Let's face it: Some companies that are receiving a lot of hype right now about their COVID-19 programs won't have staying power. Small biotechs claiming to have a game-changing treatment on the way could run into the harsh realities of clinical testing. Diagnostic test makers with all of their chips on COVID-19 could be left in the dust a couple of years from now when the pandemic has run its course.

The stocks of such companies might be OK for traders to buy to make a quick buck in the short run. But they're unsuitable for investors seeking to generate big gains over the long run. Here are my picks for the three best coronavirus-related stocks to buy for long-term investors.

Image source: Getty Images.

Abbott Labs (NYSE:ABT) quickly rolled out several COVID-19 diagnostic tests after the coronavirus hit with full force earlier this year. Its ID NOW test, which received FDA Emergency Use Authorization (EUA) in late March, attracted significant attention because it offered the fastest results of any COVID-19 test available.

I expect that COVID-19 testing will continue to fuel sales growth for Abbott over the next few years. However, there are several more important growth drivers for the company.

Put Freestyle Libre at the top of the list. Abbott recently won FDA clearance for a new version of the continuous glucose monitoring (CGM) system that supports integration with other medical devices. My prediction is that Freestyle Libre 2 will enjoy skyrocketing consumer demand and be a resounding success for Abbott.

Wall Street analysts project that Abbott will be able to deliver average annual earnings growth of more than 10% over the next five years. I think that estimate is realistic. Throw in Abbott's reliable dividend, and you've got a blue chip stock with a COVID-19 focus that's likely to beat the total returns of the S&P 500 over the long run.

Gilead Sciences (NASDAQ:GILD) has been at the center of the coronavirus world since its antiviral drug remdesevir was first touted as a potential treatment for COVID-19. With late-stage clinical studies now supporting the safety and efficacy for remdesivir, Gilead is well positioned to remain a fixture in the fight against the novel coronavirus.

However, it's Gilead's treatment for another virus -- HIV -- that has been and will continue to be its biggest opportunity. The biotech's lineup includes multiple blockbuster HIV drugs. Gilead is evaluating a long-acting HIV therapy in phase 2 clinical studies that could be its greatest commercial success yet. Looking further down the road, the company could even have a cure for HIV on the way.

Thanks to its strategic partnership with Galapagos, Gilead is poised to make its mark in immunology. The company awaits U.S. and European regulatory approvals for filgotinib in treating rheumatoid arthritis. It also is likely to become an even bigger player in the oncology market with new indications for CAR-T therapy Yescarta potentially on the way and the acquisition earlier this year of cancer-focused biotech Forty Seven.

My view is that Gilead's COVID-19, HIV, immunology, and oncology programs will enable the big biotech to deliver solid growth over the long run. That growth will be bolstered by one of the most attractive dividends in the healthcare sector: Gilead's dividend yield currently stands at nearly 3.7%.

While lots of small biotechs have scrambled to develop COVID-19 therapies, I've kept my eyes onEli Lilly (NYSE:LLY). The big drugmaker has moved at breakneck speed with its partners to advance two COVID-19 antibody therapies into clinical studies. It's also evaluating blockbuster rheumatoid arthritis drug Olumiant and pipeline candidate LY3127804 in treating COVID-19.

I won't be surprised if Lilly achieves success with at least one of its coronavirus efforts. In the meantime, the company's diabetes drug franchise continues to rock along thanks primarily to strong sales for Jardiance and Trulicity. Lilly is also a top contender in the immunology market with Olumiant and Taltz.

The company's greatest growth opportunity, though, could be in oncology. Lilly recently announced overwhelmingly positive results from a late-stage study of Verzenio in treating early-stage breast cancer. It won FDA approval in May for Retevmo in treating lung and thyroid cancer. Cyramza also continues to pick up momentum in treating several solid tumors.

Analysts think that Lilly could deliver average annual earnings growth of nearly 13% over the next five years. That level seems quite attainable to me, considering the company's solid current lineup and promising pipeline. With Lilly's dividend yield of 1.8% included, I think the pharma stock should easily outperform the overall market's total returns over the long run.

Read more:
The 3 Best Coronavirus Stocks to Buy for Long-Term Investors - The Motley Fool