Amid breaking reports Monday morning that Moderna’s coronavirus vaccine candidate reached 94.5% efficacy rate, according to a company announcement, many are comparing the vaccine to Pfizer’s candidate — announced just last Monday as having 90% effectiveness.

Some experts, including Dr. Anthony Fauci, have embraced the idea of multiple coronavirus vaccines in order to meet global demand--if the vaccines are approved, that is--and to help put an end to the ongoing health crisis that has resulted in at least 54.5 million infections globally and over 1.3 million deaths worldwide, says data from Johns Hopkins University.

Both Moderna and Pfizer's vaccine candidates involve two doses of the injection to the arm. (iStock)

Both Moderna and Pfizer's vaccine candidates involve two doses of the injection to the arm. (iStock)

At the moment, both Pfizer and Moderna are gathering the two months' worth of safety data needed for emergency approval from the Food and Drug Administration, aside from additional assessment by other independent advisory groups, like VRBPAC. Pfizer previously said it expects this safety data in the third week of November, while Moderna expects to file for FDA approval in a few weeks. Nevertheless, both vaccine candidates involve two doses of the injection to the arm several weeks apart--21 days apart for Pfizer, 28 days for Moderna.

“It’s like a typical vaccine, you clean your arm with a bit of product to make sure you don’t get contaminated, you inject the vaccine and you put a Band-Aid and that’s it,” Stephane Bancel, Moderna CEO, told Fox Business’ Maria Bartiromo in an interview Monday. Bancel compared the vaccine to a flu shot.


After Pfizer surfaced with positive early findings on its coronavirus vaccine candidate last week, experts were hopeful another effective vaccine would follow given similar gene technology, or the so-called messenger RNA (mRNA) platform. The new technology, which is being used by Pfizer and Moderna, injects the genes for these "spike proteins" into healthy cells to induce an immune response.

So while the two vaccines share similar technology, they do differ in terms of “user friendliness,” in terms of temperatures needed for storage. 

Bancel told Fox Business that the company newly learned its vaccine candidate has six months of shelf life in a regular freezer, at minus 20 degrees Celsius, and up to 30 days in a refrigerator.

“Those freezers are widely available at pharmaceutical distribution centers because there are FDA-approved products [that] require minus 20 [degrees Celsius for] storage, so that’s not a problem,” Bancel said.

“For a month, you can take the product out of the freezer, and then you put it in a regular fridge, like you store insulin,” Bancel added, suggesting major gains for usability.


Meanwhile, Pfizer’s vaccine must be stored at temperatures of minus 70 degrees Celsius or below. In countries with intense heat and in regions with spotty electricity, these requirements will prove problematic.

“The logistics of distributing the Pfizer vaccine, if proven to be safe and effective, will no doubt be a Herculean task,” Andrew Peterson, assistant professor of philosophy at George Mason University, previously told Fox News. “Beyond the challenge of physically transporting the vaccine by air and land to distribution centers across America and internationally, there are the additional obstacles of keeping the vaccine at sub-zero temperatures and monitoring deliveries for theft.”

In an emailed statement to Fox News, a Pfizer spokesperson addressed the vaccine's cold temperature storage requirements.

"Our track record gives us confidence in our ability to quickly scale and manufacture and distribute large quantities of a high-quality COVID-19 vaccine, leveraging multiple sites in the U.S. and Europe," per the emailed statement. "We have developed detailed logistical plans and tools to support effective vaccine transport, storage and continuous temperature monitoring. Our distribution is built on a flexible just-in-time system which will ship the frozen vials to the point of vaccination."

Bancel said Moderna expects to have 20 million doses ready by the end of the year, and Alex Azar, secretary of the Department of Health and Human Services (HHS), recently told reporters that distribution for Pfizer's vaccine will potentially begin in late November in increments of about 20 million doses per month.


Fox News’ Alexandria Hein contributed to this report.