vaccination in large medical centers and nursing homes is not a place where most vaccines should be given a few months later.On Tuesday night, the Trump administration said it was accelerating a project aimed at Start getting the vaccine in the pharmacy. The final plan is to follow the flu shot and provide vaccination by the doctor’s office, pediatrician and pharmacy.So far this season, some 71 million flu shots After starting with a small number of people, 8 million injections have been provided to American adults in 15 weeks. In the fall, Amanda Cohn of the CDC warned members of its vaccine advisory group: The first six weeks Before the increase in production, the delivery of COVID-19 vaccine will also be marked by a small number of injections.

Blumenstock said: “If we look at it again in three weeks, the discussion about vaccines may be different.” OWS’ Slaoui has compared the COVID-19 vaccination campaign with the annual flu vaccine and expanded it. Three to four times.

But this sounds optimistic, Walter Orenstein, the former head of the National Immunization Program at Emory University, told BuzzFeed News. He said that people know that the vaccination they will get is much easier than the COVID-19 vaccine. The flu vaccine is just a shot. There are no changing cold chain requirements, more consent requirements and enhanced plans, just like the COVID-19 vaccine we are using now. Orenstein said: “We have never encountered a situation like this before, even compared to the hastily introduced a similar situation.” 2009 H1N1 flu vaccine. The vaccine is not given to yourself. The biggest problem here will be to get people to work together. “

Michelle Dryger, a health communications expert at the University of Manitoba in Canada, said that the real threat of insufficient injections and escalation of vaccine use plans is that public trust in vaccines may decline. In this year’s focus group, she was very worried about taking the new vaccine. Canada’s deployment is similar to that of the United States. The federal government distributes doses to provinces, and each province decides how to distribute their shots.

She said: “I think the FDA’s statement is very clear and effective. This is a good public health message.” “I think at the public level, we need to understand that the agency is doing due diligence.”

Stephanie M. Lee provided coverage for this story.