Key Points

  • In an interim analysis of Moderna’s phase 3 trial, all 11 cases of severe COVID-19 occurred in the placebo group.
  • Moderna will soon complete a final analysis of the phase 3 trial, to be used as a basis for Emergency Use Authorization.
  • Pfizer reported one case of severe COVID-19 in a trial participant who had received the company’s investigational vaccine.

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Moderna's (MRNA 0.66%) CEO Stephane Bancel calls his company's vaccine candidate a "game changer." But he's not talking about the mRNA technology that powers the vaccine. Instead, he's referring to one particular measure of performance in the vaccine's late-stage clinical trial: the ability of the vaccine to prevent severe disease.

Could this element make Moderna's vaccine the market leader? Well, it depends on final results from ongoing analyses of Moderna's late-stage trial. And it also depends on results from other vaccine makers. Let's have a closer look at what we know right now.

A masked researcher holds up a vial labeled "Coronavirus"

Image source: Getty Images.

Preventing severe disease

In an interview on Fox Business, Bancel said what he was most excited about was the Moderna vaccine candidate's ability to prevent severe cases of COVID-19. Moderna's trial enrolled more than 30,000 participants, each given either a vaccine or a placebo. Initial analysis involved 95 cases of COVID-19. Five occurred in the vaccinated group, and 90 occurred in the placebo group. Importantly, all 11 severe cases of COVID-19 happened in participants given placebo.

Rival Pfizer (PFE 1.19%) and biotech partner BioNTech (BNTX 2.14%) reported one severe case of COVID-19 in their vaccinated group. Nine other severe cases occurred in the placebo group. So far, Moderna is ahead in the area of severe disease prevention.

But here is an important point: Pfizer's efficacy analysis was a final one and included more coronavirus cases: 170. (Of those, 162 were in the placebo group, and eight were in the vaccinated group.) Moderna's analysis wasn't final. The company's final analysis, to be used as a basis for an Emergency Use Authorization (EUA) application, will include 151 COVID-19 cases. To confirm the vaccine's ability to prevent severe disease, this next data set will be key.

It also could be the key to pushing Moderna a step ahead of Pfizer from a data quality standpoint. From a timeline perspective, Pfizer moved into the lead last week when it submitted an EUA request to the U.S. Food and Drug Administration (FDA).

And Moderna may not be the only vaccine developer to excel at preventing severe illness. AstraZeneca (AZN 0.83%) just reported positive interim data from its phase 3 investigational coronavirus vaccine trial on Monday morning. The big pharma company said severe coronavirus cases didn't occur in any participants treated with its vaccine candidate. Does that put AstraZeneca and Moderna on par? Well, analysis so far puts Moderna in the top spot. The biotech company reported 94.5% efficacy for its candidate. AstraZeneca reported 90% efficacy for its best-performing dosage scheme. Another dosage level showed lower efficacy.

The final analysis

As with the comparison to Pfizer above, the one thing to consider is we haven't yet seen Moderna's final analysis. The numbers could change to some degree at that point -- for better or worse. But from what we've seen so far, there's more reason to be optimistic than pessimistic.

So, is Moderna's CEO right? Will this vaccine change the game? If final analysis confirms prevention of severe disease, Moderna will have nailed a key element for a successful COVID-19 vaccine. What people fear most, after all, is a severe case of COVID-19. If Moderna's vaccine outperforms others in this area, the company may take a good chunk of the market. However, if final analysis shows equal performance among the Moderna, AstraZeneca, and Pfizer vaccine candidates, other factors will determine which company will become a top supplier. For instance, AstraZeneca already has one particular advantage: Its vaccine candidate can be stored at much warmer temperatures than Moderna's and Pfizer's. The company has also pledged to sell its vaccine without taking a profit during the pandemic.

What does all of this mean for investors eager to bet on one of these companies? Even if one of the three takes market leadership, the others are likely to enjoy a good share. Worldwide need means business for more than one vaccine developer, as long as each company's data pleases the FDA.