American scientists say they may have found the first evidence of a link in humans between certain antibodies and protection from becoming infected with the coronavirus.
The findings — which are not yet peer-reviewed and looked at only a small sample size — come from a case study focused on passengers on a fishing vessel that left Seattle in May.
It examined whether they had a specific type of antibody scientists suspect is linked with coronavirus immunity at the time of departure, and whether they subsequently became infected when an outbreak emerged on board.
Those who tested positive for the antibody in pre-departure tests, the case study states, did not become infected.
The finding is preliminary and while it shows a strong correlation between having the antibody and not getting infected, it does not yet prove causation: that the antibody is the reason for not being infected.
Still, it appears to have sparked some early but cautious excitement online from scientists who say if verified, the findings show for the first time beyond animal studies that there is a connection between having antibodies and virus protection.
Right now, scientists in labs around the world are working on setting up bigger clinical studies looking at how antibodies factor into coronavirus protection — a key part of the search for an effective vaccine.
Antibodies are proteins created by the immune system when it encounters a virus.
They help the immune system defend the body from infections and are the reason vaccines work to prevent illness. By exposing the body to often inert or weaker versions of a virus, vaccination allows the body to develop antibodies and build up a better chance at preventing infection.
In the case of COVID-19, the disease caused by the coronavirus, how that plays out is less clear.
“Because COVID-19 is a new disease, we don’t yet know if the antibodies you create can protect you from a future infection, or for how long this protection might last,” explains the B.C. Centre for Disease Control.
The BCDC says one of the big questions being studied now is whether someone with antibodies can get re-infected with the virus and how long any protective effect lasts.
That has implications for vaccine research in the sense that it is not yet clear whether any vaccine that may be developed will require one dose or multiple doses, and whether those doses will be needed every year, like a seasonal flu vaccine, or last longer, like vaccines for chickenpox or measles.
For now, though, the research continues.