J&J Covid-19 Shots Lasts Up To 8 Months against Delta Variant

The Johnson & Johnson coronavirus vaccine provides immunity that lasts at least eight months, and it appears to provide adequate protection against the worrying Delta variant, the company said in a statement Thursday night (July 7).

The company said one dose of the vaccine elicits both a lasting antibody response and generates immune cells called T-cells that last eight months, also.

Dr. Dan Barouch of Beth Israel Deaconess Medical Center and Harvard Medical School and colleagues tested blood taken from 20 volunteers in an early stage, Phase 1/2 trial of the vaccine.

"Data showed that T-cell responses -- including CD8+ T-cells that seek out and destroy infected cells -- persisted over the eight-month timeframe examined,"

Pfizer/BioNTech and Moderna have both said their two-dose vaccines are protective for at least six months and researchers at Washington University in St. Louis reported earlier this week that their studies of vaccinated volunteers indicate protection from the vaccines should last much longer than that-- even for years. They did not test the J&J vaccine.

Earlier Thursday, J&J said a second or booster dose of its vaccine would not be necessary.