Johnson & Johnson announced Tuesday that its booster shot increases protection to 94% against the coronavirus when it is given two months after the first dose.
"When a booster of the Johnson & Johnson COVID-19 vaccine was given six months after the single shot, antibody levels increased nine-fold one week after the booster and continued to climb to 12-fold higher four weeks after the booster. All rises were irrespective of age," the American pharmaceutical company said in a statement.
Global research head Mathai Mammen said the company's single-shot vaccine generates strong immune responses and long-lasting immune memory, adding when the booster is given, the strength of protection further increases.
"A single-shot COVID-19 vaccine that is easy to use, distribute and administer, and that provides strong and long-lasting protection is crucial to vaccinating the global population," said Chief Scientific Officer Paul Stoffels.
The company said it has provided data to the US Food and Drug Administration and plans to submit it to other regulators such as the World Health Organization and National Immunization Technical Advisory Group.
The pandemic has claimed more than 4.7 million lives in at least 192 countries and regions since December 2019, with over 229.2 million cases reported, according to the US-based Johns Hopkins University. Vaccine doses administered total more than 5.95 billion, it showed.