Researchers from Oregon State University observed that two cannabis compounds, CBGA (cannabigerolic acid) and CBDA (cannabidiolic acid), are able to block SARS-CoV-2 from entering cells. By attaching themselves to spike proteins on the virus, the compounds block an important step in the infection process.
This does not mean smoking weed will prevent COVID-19. The purity of the tested compounds was higher than that available in commercial products. In a separate study, THC (tetrahydrocannabinol), the psychoactive component of cannabis, did not keep the virus out of cells, and even blocked the therapeutic effect of CBD when combined with the non-psychoactive compound.
Scientists emphasize that more research must be done to corroborate the findings.