Scientists warn that Americans are over-expecting the COVID-19 vaccine

The White House and many Americans have fixed their hope of defeating the COVID-19 pandemic with a vaccine being developed at “Warp Speed.” But some scientific experts warn that they are all expecting too early and too much.

“Everyone thinks COVID-19 is no longer a vaccine,” said Dr. William Haseltine, chairman and president of Access Health International, a foundation that advocates affordable care.

Ongoing clinical trials Mainly designed Indicates whether it is a COVID-19 vaccine Prevents symptoms of illness — May be minor, such as a sore throat or cough. However, a study investigating 30,000 to 60,000 volunteers can prove that vaccines prevent people from being hospitalized or dying by the time the first vaccine maker applies for an emergency. , The period is too short and the size will be too small. According to Haseltine, the authorization will take place later this year.

Haseltine argued that the United States should refrain from optimal vaccines with more proven competence. Others have killed at least 225,000 Americans The devastating victims of the pandemic will accept the best vaccine the country can achieve in the coming months, even if serious questions remain after its release. Says to request.

“There is a tension between getting all the information and getting the vaccine. [out] In time to save lives, “said Dr. William Schaffner, a professor of preventive medicine and health policy at Vanderbilt University Medical Cancer.

“Do you want to know if vaccines reduce illness and mortality? Of course,” said Dr. Peter Lurie, a former FDA employee and now director of the Center for Public Interest Sciences. “But there is real-time pressure. This is a pandemic. It’s explosive.”

Researchers discussed how rigorously the COVID-19 vaccine will be tested on Thursday Public meeting of Food and Drug Administration Advisory Board on Vaccines..

“Preventing mild cases may not be enough to justify the risks associated with vaccination,” said Peter Dosi, an associate professor of pharmacy at the University of Maryland. BMJ editorial.

However, vaccine experts say there is good reason to focus on mild cases of COVID-19.

Dr. Arnold Mont, an epidemiologist at the University of Michigan’s School of Public Health and an extraordinary chairman of the Vaccine Commission, said vaccines that prevent mild illness usually also prevent severe illness.

For example, in the first study of measles vaccine, prevention of measles alone did not prevent hospitalization or death, said Dr. Kathleen Neuzil, director of the University of Maryland’s Vaccine Development and Global Health Center. ..

Subsequent studies have shown that the measles vaccine dramatically reduces mortality. According to the World Health Organization, the worldwide death toll from measles decreased by 73% between 2000 and 2018 due to vaccines.

Dr. Philip Krause, Deputy Director of the Vaccine Office at the FDA’s Center for Biologics Evaluation and Research, said: “There is no example of vaccine science that works for mild illness and not for severe illness. At a hearing on Thursday.

Dr. Paul Ofit, who developed the rotavirus vaccine, compared the prevention of coronavirus with the fight against fire.

“If you put out a small fire in the kitchen, you don’t have to worry about a fire in your entire house,” said a member of Ofit. FDA Advisory Board on Vaccines..

Proving that a vaccine prevents severe illness or death is more difficult than showing that it prevents mild illness because hospitalizations and deaths are much rarer. This is especially true among health-conscious people who volunteer to test vaccines. They probably wear masks more than others and are more likely to be socially distant, Schaffner said.

“When we looked at the hospitalization of older people with the flu, it was a two-year trial,” Neuzil said. An ongoing study, “Investigating typhoid vaccines in nearly 30,000 children,” is a two-year trial.

The COVID-19 pandemic officially infected about 8.7 million Americans. Dr. Ameshua Darja, a senior scholar at the Johns Hopkins University Center for Health and Security, said the mortality rate was estimated to be 6 to 10 times higher than the actual number of infected Americans reported. He said it was about 0.6%.

Dr. Corey Casper, a vaccine scholar and chief executive officer of infectious diseases at the Fred Hutchinson Cancer Research Center, agrees that the ideal vaccine provides “bactericidal immunity.” This means preventing not only the symptoms of the disease, but also the infection by the virus. Seattle Institute.

For example Two doses of measles vaccine Prevents 97% of people from getting the virus.

Few people expect the COVID-19 vaccine to be so effective. “We’re trying to lower that standard to determine how low and acceptable it is,” Casper said.

Preventing mild illnesses can help control and prevent illnesses, Casper said.

“We probably won’t get the perfect vaccine,” he said. “But if you can show that it’s safe, you’re likely to have a vaccine that can put an inflection point in this pandemic …. Get a vaccine that works for mild illnesses. I think that is still important. “

According to Casper, flu shots are less effective, ranging from 19% to 70% each year, but still very useful.

During the 2018-19 flu season in the United States, vaccination prevented an estimated 4.4 million flu illnesses, 2.3 million consultations, 58,000 hospitalizations and 3,500 flu-related deaths. Centers for Disease Control and Prevention..

Trials of 30,000 to 60,000 people are already quite large by historical standards. Dramatically increasing the size beyond that is not practical in a compressed time frame, Klaus said.

“If the endpoint of the study is a serious illness, the study may need to be nearly 10 times larger,” he said at the conference. “And those tests are infeasible and never vaccinated.”

“If you have a vaccine that is highly effective or appears to be life-saving, and if it is very likely to save your life, you don’t want to stop it,” Klaus said. ..

Coronavirus vaccine trials measure serious illness or mortality, but these are “secondary endpoints” and the current size of the study is large enough to generate statistically significant answers. It means that it is not.

According to Neuzil, whether the vaccine will reduce serious illness and mortality will be revealed in studies after the vaccine has been distributed.

Mr. Ofit said the discussion revolved around one question.