Moderna Inc. sped up plans for its experimental COVID-19 vaccine on Thursday and said it expected to start a late-stage trial in early summer, pushing ahead in the race for developing a safe and effective vaccine.

The company said it would start a mid-stage trial for the vaccine shortly and Chief Executive Officer Stéphane Bancel said there is potential for a marketing application approval for the vaccine, named mRNA-1273, in 2021.

Shares of the drug developer (MRNA) were up about 8% at $52.81 in midday trade. They have more than doubled in the year.

The company is one of the many healthcare firms attempting to make an effective vaccine for COVID-19 that has killed more than 262,000 people and infected over 3.77 million globally.

There are no approved treatments or vaccines for the respiratory illness, caused by the new coronavirus, though some drugs are being used on patients under an emergency-use authorization.

Moderna previously said it expected mid-stage trials to begin in the current quarter, with the aim to start late-stage studies in the fall.

The company's experimental vaccine is currently being tested in an early-stage trial and Moderna has, so far, made the most headway among companies scrambling to develop a vaccine.

Moderna struck a deal with Swiss contract drugmaker Lonza Group AG last week to speed up manufacturing of the potential vaccine. The company last month also received $483 million funding from a U.S. government agency to accelerate development of the vaccine.

Earlier this week, Pfizer Inc and BioNTech SE said they began delivering doses of their coronavirus vaccines for initial human testing in the United States, hoping to get emergency-use approval in the U.S. as early as October.

Johnson & Johnson plans to start human testing by September, with an eye on having it ready under an emergency-use authorization in early 2021.

No vaccine is expected to be ready for use until at least 2021, as they must be widely tested in humans before being administered to hundreds of millions, if not billions, of people to prevent infection.