New antibody cocktail 100% effective in blocking symptomatic COVID-19 infections

"This is the first treatment shown to prevent COVID-19 after a known exposure, and offers protection for unvaccinated individuals caring for a family member with COVID-19," said UVA Health's Dr. William Petri Jr., one of the researchers leading the UVA trial.

The interim clinical trial data was released by the antibody cocktail's manufacturer, Regeneron Pharmaceuticals.

The antibody cocktail is currently in the Phase 3 trial, which aims to determine if the antibodies can block COVID-19 in those who've been exposed to the virus but haven't developed the disease yet. This process is called passive immunization.

According to Petri, Regeneron would request emergency use authorization from the Food and Drug Administration to prepare the antibody cocktail for use within weeks.

"The general idea is that an ounce of prevention is better than a pound of cure, so that's what this study is doing. It's giving the antibody as soon as there's a potential exposure to prevent household transmission," explained Petri.

He also said this antibody cocktail is the only treatment that could prevent COVID-19 symptoms as well as infections after exposure to the virus.

"It sort of gives your immune system a head start," Petri further said, explaining about the antibody cocktail.

"You'll eventually make these antibodies anyway, but by giving them very early, even at the time that you're exposed to the infection, they've been shown to prevent symptoms of COVID-19. They also prevent infection in about half of the patients that receive them," he said.

Moreover, the antibody cocktail is expected to block variants of coronavirus by using two different antibodies.

"Two different antibodies against two different variants of the spike-like protein, that's much harder for the virus to mutate around, and so I think that's probably part of the reason why it's so effective," Petri explained.

However, it's not a vaccine and isn't expected to offer permanent immunity.

Interestingly, clinical trials show the antibody cocktail also limits the amount of virus transmission as well as the length of infection, thereby reducing the amount of time that the virus can spread from one person to another.

"Where the antibody cocktail failed to prevent infection, the infection is much shorter-lived, it's much less virus, and no symptoms, at all, most importantly," Petri said.

As mentioned earlier, though the cocktail might not provide full immunity against COVID-19, it can work along with vaccines to prevent its spread and harmful effects.

"Even when we get the vaccines to everyone...there are still going to be people who were not vaccinated or didn't have a response to the vaccine...there will always be a place for this kind of therapy," Petri stated.