"The antibody cocktail, derived from the blood of COVID-19 patients in Israel, is a safe natural substance," TAU said.

The researchers said that since the antibodies are natural and remain stable in the blood, one injection can be protective from COVID-19 for several weeks, or even several months.

In their study, led by TAU and published in bioRxiv preprint platform, the researchers proved the effectiveness of the antibody cocktail in cell cultures, while the next stage will be a clinical trial in humans.

The researchers sequenced thousands of antibodies, and consequently, they were able to isolate and characterize six antibodies derived from the blood of two severely ill patients.

Then, they proved that combinations of three antibodies at a time act as an effective cocktail against COVID-19, providing natural immunity for up to several months.

The team found that the blood's capacity for neutralizing the virus comes from several types of antibodies that simultaneously attack different areas on the virus, and that the cocktail is effective in neutralizing the COVID-19 virus.

The study also found that people with mild symptoms or asymptomatic COVID-19 developed a weaker antibody reaction, and therefore may contract the disease again.

In contrast, all severely ill patients analyzed by the researchers developed neutralizing antibodies that are likely to protect them from reinfection.