CHICAGO - Johnson & Johnson (J&J) recently mentioned that the second dose of its COVID-19 vaccine, which was given two months after the first, increased the vaccine effectiveness to 94 per cent compared to 70 per cent with the first one.
The data showed increased effectiveness of second shots in the United States against moderate to severe forms of COVID-19.
J&J, the only drugmaker with a single shot COVID vaccine in the United States, had been under pressure to show evidence on the effectiveness of additional doses to be considered for a booster shot.
J&J said a booster given two months after the first shot increased antibody levels four to six times and when given after six months after the first, antibody levels shot up twelve-fold. Hence showed an increased improvement in protection with the longer interval between doses.
