The pandemic has upended the healthcare industry, whether it's from the need to quickly but safely deliver new treatments to how patients can interact with their doctors to receive care.

Moderna (NASDAQ:MRNA) has been on the forefront of the creation of a COVID-19 vaccine, though doubts about whether there's more to the business after the pandemic subsides has begun to creep into the conversation. Similarly, Teladoc Health (NYSE:TDOC) benefited from the need for social distancing, but with the worst of the lockdowns a mere memory, worries about whether it can keep growing have held sway with many.  

Below, two Motley Fool contributors argue that both of these healthcare stocks have a very bright future indeed. Which is the better buy? 

Patient receiving an injection

Image source: Getty Images.

The case for Moderna

Adria Cimino: Moderna shares surged more than 400% last year. And they continued climbing this year as the company's coronavirus vaccine brought in billions of dollars in sales and profit. But a recent disappointment put a dent in the company's growing valuation.

Moderna lowered its vaccine-sales forecast for this year because it's prioritizing delivery to lower-income countries, which already pay less for doses than higher-income countries. So the news doesn't mean demand for Moderna's vaccine is falling, though investors still sanctioned the stock. It tumbled 32% in two days. Today, the vaccine stock is trading at less than nine times forward earnings estimates, down from a peak of 16 a few months ago.

Lab technician working with a specimen.

Image source: Getty Images.

The two-day loss wasn't an isolated event. Moderna shares already had started to lose steam in recent weeks as investors worry about whether coronavirus-vaccine sales will decline post pandemic.

But Moderna likely has a lasting opportunity in the coronavirus market, as experts say the virus will stick around. So the company could continue to benefit from the sales of its booster shot for quite some time. It also is developing a combined flu/coronavirus/allergy candidate.

But here's what's most important: Moderna probably won't have to uniquely rely on the coronavirus market for very long. That's because the company has a full pipeline -- and a close-to-market candidate with blockbuster potential.

Moderna recently launched the phase 3 trial of its cytomegalovirus (CMV) vaccine candidate. CMV is a common virus that represents danger for unborn babies and individuals with weakened immune systems. Right now, a vaccine for CMV doesn't exist, so if the pivotal trial is successful, Moderna could reach commercialization first or be among the first.

That equals an opportunity to carve out enormous market share. The company predicts peak annual CMV-vaccine sales of as much as $5 billion.

Considering coronavirus and booster sales of today and Moderna's promising future in mRNA therapies, any declines in the stock make a great opportunity to get in on this long-term story.

Doctor holding tablet computer

Image source: Getty Images.

The case for Teladoc Health

Rich Duprey: Virtual-healthcare specialist Teladoc is confounding Wall Street, which expected the number of virtual doctor visits to fall off dramatically as the number of people vaccinated against COVID grew. Because a reopened economy would encourage people to venture forth from their homes again and become more comfortable in settings where they're in proximity to others, the willingness to use telemedicine at the same rate would decline. It makes sense in theory, but that's not how it's playing out.

In Teledoc's third-quarter earnings report last month, year-to-date global virtual visits hit 10.5 million, or 20% more than what was achieved for all of 2020. U.S. virtual visits are running 45% ahead of the year-ago figure at the same time. Over the first three quarters of this year, total revenue has more than doubled.

The convenience of virtual-doctor visits that was discovered during the pandemic still resonates with patients now that they're on the other side of the crisis. Moreover, it's a situation where everyone benefits: patient, doctor, and insurers.

Telehealth services proved that being able to schedule convenient appointments, avoiding overbooked waiting rooms, and staying comfortable at home was an experiment worth repeating. Doctors were also given easier and earlier access to patients, particularly chronically ill patients who need more-intensive oversight, which should improve their health outcomes. That, in turn, should ultimately reduce out-of-pocket costs for health insurers.

In its recent presentation, Teladoc forecast revenue in 2022 would rise to $2.6 billion, ahead of analyst forecasts of $2 billion, with compounded annual growth of 25% to 30% through 2024, when revenue would hit $4 billion.

Stethoscope on smartphone and laptop.

Image source: Getty Images.

Yet that's only a portion of what Teladoc has going for it. Last year, it acquired Livongo Health, which uses artificial intelligence (AI) to send its chronic-care subscribers tips to help them lead healthier lives. At the end of the third quarter, it had 725,000 total unique members enrolled in one of its programs, up 31% year over year.

As Livongo expands beyond just diabetics to those with other conditions such as hypertension and weight management, its addressable market will expand exponentially, as well. In short, the healthcare stock has multiple avenues with which to transform patient care and reward investors who buy in as Teladoc's stock has tumbled 65% from its recent highs.

Both of these stocks still have long runways for growth. Developing new blockbuster therapies can generate substantial financial rewards for the companies and their investors, while changing how the interaction between patients and doctors occurs is a slower but steadier path to wealth.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.