J&J's COVID-19 Booster Shot 85% Effective Against Hospitalization, In South Africa Phase 3 Study

(RTTNews) - Johnson & Johnson's (JNJ) COVID-19 booster shot has provided strong protection against the Omicron variant, and reduced the risk of hospitalization, as per preliminary results from the South African Phase 3b Sisonke study.

The study results showed that a homologous (same vaccine) booster shot of the Johnson & Johnson COVID-19 vaccine (Ad26.COV2.S) demonstrated 85 percent effectiveness against COVID-19-related hospitalization.

The study showed that the Johnson & Johnson booster reduced the risk of hospitalization from COVID-19 among healthcare workers in South Africa after Omicron became the dominant variant.

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.

Separate analysis of the immune response to different vaccine regimens demonstrated that a heterologous booster (different vaccine) of the Johnson & Johnson COVID-19 vaccine in individuals who initially received the BNT162b2 mRNA vaccine generated a 41-fold increase in neutralizing antibody responses and a 5-fold increase in CD8+ T-cells to Omicron by four weeks following the boost.

A homologous boost with BNT162b2 generated a 17-fold increase in neutralizing antibodies and a 1.4-fold increase in CD8+ T-cells by four weeks following the boost. Both neutralizing antibodies and CD8+ T-cells were higher four weeks after the boost with the Johnson & Johnson vaccine than with the BNT162b2 vaccine.