Johnson booster 85% effective against Omicron: S.Africa study
The South African Medical Research Council conducted the study on health workers from November 15 to December 20, but it has still not been peer-reviewed.
It found the top-up jab to largely protect staff in a country where the highly transmissible strain is now behind most Covid cases.
"Data from the... study confirm that the Johnson & Johnson COVID-19 booster shot provides 85 percent effectiveness against hospitalization in areas where Omicron is dominant," Johnson & Johnson said.
"This adds to our growing body of evidence which shows that the effectiveness of the Johnson & Johnson Covid-19 vaccine remains strong and stable over time, including against circulating variants such as Omicron and Delta," it said.
Around half a million South African health staff have received Johnson jabs as part of clinical trials.
Africa's hardest-hit country, South Africa has recorded more than 3.4 million cases and 90,000 deaths since the start of the pandemic.
An earlier South African study in December found the Pfizer/BioNTech vaccine to be less effective overall against Omicron, but still prevented hospital admissions by up to 70 percent.
© 2021 AFP