WASHINGTON, Feb 10 (Reuters) - Novavax Inc said on Thursday (Feb 10) its two-dose vaccine was 80 per cent effective against COVID-19 in a late-stage trial testing the shot in teens aged 12 to 17 years.

The trial involved 2,247 adolescents and took place between May and September last year when the Delta variant was the dominant strain in the United States. The vaccine was 82 per cent effective against the variant.

The U.S biotech said it expects to submit applications to global regulators for the shot's use in adolescents during the first quarter.

Novavax late last month filed for authorisation of the shot in US adults, a much-awaited step following months of struggles with development and manufacturing problems.

The vaccine has received authorisations from the European Union and the World Health Organization and has been cleared for use in adults in countries including the United Kingdom and New Zealand.

In the company's trial in adults, which enrolled about 30,000 participants in the United States and Mexico, the vaccine had an efficacy of 90.4 per cent.