Moderna (NASDAQ:MRNA), the first company to launch a coronavirus vaccine trial in humans, has been the subject of lots of buzz over the past several months. And when people weren't talking about Moderna's progress, they've been talking about its rivals in the race to bring a vaccine to market -- until recently.

After his COVID-19 diagnosis, President Donald Trump took, among other treatments, Regeneron's (NASDAQ:REGN) investigational antibody cocktail. He praised the product and said he would help deliver it to Americans as soon as possible. Soon afterward, the government offered another antibody-cocktail maker -- AstraZeneca (NASDAQ:AZN) -- $486 million to support its program.

Now the question is: Can these investigational antibodies for COVID-19 treatment and prevention push vaccine makers out of the limelight? Let's take a closer look.

A fist surrounded by images of coronaviruses pushes against a researcher's gloved fist.

Image source: Getty Images.

First of all, what's the difference between preventing disease with a vaccine and prevention using antibodies? Vaccines help the body make antibodies to fight infection. With antibody treatments, the actual antibodies needed to combat infection are administered through injection or infusion.

Here's where some of the players in this antibody treatment race stand.

Regeneron

Regeneron is the frontrunner so far. Earlier this month, the biotech company applied to the U.S. Food and Drug Administration (FDA) for an emergency use authorization (EUA) of its investigational antibody cocktail to prevent and treat COVID-19. The cocktail is a combination of two antibodies. The company selected them after screening antibodies from recovered coronavirus patients and from mice genetically modified to have human immune systems.

If the FDA grants an authorization, the U.S. government has agreed to make the product available to Americans free of charge and handle distribution. Regeneron said it has enough doses for 50,000 recipients now, and 250,000 more within a few months.

The cocktail is involved in an ongoing phase 1/2/3 trial. So far, Regeneron has included 2,000 participants in the program. Most recently, interim results showed the treatment reduced viral load and symptoms in non-hospitalized COVID-19 patients. Regeneron also is evaluating the cocktail in hospitalized patients, and as a preventative measure for those who had close contact with someone infected with the novel coronavirus.

AstraZeneca

Big pharma company AstraZeneca is moving its antibody candidate into two phase 3 trials this month. The trials, which will study the investigational product as a prevention method, aim to include more than 6,000 participants. The company plans additional trials in about 4,000 patients for the treatment of COVID-19.

As part of the U.S. government's investment in AstraZeneca's program as mentioned above, the company may provide as many as 100,000 doses, starting around the end of this year.

Eli Lilly

Eli Lilly (NYSE:LLY) is studying its antibody candidate, LY-CoV555, in both non-hospitalized and hospitalized coronavirus patients, and as prevention for residents and staff at long-term care facilities. Tests include the antibody alone, as well as LY-CoV555 paired with other antibodies or treatments.

Earlier this month, the pharmaceutical company submitted LY-CoV555 for an EUA as a monotherapy for high-risk patients recently diagnosed with mild to moderate COVID-19. More recently, however, this candidate reached a roadblock concerning another patient group.

The trial sponsor, the National Institute of Allergy and Infectious Diseases, paused enrollment in the study of LY-CoV555 in hospitalized patients. Details regarding the halt weren't available. The good news is that other studies of this antibody for SARS-CoV-2 may continue. But it's possible that this roadblock will slow the program's progress.

Stealing the spotlight

These and other investigational antibody treatments are attracting investor and media attention right now. In the short term, they may steal the spotlight from Moderna and other vaccine makers. But can they actually replace the need for a vaccine? That's unlikely.

Reasons include the high dosages required to treat coronavirus, and production capacity issues. The higher dose of Regeneron's cocktail is 8 grams, while blockbuster cancer treatment Herceptin is dosed at only 0.5 grams for a 150-pound patient.

As for production, Lilly says it would require about 300,000 square feet of manufacturing space, 50 processing vessels, and various other specific elements. Producing one batch of product can take 90 days.

Finally, cost is another problem. The price of antibody treatments means they aren't likely to be an affordable option for most governments. The average annual price of monoclonal antibody therapies is $96,731, according to a study published in The American Journal of Managed Care.

Which wins: Vaccines or antibodies?

A vaccine -- once approved -- may be the most practical option for widespread prevention, so it's clear antibody candidates won't knock out Moderna and other vaccine players.

But that doesn't mean antibodies are out of the picture. They hold the advantage of addressing not one, but two markets: prevention and treatment. They also represent an alternative for people who can't receive a vaccine for medical reasons. Even if antibody treatments aren't used in widespread national campaigns, if approved, they still will play an important role in the fight against COVID-19.

Investing in any of these companies could be worthwhile. But as always, invest because you're optimistic about a pharmaceutical company's overall portfolio -- never for just one program.