Johnson & Johnson (J&J) and Moderna recently announced promising results in studies to determine vaccine effectiveness against the highly contagious Delta variant of the coronavirus.

First identified in India, Delta is becoming the globally dominant variant of the coronavirus, according to the World Health Organization.

Johnson & Johnson said late Thursday that its single-shot COVID-19 vaccine showed strong promise against the variant and other emerging strains and also provided durable protection against the infection more broadly. Earlier in the week, Moderna said its vaccine showed promise against the variant with a modest decrease in response compared to the original strain.

J&J said its data showed that the durability of immune response for recipients of its vaccine lasted at least eight months, adding that its vaccine was 85 percent effective and could also help prevent hospitalization and death.

“Current data for the eight months studied so far shows that the single-shot Johnson & Johnson COVID-19 vaccine generates a strong neutralizing antibody response that does not wane; rather, we observe an improvement over time,” Mathai Mammen, head of research & development at J&J’s drugs business, said in the statement.

Meanwhile, Moderna’s study was conducted on blood serum from eight participants obtained one week after they received the second dose of the vaccine. It provoked an antibody response against all the variants tested, according to Moderna, but one that remained inferior in all cases to the vaccine’s neutralizing activity against the original coronavirus strain first found in China.

The vaccine was far more effective in producing antibodies against the Delta variant than it was against the Beta variant first identified in South Africa, the data showed.

“These new data are encouraging and reinforce our belief that the Moderna COVID-19 vaccine should remain protective against newly detected variants,” company Chief Executive Stéphane Bancel said.

The Delta variant contributed to a surge in COVID-19 cases in India that resulted in the highest daily death tally in the world, and also prompted the U.K. to delay its reopening by one month in June.

J&J and Moderna have submitted data as a preprint to the website bioRxiv ahead of a peer review. Pfizer announced its vaccine was highly effective against COVID-19 variants, including Delta, through study results last month.

— Reuters and staff