Booster shot of Johnson & Johnson’s Covid-19 vaccine increases levels of antibodies sharply

American pharmaceutical company Johnson & Johnson said that a booster shot of its Covid-19 vaccine sharply increased levels of antibodies, according to interim data from two early-stage trials. A second dose of the United States company‚Äôs single-dose vaccine resulted in binding antibody levels nine times higher than the levels 28 days after people received their […]