A second dose of Johnson & Johnson’s COVID-19 vaccine given about two months after the first increased its effectiveness to 94 percent against symptomatic infection, the company said Tuesday.
The company said in a statement that the new data showed that a booster shot could also increase antibody levels and provide better protection against severe disease.
“Our single-shot vaccine generates strong immune responses and long-lasting immune memory. And, when a booster of the Johnson & Johnson COVID-19 vaccine is given, the strength of protection against COVID-19 further increases,” Dr. Mathai Mammen, global head of Janssen Research & Development, said in a statement.
Johnson & Johnson’s vaccine single-dose shot had only provided 70 percent protection.
The drugmaker’s ongoing phase 2 trials showed that the two doses administered about 56 days apart provided 100 percent protection against severe cases and 94 percent protection against moderate to severe infection.
The results put the shot on par with Pfizer and Moderna’s two-dose vaccines, which are 95 percent and 94 percent, respectively, against symptomatic illness.
The company also said a booster given two months after the first dose increased antibody levels four to six-fold. When administered six months after the first dose, antibody levels jumped twelve-fold, data shows.
“This suggests that the efficacy might be even greater when the booster is given at this later point in time,” Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, told ABC News.
The company is now in talks with regulators from the Food and Drug Administration, the European Medicines Agency and others regarding using booster doses of its vaccine.
With Post wires