What happened

Shares of Moderna (MRNA 1.90%) climbed 15.4% in July, according to data provided by S&P Global Market Intelligence, as the company advanced its coronavirus vaccine program.

Several factors helped push the stock higher throughout the month. Moderna published interim results from the phase 1 study of its vaccine candidate in The New England Journal of Medicine. Though the company released a summary in May, the most recent report included additional details.

For example, Moderna reported neutralizing antibody activity in all participants after two vaccine doses. Neutralizing antibodies have the ability to block infection, so they are seen as key in the development of a successful coronavirus vaccine. In Moderna's earlier summary, results on neutralizing antibodies were only available for eight trial participants.

A researcher holds up a dose of vaccine and a syringe.

Image source: Getty Images.

Moderna shares also climbed in July as the company's coronavirus vaccine candidate entered a phase 3 trial. And finally, comments from Dr. Anthony Fauci about the possibility of one or more vaccine candidates showing safety and efficacy in the coming months offered a boost for companies testing potential vaccines.

So what

Moderna's shares gained 228% in the first half of the year on optimism about its coronavirus vaccine work. Back in March, the company became the first to begin human trials. But as other companies joined the race and quickly advanced their programs, Moderna found itself sharing the spotlight. It is among six companies involved in phase 3 testing at the moment.

The detailed trial data as well as the move into late-stage testing reassured investors about Moderna's prospects of winning the vaccine race, or finishing among the top players.

Now what

Moderna said on Wednesday that it's on schedule to complete phase 3 trial enrollment in September. The company plans to offer an update at that point. It also spoke of pricing, saying it has so far signed supply agreements in the range of $32 to $37 per dose.

Investors should remain focused on trial data and should pay particular attention to the vaccine candidate's performance in older adults. So far, reported data concerns trial participants ages 18 to 55. Since that time, Moderna has enrolled older and elderly participants in trials for the investigational vaccine. The elderly have been among the most vulnerable to the coronavirus, so it's particularly important to see how the vaccine performs in this age group.

Trial data as well as any funding or supply agreement news likely will determine the direction of this biotech's shares in the weeks to come.