Johnson & Johnson (J&J) has said that its single-shot Covid-19 vaccine shows strong promise against the Delta variant and other emerging strains and also provides durable protection against the infection more broadly, Reuters reports.

Data shows that the durability of immune response for recipients of its vaccine last at least eight months, the healthcare company has said, adding that its vaccine is 85 per cent effective and can also help prevent hospitalisation and death.

"Current data for the eight months studied so far shows that the single-shot Johnson & Johnson Covid-19 vaccine generates a strong neutralising 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, has said in a statement.