It's fair to say Pfizer (PFE) has become a coronavirus vaccine powerhouse. The big pharma company landed the first Emergency Use Authorization (EUA) for a COVID-19 vaccine in December. And it has managed to stay ahead of rivals so far. It's fully vaccinated more than 35 million people in the U.S. That's compared to 30 million for Moderna and 6 million for Johnson & Johnson.

Pfizer and partner BioNTech expect the vaccine to generate about $15 billion in revenue this year. Now, they're going after a broader audience that could boost sales further in the years to come. Pfizer just requested an EUA for use of its vaccine in individuals ages 12 through 15. That's after reporting positive trial data. The current authorization covers people ages 16 and older. All of this sounds great. But, if the U.S. Food and Drug Administration (FDA) gives Pfizer the nod, there's one big challenge the company faces.

A mom hugs her teenage daughter in their living room.

Image source: Getty Images.

The most vulnerable

Older people have been among the most vulnerable to the coronavirus since the start of the pandemic. The number of cases in younger people has increased. But deaths still remain extremely low in younger groups. For example, 0.1% of deaths have been in Americans ages 5 through 17, according to the Centers for Disease Control and Prevention (CDC). More than 31% of deaths have been in people ages 85 and older.

And in many instances, kids and teens who have contracted COVID-19 have been asymptomatic or have had mild cases. So, the big challenge Pfizer faces is actually getting parents to sign their kids up for a vaccine. My colleagues Keith Speights and Brian Orelli had an interesting conversation about this on Motley Fool Live recently.

Parents may eagerly opt for vaccination if their teens are in a high-risk group. Otherwise, some may just skip it. What could change this and potentially increase teen vaccination rates? Communication from vaccine makers, the government, and healthcare providers. If health officials explain the importance of vaccinating all age groups, that could tip the balance in favor of vaccination.

Two reasons to vaccinate

There are two important reasons to vaccinate this group. First, kids and teens are key to reaching herd immunity. Experts say about 50% to 80% of the population must be immune to the virus to reach that stage. People under age 18 make up 22% of the U.S. population. And second, vaccination helps reduce transmission of the virus. If fewer people are sick -- asymptomatic or symptomatic -- fewer viral particles are shed into the community. And that lowers the risk for more vulnerable people.

Ideally, if parents support vaccination, this could be a big revenue opportunity for Pfizer. More than 25 million individuals in the U.S. are between the ages of 12 and 17, according to Kids Count data. That means 50 million doses are needed for this group. Using the $19.50 a dose price the U.S. paid for Pfizer vaccines, this represents $975 million in sales for the company. It's logical to imagine global sales could reach into the billions -- just for this age group.

And Pfizer is likely to enter this market first. Moderna also is testing its vaccine in this age group, but it hasn't yet reported data. If Pfizer lands an EUA even a few weeks ahead of Moderna, it could gain significant market share. Parents who do want vaccinations for their kids will scramble to get it done before the back-to-school period.

A lot of good news

There's a lot of good news here for Pfizer, including a potentially billion-dollar global market and the ability to reach this market ahead of rivals. But the possibility of low interest from parents could put a serious dent in revenue prospects.

Now the question is: Should this be a big worry for investors? And the answer is no. As I mentioned earlier, the coronavirus vaccine already is generating blockbuster-level sales for Pfizer. And that won't change even if teen vaccination rates are low.

I see the teen market as a plus -- but right now it's not a "make-it-or-break-it" opportunity. It may take a while to win parents over. And that's OK. Meanwhile, as long as Pfizer's overall coronavirus vaccine revenue and orders continue to grow, there's reason to be optimistic about the company's role in this dynamic market.