Studies indicate J&J COVID-19 vaccine booster protects people against severe illness from Omicron variant

Two reports released Thursday show that people who get booster doses of Johnson & Johnson's Janssen vaccine are well protected against severe disease and hospitalization from the Omicron variant of coronavirus, the company said.

Researchers said the findings indicate that most of the COVID-19 vaccines will protect people against the worst outcomes from infection -- and show some of the emphasis on how the various vaccines affect immune system components called antibodies may be misleading.

One real-life study from South Africa showed vaccine effectiveness against hospitalization from COVID-19 rose to 85% after a booster dose of the J&J vaccine, even after the Omicron variant was circulating. And a lab-based study in the U.S. indicated the vaccine stimulates a strong immune response from cells known as T-cells, which protect people against severe disease even if they don't block the virus entirely from infecting the body.

Results from both studies were released by the company in a statement but are being submitted to a pre-print server and a peer-reviewed journal, the company said.

A team at the South African Medical Research Council helped examine the results of an ongoing study of the J&J vaccine there. They looked at results from 69,000 health care workers. "When a booster shot was administered six to nine months after a primary single dose, vaccine effectiveness increased over time from 63 percent at 0-13 days, to 84 percent at 14-27 days and 85 percent at 1-2 months post-boost," J&J said in a statement.