Washington, United States:
US health authorities on Wednesday approved the use of synthetic antibodies developed by AstraZeneca to prevent Covid-19 infections in people who respond poorly to vaccines.
It was the first time the Food and Drug Administration has issued emergency clearance for such a purely preventative treatment.
The FDA warned that the drug Evusheld “is not a substitute for vaccination in individuals for whom vaccination against Covid-19 is recommended” and can only be approved for people with weakened immune systems or for people who cannot be vaccinated for medical reasons, such as a strong allergic reaction.
In those cases, the drug can be administered to people aged 12 years and older.
Evusheld combines two types of synthetic antibodies (tixagevimab and cilgavimab) and is given as two intramuscular injections, one after the other. These antibodies help the immune system fight the virus by targeting the spike protein, allowing it to enter and infect cells.
The FDA said the treatment “may be effective for six months for pre-exposure prevention.”
It cannot be administered to someone already infected with the virus, the FDA said, although AstraZeneca is testing it for such a treatment.
Side effects may include an allergic reaction, bleeding at the injection site, headache, and tiredness.
The FDA authorization was based on a clinical trial conducted in unvaccinated people over 59 years of age, with chronic illness or at high risk of infection.
The drug was given to 3,500 people, while 1,700 were given a placebo. The trial found that the treatment reduced the risk of developing Covid-19 by 77 percent.
Two antibody cocktails, created by Regeneron and Eli Lilly, are currently approved for the prevention of infection in the United States, but only in people who have recently been exposed to the virus, or who are at high risk of exposure, such as employees of old people’s homes or prisons.
In addition to being immunocompromised or unvaccinated, these people must also be at high risk of developing a serious case of the disease.