CAMBRIDGE, Mass. (WPRI) — After vaccine-maker Pfizer announced Monday its COVID-19 vaccine candidate is more than 90% effective, another vaccine candidate hit a major milestone and is closing in on another.

Massachusetts-based Moderna says its finished data for the first analysis of its vaccine and expects to have an announcement about how effective its vaccine is sometime this month.

The company reported it reached an important mark with its study participants.

In order for Moderna’s vaccine to even be considered for authorization by the U.S. Food and Drug Administration, the company says at least 53 study participants needed to become ill with COVID-19.

Wednesday, Moderna reported it saw a “significant increase in the rate of case identification across sites in the last week,” and because of this, the company expects its first analysis of its vaccine will “include substantially more than 53 cases, the targeted trigger point for the analysis.”

Data on these cases are being prepared for submission to the independent Data Safety Monitoring Board (DSMB) for analysis and recommendation.

However, researchers do not yet know yet if those who got sick were given the vaccine or a placebo. If enough received the vaccine, this will help to further learn how effective the vaccine is.

Additionally, if Moderna’s vaccine is approved and effective, it would be given in two doses, four weeks apart. The vaccine would be stored at negative four degrees Fahrenheit.

This varies from leading vaccine candidate, Pfizer, whose vaccine would be given in two doses three weeks apart, and stored at a much cooler temperature. Pfizer’s vaccine needs to be stored at -94 Fahrenheit, which presents a potential logistical issue in how it’s distributed.

If the vaccine is effective, Moderna could apply for emergency use in December.