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Scientists and government debate on coronavirus vaccination

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Faced with slow vaccine launches, surge Coronavirus disease With deaths and the threat of a dangerous variant of the virus spreading across the country, some scientists have called for the vaccine dose to be halved or postponed in order to vaccinate as many people as possible as soon as possible. But other scientists and U.S. regulatory agencies are fighting back, worrying that such plan changes may have disastrous consequences.

Just as the first Americans vaccinated against COVID-19 began to accept this rapidly growing disagreement, there are disagreements between experts and experts Their second shot.

No one knows exactly how effective a single dose is or how long it lasts, because clinical trials are set up to test two-dose dosing regimens.Worse, people worry that giving people only partial protection may increase Viruses evolved to resist The effect of the vaccine.

However, some scientists said that this situation requires extraordinary measures. “When it comes to COVID-19, we have been slapped again and again. It’s 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 called for the vaccine to be given to as many people as possible, and to postpone the second injection until more doses were injected.

US Food and Drug Administration Director Stephen Hahn and Institutional Vaccine Center Director Peter Marks rejected any changes to the current plan. statement The news released on Monday night stated that “at this time, it is too early to recommend changes to the dose or schedule of these vaccines authorized by the FDA, and it is not firmly rooted in the existing evidence.”

Two vaccinesOne is produced by Pfizer and the other is produced by Moderna. It was authorized for emergency use in the United States last month. Large-scale clinical trials have found that the protective effect of two doses on COVID-19 can last for several months if they are administered three to four weeks apart. The FDA’s Hahn and Marks said that the signs of diminished COVID-19 diagnoses among study participants seen between the two doses do not justify changing the schedule. The American Academy of Infectious Diseases supported the FDA’s statement on Tuesday, saying that the planned changes “Premature and possibly harmful. “

1) If we want to generate difficult virus escape mutants in the laboratory (for example for epitope mapping), we put the virus under low antibody pressure and then slowly move upward. It’s a bit like after a dose of vaccine. I think it would be good to give the second dose as soon as possible.


Twitter: @florian_krammer

“For some reason, the clinical trial aims to provide two doses as planned. This is the data we have,” said Joel Ernst, a vaccine expert at the University of California, San Francisco. “I think the agency [FDA] A dose of operational reality is being injected into interesting and useful scientific discussions, and we should have such discussions. “

The Joint Committee on Vaccination and Immunization (JCVI) approved last week Extension of time Extend Pfizer’s second dose of vaccine to up to three months 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 dose of vaccine is unavailable, or if you don’t know which vaccine was given first, you can use a second dose of a different vaccine.British Society of Immunology Reluctantly support time changes, Cited evidence that a more spreadable variant of the pandemic coronavirus is behind the surge in cases there.

“What is happening in the UK reflects the emergency situation there,” said Natalie Dean, a biostatistician at the University of Florida. “Without the transparent procedures of the FDA and CDC, I would not be able to see the U.S. make this change, which firstly led to the approval of the vaccine.”

This B.1.1.7 Coronavirus variants, First discovered in the UK, complicates the calculation of how many people need to be vaccinated because it is easier to spread. Now seen in more than 30 countries, “In the United States, we have to assume that this variant may be over,” Dean said.Although so far only Four states, Poor genome monitoring In the United States, this may mean that it is more common than we currently know. Dean said that even if it is widespread, it should not change the mathematics of sticking to the current vaccine plan.

She added that in the next few months, we will gain a better understanding of antibodies and immune system cells from vaccines that can provide protection from infection. “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-approved second dosing plan. “While the decision on alternative dosing regimens is made by the health authorities, Pfizer believes that it is essential to monitor any alternative schedules implemented and to ensure the maximum possible protection for each recipient, which means two doses Vaccine,” said Pfizer statement.World Health Organization Panel of Experts on Tuesday Support Pfizer’s timeline, But said that under special circumstances, the second dose can be given up to six weeks later.

At the same time, in the United States, Moncef Slaoui, the chief scientist of Operation Warp Speed, proposed to give people two Half dose of Moderna vaccine Stretching supplies. The National Institutes of Health confirmed on Tuesday that the half-dose idea is under investigation. New York Times ReportHowever, Slaoui’s suggestion to expand the supply surprised some experts because of his $18 billion in vaccines Public-private partnerships widely acclaimed for quickly advancing vaccine development come under fire for failing to deliver on promises 20 million shots By the end of this year.They only delivered 17 million and they have already given injections More than 5 million people As of Wednesday.

Some public health professionals, such as Jha and Wachter, called on the United States to work with the United Kingdom to extend the time for the second injection. But in a statement on Monday evening, the FDA stated that this argument exaggerated the certainty of effectiveness after a single injection.

“We must realize that every vaccine is different, and we don’t know everything,” Ernst said, calling for caution. “If we knew everything, we would get the HIV vaccine 30 years ago.”

