LONDON (Reuters) — British drugmaker AstraZeneca has begun testing an antibody-based cocktail for the prevention and treatment of COVID-19, adding to recent signs of progress on possible medical solutions to the disease caused by the novel coronavirus.

The London-based company, already among the leading players in the global race to develop a successful vaccine, said the study would evaluate if AZD7442, a combination of two monoclonal antibodies (mAbs), was safe and tolerable in up to 48 healthy participants between the ages of 18 and 55 years.

If the UK-based early-stage trial, which has dosed its participants, shows AZD7442 is safe, AstraZeneca said it would proceed to test it as both a preventive treatment for COVID-19 and as medicine for patients who have it, in larger, mid-to-late-stage studies.

AstraZeneca shares were up about 1% at $114 in early trading.

Development of mAbs to target the virus, an approach already being tested by Regeneron, ELi Lilly, Roche and Molecular Partners, has been endorsed by leading scientists.

mAbs mimic natural antibodies generated in the body to fight off infection and can be synthesized in the laboratory to treat diseases in patients. Current uses include the treatment of some types of cancers.

AstraZeneca in June received $23.7 million in funding from U.S. government agencies to advance development of antibody-based treatments for COVID-19.

“This combination of antibodies, coupled to our proprietary half-life extension technology, has the potential to improve both the effectiveness and durability of use in addition to reducing the likelihood of viral resistance,” said Astra’s executive vice president of biopharmaceuticals R&D Mene Pangalos.

Though vaccines are at the heart of the long-term fight against the pandemic, alternative treatments are also being advanced, and the United States on Sunday authorized use of recovered COVID-19 patients’ plasma to treat those who are ill.