Vials of the Covid-19 vaccines from Pfizer and Moderna, pictured on August 10, 2021 (AFP / HAZEM BADER)
The United States authorized, on the night of Thursday to Friday, the injection of a third dose of Pfizer or Moderna vaccine against Covid-19 for certain people with weakened immune systems.
The US Medicines Agency (FDA) “is fully aware of the fact that immunocompromised people are particularly at risk of contracting serious illness,” said Janet Woodcock, its acting commissioner.
The third dose can be given at least 28 days after the second, to people who have received an organ transplant or those with “a similar level of immunosuppression,” the agency said in a statement.
In contrast, healthy people “do not need an extra dose of the Covid vaccine to date,” Woodcock said.
About 2.7% of American adults, or 7 million people, are immunocompromised, according to the Centers for Disease Control and Prevention (CDC), the country’s leading federal public health agency.
This immune weakness, for example in patients with cancer or AIDS, can come directly from health problems, but also from the drugs they take to solve them. This is the case with transplant recipients, who follow treatments intended to lower the immune defenses to avoid rejection of the transplanted organ.
In these people, the immune response triggered by the vaccine is weaker than in healthy people, which affects its effectiveness.
Covid-19 cases and daily deaths linked to Covid-19 officially recorded in the United States, figures as of August 12 (AFP /)
However, studies have shown that a third dose makes it possible, in certain cases, to increase the protection of immunocompromised against Covid-19.
– Vaccine inequalities –
In a vote, a CDC advisory committee specializing in vaccinations also voted in favor of the decision on Friday. The agency subsequently published its recommendations for healthcare professionals for the administration of this third dose.
During this meeting, health authorities clarified that people who received the Johnson & Johnson single-dose vaccine, a minority in the United States, had not been included in the decision for lack of available data.
According to the CDC, about a million people have already arranged to get a third injection of a messenger RNA vaccine, without being allowed to do so. The director of the agency, Rochelle Walensky, on Thursday asked the population to “follow the recommendations”.
Earlier this month, the World Health Organization (WHO) called for a moratorium on booster doses to fight inequality between rich countries, where vaccines abound, and poor countries, which have failed to immunize. only a small part of their population.
The United States rejected the call, saying it did not “need” to choose between administering a third dose to its citizens or donating it to poor countries.
– Inflection of speech –
Other countries are already authorizing a third dose for immunocompromised people, such as France and Israel, or Germany from September.
These three countries have also announced a booster dose for the elderly. This is not the case with the United States, at least for the moment.
Scientists on the CDC committee will meet again at the end of August to review data on the benefit of an additional dose for other population groups, including “adults over 65, residents of nursing homes. long-term, and health personnel, “according to a presentation by the agency.
Janet Woodcock, Acting Commissioner of the United States Drugs Agency (FDA), July 20, 2021 in Washington (POOL / Stefani Reynolds)
They are the first people to have received the vaccine in the United States. Health authorities want to study whether the level of protection conferred by vaccines erodes over time. But “any decision on recalls will need to focus on preventing severe illness, hospitalizations and death,” said Dr. Sara Oliver, CDC.
“We believe that at one point or another you will need a reminder to ensure the durability of the protection,” Anthony Fauci, White House adviser on the pandemic, said at a press conference Thursday.
“If the data shows us that we need it, we will be ready to do it without delay,” he added.
The rhetoric has therefore shifted since early July, when the FDA and CDC quickly issued a statement assuring that vaccinated Americans “did not need a booster right now”, in response to an announcement by Pfizer that the company would soon seek authorization for a third dose of its vaccine.
Only half of the population is fully vaccinated in the United States, currently facing a surge in the epidemic linked to the Delta variant. After a sharp drop between early April and early July, the pace of vaccination has rebounded slightly in recent weeks.
la / cjc