By Wendell Roelf CAPE TOWN (Reuters) -A booster dose of Johnson & Johnson Inc’s single-dose COVID-19 vaccine was 84% effective at preventing hospitalisation in South African healthcare workers who became infected as the Omicron variant spread, researchers said on Thursday. The real-world study, which has not been peer-reviewed, was based on a second dose of the J&J vaccine administered to 69,092 workers between Nov. 15 and Dec. 20. An initial course of inoculation has been shown to offer only greatly reduced protection against infection by Omicron, which is spreading quickly through many count…

Read More