Coronavirus antibodies have potential as both treatments for COVID-19 and as a prophylactic to prevent people exposed to the virus from developing the disease. Unfortunately, the antibodies aren't particularly easy for doctors to use. In this video from Motley Fool Live, recorded on Feb. 1, contributors Brian Orelli and Keith Speights discuss the limitations of the antibodies.

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Brian Orelli: Then story No. 4. New data on the antibody treatments. One from Eli Lilly (LLY 0.87%)that's a cocktail of two antibodies. They had previously, I think, had data for a single antibody. With two antibodies, they reduce the risk of hospitalizations or deaths by 70% compared to placebo. There were 10 deaths in the placebo group and none in the group that got the cocktail. All the reduction was with -- all the people who had an event in the cocktail group or hospitalizations. There's a lot of issues with this treatment. It needs to be given early to be effective. But they want to save it for only the people who are most likely to get really sick. It's hard to tell really early whether somebody is going to get really sick. Then it requires a really high dose, which has limited the manufacturing capacity to make the number of doses.

They're studying a lower dose which at least in pharmacokinetic data, which is basically just looking at the amount of antibody in the bloodstream. They seem to be able to get sufficient levels with a lower dose, and now they're testing a lower dose for efficacy. It also takes a 60-minute infusing time. You're talking about people with COVID-19 that have to be infused normally. You think of pictures of cancer wards where people are getting infused and there's a whole bunch on chairs sitting around, nobody is talking to the people that they've come with. Obviously none of that's happening. Everybody is going to be gowned up and separated. That's really difficult to have a 60-minute infusion of somebody who's already tested positive for COVID-19. The company is looking to cut that down to 16 minutes, which might help a little bit, but it's still a big issue for getting everybody gowned up and the worry of the people that are administering the drug.

Keith Speights: Those are some real limitations for Eli Lilly's antibody therapy here. That long period of infusion. As you said, it has to be given so early, and they're limiting it to the high-risk patients. I think remains to be seeing what the real impact of Lilly's antibody therapy will be. It is a cocktail. One of those therapies is already on the market under Emergency Use Authorization. The other one isn't. The cocktail is promising, but I think it's going to be important for Lilly to get that infusion time down.

Orelli: They're also testing a cocktail with one of their antibodies with Vir Biotechnology's (VIR 1.98%) antibody. Vir working with GlaxoSmithKline (GSK -0.55%), but Vir is the one that discovered the antibody. The Vir's antibody binds to an area that's identical between the original coronavirus that cause SARS and the coronavirus that causes COVID-19. The fact that they're identical means that probably if you get a mutation in there, that lowers the efficacy of the virus or makes it so it can't infect the cells at all. Hopefully that means that antibody binding to that area would be active against any variant that might show up because any variants in that region might not be active.

Speights: Brian, don't you think we're at that stage where we'll see more of this type of thing where one company's therapy, they conduct studies in combination with another company's therapy. I think we're at that point in the life span of some of these development efforts that we'll see more of this going forward.

Orelli: I think we've even seen some companies teaming up on manufacturing. I think that solving the problem as a group is definitely the way to go. I think companies are more willing to do that, especially companies that are late in development and don't have any other options to get it in on the take.

Then Regeneron Pharmaceuticals (REGN -0.27%) also has a COVID-19 antibody or coronavirus antibody cocktail -- two antibodies. They had data last week as a prophylaxis to prevent people from getting COVID-19 -- who have been exposed because somebody else in their household had it. They had 100% prevention of symptomatic infections. There were eight in the placebo group at 223 and none in the group got the cocktail out of 186. That was symptomatic infections. There were some asymptomatic infections for the people who got the antibody, but there was a decrease in the amount of virus that they were setting and how long they should have the virus for. It seems to be working fairly well as a prophylaxis, and I could see this as a better option than treatments, although it's sort of becomes useless once we have enough vaccine to cover everybody.

Speights: I think Regeneron was even referring to this as passive vaccination. It's not a vaccine, but if you take it after being exposed, it can work. Not work in a similar way, but it has some of the same effects as a vaccine because it does prevent infection. I think the great thing about Regeneron's antibody cocktail is that it doesn't require infusion. This is just an injection, subcutaneous injections. I think that's a big plus and probably will open up more market potential. But as you said there, Brian, I think the number of COVID vaccines increase and become more widely available, it could diminish the need for some of these other therapies and prophylaxis like this.