Moderna just made the Pfizer vaccine's biggest weakness an even bigger one

Since announcing the launch of their phase 3 vaccine trials on the same day in July, Pfizer and Moderna have been fierce competitors in the Covid-19 vaccine competition, however, Moderna has been edging past Pfizer in recent times.

Pfizer, took the lead on the way to the finish line in December as the major pharma corporation received the first FDA emergency use authorisation (EUA) for a coronavirus vaccine.

But, Moderna wasn't far behind; the vaccine from the smaller biotech firm received the EUA just seven days later. Since then, the two firms have essentially continued to compete in lockstep, reports The Motley Fool.

So far, 49 million Americans have received both doses of the Pfizer vaccine, which was developed under the code name BNT162b2 but is now known as Comirnaty, and 40 million have finished their Moderna vaccine, which is now known as mRNA-1273. 

Both companies are also developing booster shots and conducting clinical trials that will enable them to begin inoculating children and teenagers. However, Comirnaty has one major flaw. And mRNA-1273 may be able to take advantage of this flaw, as well as Moderna's recent news.

A key difference between the two mRNA vaccines

Pfizer and Moderna both developed mRNA vaccines for Covid-19. They use messenger RNA to induce the body to produce a key protein found on the surface of the coronavirus. Then, the immune system creates antibodies that recognize that protein, thus preparing the body to fight off the coronavirus. But their vaccines are not identical. One of the big differences from the start has been their storage temperature requirements. And that's where Pfizer's weakness lies.

For longer periods, Comirnaty must be stored at ultra-cold temperatures -- between minus 112 degrees Fahrenheit and minus 76 degrees Fahrenheit. The vaccine may be kept at standard refrigerator temperatures for five days.

As Pfizer has collected more data, it has been able to loosen some guidelines for shorter-term storage. For instance, the company earlier this year said its vaccine may be stored at relatively higher temperatures (minus 13 degrees Fahrenheit to 5 degrees Fahrenheit) for two weeks. These are temperatures that standard pharmaceutical freezers can maintain. The Food and Drug Administration approved those new storage guidelines.

So, pharmacies and healthcare facilities can easily store the Pfizer vaccine for 19 days. I'm counting the refrigerated temperature period and the pharmacy freezer temperature period.

Easier from the start

Moderna's mRNA-1273 has offered an easier storage profile from the start. Right now, the guidelines say it can be kept at standard refrigerator temperatures (35.6 degrees Fahrenheit to 46.4 degrees Fahrenheit) for as long as one month. It can be stored for as long as seven months in a standard freezer. But this week, Moderna said further research showed that mRNA-1273 can be safely maintained at refrigerator temperatures for up to three months. The FDA still must approve those new guidelines.

Moderna also is studying new formulations of its coronavirus vaccine that would further improve its storage profile.

The possibility that Moderna's Covid-19 vaccine could be stored for as long as three months in a standard refrigerator could give it an even bigger leg up in the marketplace. Pfizer ensures the safe transport of its vaccine with special thermal containers. But in smaller healthcare settings, the problem is on-site storage. Many doctors' offices or pharmacies may prefer to stock up on a vaccine that can be kept in a refrigerator for a long period of time. They may have limited freezer space -- or no freezer space at all.

And in some countries, temperature requirements could be decisive when it comes to which vaccine governments and healthcare providers choose. Nigeria, for instance, said earlier this year it would favor vaccines that require less cooling.

An evolving vaccination situation

When Covid-19 vaccines first began to roll out, countries were aiming simply to vaccinate as many people as possible, as rapidly as possible. So, they ordered what was available. But as various vaccine makers continue to ramp up production and refine their offerings, countries will have more choices -- and a bit more time to consider those options. This is when Moderna could take the lead.

Will this mean major market dominance for Moderna and a big loss of revenue for Pfizer? No. True, mRNA-1273 could move into the top spot due to its easier storage requirements. But if that happens, Pfizer's Comirnaty will remain close behind it. No single company can make enough doses to vaccinate the more than 7.8 billion people in the world with the necessary speed. Moderna and Pfizer each aim to produce 3 billion doses of their coronavirus vaccines next year, and each requires a person to get two doses. So even if a country prefers Moderna's vaccine, for example, it likely will still have to order some doses from another vaccine maker to cover all its citizens.

The Moderna vaccine's easier-to-manage temperature requirements won't upend Pfizer's prospects for billions in dollars of sales of Comirnaty. But this latest news is likely to lead to a boost in orders for mRNA-1273, and may significantly increase Moderna's product sales over the long term.