UPDATE 1-Pfizer plans to test COVID-19 vaccine booster targeting the South African variant Reuters 2/18/2021 By Michael Erman NEW YORK, Feb 18 (Reuters) - A top Pfizer Inc scientist said on Thursday the company is in intensive discussions with regulators to test a booster shot version of its coronavirus vaccine specifically targeted for a highly contagious variant that is spreading widely in South Africa and elsewhere. A laboratory study released on Wednesday suggested that the South African virus variant may reduce protective antibodies elicited by the Pfizer/BioNTech vaccine by two-thirds, but it is not clear how much that reduces the shot's effectiveness against this version of the pathogen.