The Biden administration announced the implementation of the booster injection plan on September 20, but this issue is still fiercely debated among experts.
US officials are preparing to implement a booster dose plan, in the context of many studies showing that the vaccine’s ability to protect decreases over time and the number of hospitalizations and deaths increases sharply due to the Delta mutation.
However, they also hope the booster injection plan helps prevent even mild cases. In theory, the booster shot could help reduce the likelihood of infection, though this goal is little talked about by officials, and accelerate America’s recovery.
“It’s not the main reason to get a booster dose, but it can actually be a positive factor,” said Dr. Anthony Fauci, America’s top infectious disease expert and Covid-19 advisor to the Trump administration. President Joe Biden, said.
Fauci said the main goal of the booster dose plan is to reverse the trend of increasing breakthrough cases, the phenomenon of nCoV infection despite having had two doses of the vaccine, an issue many experts are arguing.
Current data indicate that most breakthrough infections with severe symptoms occur mainly in people over 65 years of age and in immunocompromised individuals. These are the two groups where the third dose of vaccine is recommended.
Dr Larry Corey, a virologist at the Fred Hutchinson Cancer Center in Seattle who is overseeing US government-backed Covid-19 vaccine trials, is a proponent of a booster dose to increase antibodies to prevent the risk of infection. chance of viral infection.
“If you don’t get infected, you won’t infect others, and we will be more effective in containing the pandemic. This also has economic benefits,” Corey said.
However, many experts say there is little scientific evidence that the booster dose helps prevent infection and transmission.
Several government studies have shown that when infected with the Delta strain, fully vaccinated people can still transmit the virus, mostly to unvaccinated people. “If you look at the data in the US, it’s clear that the vaccine’s ability is diminishing in terms of preventing infection and mild-to-moderate symptoms,” Fauci said.
This is being recognized in many communities in the US. While 63% of the eligible population in the US has completed the Covid-19 vaccination, the Delta strain is causing a severe outbreak in the unvaccinated group. The two most widely used vaccines in the US today, Pfizer and Moderna, are developed using mRNA technology, both of which are less effective against the Delta strain. The number of infections is also increasing among the vaccinated group, with some hospitalizations and deaths.
The US Food and Drug Administration (FDA) said it will release data on the booster shot ahead of a meeting of its vaccine advisory council on September 17. The expected data includes an announcement on the impact of the booster shot in Israel, where the government closely monitors people who have received the Pfizer vaccine.
During the White House’s weekly Covid-19 meeting, Dr Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC), White House Covid-19 coordinator Jeffrey Zients and Dr. Fauci expressed concern There is concern that reduced immunity to mild and moderate Covid-19 symptoms may lead to reduced protection against severe illness, hospitalization and death.
The debate over booster doses in the US has become the subject of fierce debate among virologists, many of whom do not believe that vaccines are losing their ability to prevent serious illness and hospitalizations.
An article this week in the Lancet by two former FDA vaccine experts and senior World Health Organization (WHO) scientists refuted the arguments for booster injections, saying more is needed. There is a lot of evidence to evaluate and most of the current infections are in the unvaccinated group.
Dr. Paul Offit, an infectious disease expert at the University of Pennsylvania and a member of the FDA’s vaccine advisory board, also said booster doses were unnecessary.
“The question is what is the goal of booster injections? If to increase protection against the risk of severe disease, there is currently no evidence that this is a problem,” Offit said. “If the goal is to increase neutralizing antibody levels to reduce mild or asymptomatic infections, we need to look at that data.”
Corey said that the criteria to prove the vaccine is able to prevent the virus from spreading is very high. “Do we currently have evidence of a vaccine’s ability to prevent infection? The answer is no, but there are reasons to believe it, and it could be beneficial,” he said. .
Fauci said Israel’s data shows that since the launch of the booster injection campaign, the country has reduced the R-factor, the infection rate of the virus. The more immune a community is, the lower the R-factor.
Fauci is baffled by vaccine experts’ arguments about booster shots, which argue that a third shot is needed only when the vaccine no longer prevents severe illness, hospitalization and death.
“What’s so mysterious about hospitalization rates? I don’t get it. They think we don’t care about anything other than stopping people from being hospitalized? They must be joking,” Fauci said.
Thanh Tam (Follow Reuters)