When we think of halting the coronavirus pandemic, we think of vaccination. And when we think of who to vaccinate, we think of adults. Older adults, in particular, have been most vulnerable to the coronavirus. The U.S. Food and Drug Administration has authorized three vaccines -- those from Pfizer (PFE -1.94%), Moderna (MRNA -9.07%), and Johnson & Johnson. And the U.S. has fully vaccinated 21% of the adult population so far.

This is great. But it's important to vaccinate another part of the population to reach herd immunity. I'm referring to children and teens. Pfizer and Moderna are testing their vaccines in both groups. But Pfizer this week took a step that might push it ahead of Moderna.

A group of teens smile at into the camera as one takes a selfie.

Image source: Getty Images.

Teen trial data

Pfizer announced data from its trial in individuals ages 12 through 15 on March 31. Pfizer's vaccine is already authorized for use in people age 16 and older. In the new trial, Pfizer said its vaccine was 100% effective. And it produced neutralizing antibody responses that were even stronger than those in adult trial participants ages 16 to 25. Neutralizing antibodies are important because they block infection.

We should keep in mind that the trial was small: 2,260 teens compared with 43,448 adults in the trial that lead to authorization. And the company generated data after only 18 coronavirus cases accrued (all in the placebo group). In the adult trial, Pfizer analyzed data after reaching 170 coronavirus cases. So, it's possible that, in the real world, the vaccine won't be 100% efficacious in teens over time. Still, the data are encouraging and make me optimistic about the company's chances of winning Emergency Use Authorization (EUA).

Pfizer plans to submit the report to the FDA as a possible amendment to the EUA it already received. The company said it will do that "in the coming weeks." The goal is to vaccinate teens before the school year begins in September.

So where does Moderna stand? Moderna has said it expects to report data from its teen trial this spring. Like Pfizer, the company hopes to vaccinate this population before the back-to-school period. Moderna said recently that it has completed enrollment. Its trial includes 3,000 participants. Again, like Pfizer, it's conducting a small trial in this age group.

Ahead of Moderna

Pfizer's data report sets it ahead of Moderna from a timeline perspective. How far? That will depend on when Moderna reports results. Most kids in the U.S. return to school between Aug. 12 and Sept. 1. Pfizer observed high levels of neutralizing antibodies one month after the second vaccine dose. And doses generally are given about three weeks apart. Of course, the Pfizer and Moderna vaccines in adults have shown efficacy even after the first dose. But, ideally, kids should be fully vaccinated before returning to school.

This puts health systems on a tight schedule to get kids vaccinated on time. And that means the first company to market will have an edge. Even a couple of weeks could make a difference. And right now, it looks like Pfizer may be the one.

As for revenue, the opportunity is significant. In the U.S., more than 25 million individuals are between the ages of 12 and 17, according to Kids Count data. That's about 8% of the U.S. population. We can make a revenue estimate using the price paid by the U.S. for the Pfizer vaccine. That's $19.50 per dose. At two doses per person, our total revenue figure for the teen market is about $975 million.

Still, we should put all of this into perspective. Pfizer's latest data report is great news for the big pharma company. But Moderna investors shouldn't worry.

Even if Moderna enters the market after Pfizer, it still will claim some market share. We don't yet know if coronavirus vaccines will be needed for a few years or well into the future. But considering the depth of the pandemic, it's likely countries will want to continue vaccinations into the coming years. That means Pfizer and Moderna both could benefit well after the latest back-to-school period.