In a new study, researchers found that pairs of antibodies may be more effective than single antibodies at preventing and treating COVID-19.
The study also suggests that in addition to blocking SARS-CoV-2’s entry into cells, the antibodies may combat the virus by enlisting various types of white blood cells to fight the infection.
The research was conducted by a team at the University of North Carolina at Chapel Hill and The Rockefeller University in New York.
Human antibodies that neutralize SARS-CoV-2 hold great potential for preventing and treating COVID-19.
Researchers have identified several potent antibodies that bind to the spike protein on the virus’s surface, thereby preventing it from mediating the virus’s entry into cells.
However, the neutralizing activity of antibodies to SARS-CoV-2 has primarily been tested using cells cultured in the laboratory, and how these in vitro results translate to protection in animals or humans has not been determined.
In the study, the team tested the ability of several human antibodies to prevent SARS-CoV-2 infection in mice or hamsters.
Surprisingly, they found that certain antibodies were more potent than expected.
Some antibodies that were relatively poor at blocking viral entry into cultured cells were much more effective at preventing SARS-CoV-2 infection in rodents.
The researchers found that this is partly because, in addition to blocking viral entry, the antibodies can activate various types of white blood cells.
These “antibody effector functions” help the immune system target the virus and/or virally infected cells.
The team also found that antibodies maybe even more effective when used in combination with each other.
Pairs of antibodies that target slightly different parts of the viral spike protein could successfully prevent or treat SARS-CoV-2 infection in mice and hamsters at much lower doses than single-antibody treatments.
This is a particularly useful approach because targeting multiple parts of the spike protein reduces the chance of the virus mutating and becoming resistant to antibody treatments.
The team says some antibody combinations can be effective for prevention and early therapy of SARS-CoV-2 even at relatively low doses.
Overall, the findings support the idea that specific combinations of antibodies with the ability to activate immune cells should be developed for optimal protection and therapy against SARS-CoV-2.
One author of the study is Timothy P. Sheahan, an assistant professor.
The study is published in the Journal of Experimental Medicine.
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