Coronavirus vaccine shows promise

Government-backed coronavirus vaccine shows promise in first human trials

Monday's results "boost confidence" that the company can moved into phase II trials very quickly to determine if the vaccine is effective.

By SARAH OWERMOHLE

Moderna Therapeutics' potential coronavirus vaccine showed promise in its first round of human trials, fueling executives' hopes that it could be ready this year.

All eight patients in a phase I safety trial developed antibodies for the virus after two doses of mRNA-1273, the vaccine that the biotech is developing with the National Institute of Allergy and Infectious Diseases, the agency run by infectious-disease expert Tony Fauci.

Moderna has received $430.2 million from the Biomedical Advanced Research and Development Authority.

Monday's results, although preliminary, "boost confidence" that the company can moved into phase II trials very quickly to determine if the vaccine is effective, executives said on a call with investors. If the next trial goes as expected, the vaccine could begin phase III, the last but most extensive stage of human trials, in July.

Success is not a given. Vaccine development normally takes years, and Moderna has not yet won approval for any vaccine it has developed using the mRNA technology behind its coronavirus vaccine.

The Monday results also show that the highest dose option, 250 micrograms, is not necessary to provoke an antibody response. Patients given 25 and 100 microgram doses still built antibodies for the coronavirus during the month-and-a-half long trial.

That will be key in the future because of how many hundreds of millions of people would need the vaccine if it proves effective in larger studies. "The lower the dose, the more people we expect to protect," said chief medical officer Tal Zaks, noting they expect demand to outstrip supply.

In animal studies done in tandem with the phase I trial, the vaccine completely prevented virus replication in mice lungs, another promising signal. Subsequent trials will study the vaccine's safety, effectiveness and how durable the immune response is to the coronavirus.

Moderna's stock soared 30 percent before the market opened.

Executives said they would defer to NIAID and its academic partners to publish the full results.