Biotechnology firm Moderna announced Monday, Nov. 16 that their vaccine reduced the risk of COVID-19 infection by 94.5%, making it the second vaccine in the United States to have such a high success rate.

Just a week prior, Pfizer and its German partner Biotech announced that their vaccine operates at over 90% effectiveness.

“I’d like to say I would have predicted it, but I would not have,” the nation’s top disease expert Dr. Anthony Fauci said. “Honestly, I would not have expected that. I thought that was too much to hope for.”

After the FDA gives its stamp of approval, Moderna and Pfizer will distribute their vaccines starting in December, but only to high risk groups — healthcare workers, the elderly and people with underlying conditions. Moderna and Pfizer project to respectively release 20 million vaccines that month, with more coming in 2021 as production increases.

Those who do not fall into the high-risk group may  have to wait until April to get vaccinated. Vaccine distribution requires extensive collaboration between the federal and state governments, pharmaceutical companies and healthcare providers.

Moderna and Pfizer yield similar results due to their use of mRNA technology, which has never been on the market before. The vaccines contain genetic material that prompts one’s body to create a protein around the exterior of the virus, effectively training one’s immune system to see the virus as a threat. 

Moderna’s vaccine, mRNA-1273, would be given in two doses, 28 days apart. The 30,000 patient study tested this: half received two doses of the vaccine and half took a placebo. Meanwhile, physicians carefully monitored symptomatic cases of COVID-19 to see if they occurred predominantly in the placebo group.

In the trial, 95 cases of COVID-19 developed, with 90 cases taking place in participants who took the placebo. The study had 11 severe cases, which all transpired in the placebo group.

According to Moderna’s news release, the vaccine yields minimal side effects, mostly mild or moderate, that includes symptoms like pain at the injection site, fatigue, headache and muscle pain.

As of now, Moderna seems to have the advantage when it comes to accessibility, since the Pfizer vaccine requires minus 70 degrees Celcius storing conditions. Moderna’s vaccine can be stored at refrigerator temperatures for a month and frozen for six months. It also does not require dilution at the point of care, unlike the Pfizer vaccine.