CHICAGO, September 15 (Hfrance.fr) - US officials prepare to deploy COVID-19 booster injections in the face of declining vaccine protection and increased hospitalizations and deaths by the highly contagious virus The Delta variant is hoping that the boosters could prevent mild cases as well.
In theory, this could reduce the transmission of the virus - a goal on which those responsible have been less explicit - and accelerate America 's recovery.
"This is not the main reason (for boosters), but it could actually be a very positive offshoot, " Dr. Anthony Fauci, one of the Biden administration 's COVID-19 advisers and the nation ' s top infectious disease physician, adreported to Hfrance.fr.
The main reason for the recalls, Fauci said in a telephone interview, is to reverse the trend 'increase in "breakthrough" infections among fully vaccinated people, a point that many experts dispute.
Available data has shown that the most severe breakthroughs have occurred in people over 65 years of age or in those who are immunocompromised. The latter group is already recommended for a third dose.
Dr. Larry Corey, a virologist at the Fred Hutchinson Cancer Center in Seattle who oversees U.S. government-backed COVID-19 vaccine trials, advocates the use of booster doses to raise antibody levels enough to prevent infection. 'infection.
"If you are not infected, you will not pass it on to others,and we will abort the epidemic more effectively, and that has economic benefits, "said Corey.
The problem, according to many experts, is that there is little scientific evidence to show that boosters will actually prevent infection and transmission.
Some government studies have shown that when they are infected with the Delta variant, fully vaccinated people can transmit the virus, mainly to unvaccinated people.
"If you take a look at the evidence from the United States, it is very clear that protection against infection and mild to moderately symptomatic disease is waning, "Fauci said.
This occurs among many populations studied in the United States, including a recent study of 600,000 cases of COVID-19 in 13 states and major cities. "Not dramatically, but enough ", he said.
'WHAT IS THE GOAL? '
While about 63% of eligible people in the United States are fully vaccinated, the Delta variant has caused an increase in fatal disease among unvaccinated.
The two most widely used vaccines in the United States - those based on messenger RNA (mRNA) technology manufactured by Pfizer Inc (PFE.N) with BioNTech SE and Moderna Inc (MRNA.O ) - are very effective but less effective against Delta. Cases are increasing among those vaccinated - including some resulting in hospitalization and death. The US Food and Drug Administration will release data on a possible booster injection Wednesday morning before a Friday meeting of its vaccine advisory committee. It will include an impact briefing boosters in Israel , where the government closely followed the recipients of the Pfizer / BioNTech shot.
During weekly briefings at the House Blanche on COVID-19, the U.S. Centers for Disease Control and Prevention (CDC) Director Dr. Rochelle Walensky, Jeffrey Zients and Fauci, White House COVID-19 response coordinator, have expressed concern over the fact that decreased immunity to mild and symptomatic COVID-19 could lead to reduced protection against serious illness, hospitalization and death, citing data from Israelël.
Other countries that have started or are planning recall programs, including Israel - and the UK for people over 50 years - has been more outspoken about the goal of reducing transmission.
The booster dose debate in the United States has become one sore point for virologists, who remain largely convinced that vaccines lose their ability to prevent serious illness and hospitalization.
This week, an article in the Lancet journal written by two FDA vaccine experts and senior scientists from the World Health Organization, challenge to justify booster doses , saying that more evidence is needed to justify their widespread use and that most cases of COVID-19 are propamanaged by unvaccinated people.
Dr. Paul Offit, an infectious disease expert at the University of Pennsylvania and a member of the FDA's Vaccine Advisory Board, is not convinced by the arguments that boosters are needed at this time.
"The question is, what is the purpose? If the purpose of the third dose is to improve protection against serious illness, it doesn 't 'There is no evidence that this is a problem, "Offit said. If the goal is to increase the levels of neutralizing antibodies in order to decrease asymptomatic symptoms or mild cases, " then we should see this data. "
Corey said the bar for proving that a vaccine prevents disease transmission is high.
"Is there any proof today? No, but there is every reason to believe that it is possible, and possibly beneficial, "he said.
Fauci, however, said Israeli data shows that since the start of The recall campaign, the country began to see a decline in the virus "reproduction number, which represents the number of other people a person will be likely to infect with COVID-19. The more immune a population is, the lower the reproduction number.
Fauci said he was baffled by arguments from vaccine experts that boosters are only needed when vaccines stop preventing serious illness, hospitalization, and death.
"What's the magic, mystical question about hospitalization? I don't understand that, "he said. "What we're really saying is that we don't care about anything except keeping people out of the hospital. Really? Are you kidding me. Report by Julie Steenhuysen; Additional reporting by Nandita Bose in Washingtong; Edited by Caroline Humer and Bill Berkrot
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