The Washington PostDemocracy Dies in Darkness

Opinion It’s a pandemic miracle: I’m defending the FDA against Ron DeSantis

A monoclonal antibody treatment center in Florida is closed on Jan. 25 after federal health regulators found the treatment ineffective against treating the covid-19 omicron variant. (Marta Lavandier/AP)
Placeholder while article actions load

Florida Gov. Ron DeSantis (R) truly is some kind of miracle worker. He is about to make me defend the Food and Drug Administration’s decision to keep a drug off the market.

On Monday, the FDA withdrew emergency use authorization for two monoclonal antibodies that don’t work well against omicron, the dominant coronavirus variant in the United States. Florida, which has made monoclonal antibody access central to its pandemic policy, announced that it was shutting down its infusion centers. DeSantis threatened to sue the FDA.

Alt-right blogger Mike Cernovich went further, tweeting “The FDA is trying to make it so that people in Florida die of Covid. They’ll kill people to harm Republicans.” This was retweeted more than 3,200 times, including by Christina Pushaw, DeSantis’s press secretary.

I am trying to find a less perjorative word than “crazy” to describe this situation. Don’t get me wrong: As a longtime critic of the FDA’s excessive caution, I get why conservatives might want a “right to try.” Moreover I understand why conservatives assume that the agency has been politicized; the decision to delay announcing the results of vaccine trials until after the 2020 election gave off political overtones, even if you think that’s a false impression.

Yet precisely because I’ve spent years of watching the FDA with a gimlet eye, I’m quite sure that this is not an attack on Republicans; it’s just the FDA doing what it always does. Moreover, in this case, it’s probably doing the right thing.

Follow Megan McArdle's opinionsFollow

To understand why, you have to understand how monoclonal antibodies or mAbs, work, and why experts believe these ones don’t. This helps explain the FDA’s (also correct) decision to leave vaccines on the market even though they also show reduced efficacy against omicron.

It all comes down to the antibodies. You can think of a virus as using a kind of key (such as the infamous spike protein) which unlocks our cells so the virus can get inside. Some antibodies glom onto part of that key, so that it no longer unlocks the door — as if you’d stuck a bit of clay onto the notches of your house key. Meanwhile, another part of the antibody “signals to the immune system: ‘Hey, I’ve got a live one’,” says drug researcher Derek Lowe, who was kind enough to walk me through the chemistry.

Kathleen Parker: Is it time for Fauci to exit the stage?

Your body responds to the virus by trying lots of different antibodies that react to different parts of the pathogen, with varying degrees of effectiveness. Manufactured monoclonal antibodies are more focused: Researchers find the ones with the highest activity and produce a whole bunch of just a few of them. The benefit of mAbs is that unlike vaccines, which do not help against an active infection, they can treat patients already infected with covid-19..

“The thing with monoclonal antibodies is that you get exactly what you want and nothing but,” says Lowe. “But if anything changes, they’re useless.” That is, if the virus mutates, a monoclonal antibody might be the wrong shape to lock onto the new variant, while the broader natural response might still generate at least a few that work, as well as other kinds of immune responses.

This helps explain what we’ve seen with omicron. Because this variant has so many mutations, people who have been vaccinated, or survived an earlier covid infection, have defenses that don’t prevent infection as well as they used to. But we might still have some antibodies that are effective, and a battery of other immune defenses that also kick in, so the infections still tend to be milder. Many monoclonal antibodies, by contrast, have lost some or all of their effectiveness — so much, in the two that were just withdrawn, as to render them basically ineffective.

But why not leave them on the market for people who have other variants? Well, omicron is now estimated to account for 99.9 percent of new cases. With those case rates, we’d need to pump a thousand doses into covid patients’ arms — at thousands of dollars a pop — in order to potentially help maybe one. And even that one wouldn’t necessarily benefit. Most people recover from covid without monoclonal antibodies, and some people don’t even if they get them.

All treatments have side effects, including allergic reactions. So the FDA tends to balk if you have to treat a large number of patients, most of whom might recover without treatment, to potentially help one. And that was true long before covid-19.

None of this was remotely controversial before the DeSantis administration attacked the FDA. It was widely agreed that many previously effective monoclonals were now of little use against omicron. In the case of the withdrawn treatments, even the manufacturers, Eli Lilly and Regeneron, agree they don’t work. No sane governor should want to waste money and scarce medical resources on pumping useless antibodies into Floridian veins.

Of course, DeSantis is not insane; he is a shrewd political operator who is eyeing a presidential run in 2024. He has clearly decided that one way he can outflank former president Donald Trump with the Republican base is to appeal to vaccine skeptics, many of whom embraced antibodies enthusiastically. That might be one reason DeSantis made these drugs a centerpiece of Florida’s pandemic strategy — and why he is now manufacturing a controversy out of a completely unremarkable, and eminently defensible, decision by the FDA.