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

“The FDA is a regulatory agency. Broadly speaking, they are not a public health agency-their job is to ensure that we inject into ourselves and take things as pills and supplements, and whatever they advertise. In a narrow sense, , They are right,” he said at a press conference on Tuesday.

Lipsitch said: “This is a very interesting case. Regulators’ view of science may be different from the broader scientific view of public health.”

Peter Aldhous / BuzzFeed News / Via covid.cdc.gov

As of January 6, the doses of vaccines administered by the states.

Another major concern that many experts suggest to change the US dose schedule is that states seem to be unable to inject the doses that have already been shipped. The introduction of vaccines has generally been slower than advertised. The huge difference between state and state.

“It’s basically a spike on the 1-yard line,” said Angela Rasmussen, a virologist at the Georgetown Center for Global Health Science and Safety. “Why should we fundamentally fix the proven effective dosing regimen-I know that our vaccine supply is limited-when we can’t put the supply we have into people’s arms?”

For several months, vaccine forecasts have been steadily declining in this way. This is a forecast since OWS downgraded the 300 million doses of vaccine originally promised. Quietly abandoned in August.

Taking a single dose will destroy the last remaining credibility of OpWarpSpeed. If you look at the published data, you can find that only 2 doses of both mRNA vaccines can provide reasonable virus neutralizing antibodies. And only 2 agents can protect https://t.co/r1InUWmTES


Twitter: @PeterHotez

Georges Benjamin, executive director of the American Public Health Association, said: “According to their own predictions, they are behind.” “The truth of the matter is that we have been expecting some shocks. These are complex vaccines. But all All these indicate that we need to inject at a faster rate.”

With the increase of billions of dollars Recently passed spending billBenjamin added that, as well as the future demanded by the incoming Biden administration, the United States needs to take action to inject 2 million to 3 million vaccines per day to reverse the trend of the pandemic. Arguing about dosing schedules rather than recruiting retired doctors, dentists, and anyone else who can try to take out the doses that are now on the shelf is irrelevant.

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

CDC / ACIP / pass Centers for Disease Control and Prevention

The CDC predicts that within five weeks of its launch, 10 million doses of vaccine will be distributed every week.

The U.S. Senate failed to properly Vaccine launch funding Jim Blumenstock of the Association of State and Territory Health Officials told BuzzFeed News that until last week, with the arrival of the storm and the holiday season, it had been launched in medical facilities handling a large number of COVID-19 cases Vaccines are hindered. “In the final analysis, our fragmented health care system makes this all the more difficult,” he said. “The federal government needs to play a bigger role.”

The first stage of vaccine promotion takes place in large medical centers and nursing homes, rather than where most vaccinations take place a few months later.Late on Tuesday, the Trump administration said it was speeding up a plan Start vaccinating in the pharmacyThe final plan is to follow how to get the flu vaccine, and immunizations will be provided by the doctor’s office, pediatrician and pharmacy.So far this season, some 71 million flu shots It has been injected into American adults within 15 weeks, and after starting a small number, more than 8 million injections have been given in a few weeks. In the fall, Amanda Cohen of the Centers for Disease Control and Prevention warned members of its vaccine advisory group that The first six weeks The introduction of the COVID-19 vaccine was also marked by a small number of injections, and then increased.

“If we watch it again in three weeks, our conversation about vaccines might be different,” Blumenstock said. Slaoui of OWS compared the COVID-19 vaccination campaign with the annual influenza vaccination campaign, which has expanded three to four times in size.

But this sounds optimistic, Walter Orenstein of Emory University, former director of the National Immunization Program in the United States, told BuzzFeed News. He said that flu vaccination is much easier than COVID-19 vaccination, and people know what they are getting. The flu vaccine is just a shot, there are no cold chain requirements, more involved consent requirements and enhancement plans, which can be seen in the COVID-19 vaccine we currently have. “We have never encountered such a situation,” Orenstein said, even with the hasty launch 2009 H1N1 flu vaccine“Vaccines will not be given to themselves. The big problem here is getting people to work together.”

Michelle Driedger, a health communication expert at the University of Manitoba in Canada, said that the real threat of inadequate vaccination schedules and interruption of vaccine schedules is that public trust in vaccines may decline. In this year’s focus group, she found a lot of concerns about taking the new vaccine. Canada’s launch is the same as that in the United States. The federal government allocates doses to provinces, and each province decides how to distribute the vaccine.

“I think the FDA’s statement is very clear and effective. It is an excellent public health message,” she said. “I think at the public level, we need to understand that the agency is doing due diligence.”

Stephanie M. Lee reported on this story.


January 7, 2021 at 17:26 PM

correct: Angela Rasmussen works at the Center for Global Health Science and Safety in Georgetown. An earlier version of this article misreported her institution.



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