Moderna's coronavirus vaccine overcomes one of the biggest limitations of Pfizer's shot

• Moderna on Monday said that its coronavirus vaccine works to prevent COVID-19.
• Moderna is now the second drugmaker to share positive results for a coronavirus vaccine after Pfizer said a week ago that its shot works.
• Pfizer's vaccine needs to be stored at negative 94 degrees Fahrenheit, presenting a challenge for vaccine distribution.
• Moderna's vaccine, however, is stable for up to a month at standard refrigeration temperatures, between 36 degrees Fahrenheit and 46 degrees Fahrenheit.

Moderna on Monday said that its experimental vaccine was effective at preventing COVID-19, the disease caused by the novel coronavirus.

The findings come from a massive and well-designed study, but they haven't been reviewed by outside experts or by regulators. The news comes just one week after Pfizer shared that its vaccine was effective in preventing COVID-19, sending markets soaring on the hope that an effective vaccine would help end the pandemic.

Moderna's shot comes with one crucial advantage over Pfizer's: It doesn't require a deep-freeze. Instead, the shot can be stored at standard refrigerator temperatures for up to a month, Moderna said on Monday.

Hospitals and health officials were working to figure out how to store and distribute Pfizer's shot, particularly in more rural areas, because the process can involve dry ice and special freezers. Some hospitals and city and state health officials were seeking to acquire the special freezers to store that shot, Reuters reported.

Pfizer's shot is stored at extremely cold temperatures

Pfizer's vaccine needs to be shipped and stored at negative 94 degrees Fahrenheit, a temperature colder than what's needed for most other vaccines. That can be challenging in the US and presents even more of an obstacle in some other countries.

Pfizer will ship the vaccine by air and land using dry ice, along with reusable GPS temperature-monitoring devices.

Pfizer is working on a next-generation version of its shot that wouldn't need to kept at extremely cold temperatures, the company's chief scientific officer told Business Insider.

Read more: Pfizer's top scientist tells us the pharma giant is already thinking about a new version of its coronavirus vaccine for 2021 that can overcome one of its biggest limitations

Moderna's only requires standard refrigeration

Moderna's vaccine, meanwhile, can be stored using standard refrigeration for up to 30 days, the company said on Monday. That greatly simplifies the distribution challenge compared to Pfizer's shot.

The shot is stable for a month at anywhere from 36 degrees Fahrenheit to 46 degrees Fahrenheit, which is the standard temperatures of refrigerators.

Moderna's vaccine can also be stored for up to six months at -4 degrees Fahrenheit, a typical temperature requirement that hospitals and clinics are used to.