A laboratory study suggests that the South African variant of the coronavirus may reduce antibody protection from the Pfizer Inc.-BioNTech SE vaccine by two-thirds, and it is not clear if the shot will be effective against the mutation, the companies said on Wednesday.

The study found the vaccine was still able to neutralize the virus and there is not yet evidence from trials in people that the variant reduces vaccine protection, the companies said.

Still, they are making investments and talking to regulators about developing an updated version of their mRNA vaccine or a booster shot, if needed.