As yet another new Sars-CoV-2 variant emerges and begins to spread — one with a worryingly large set of mutations that may make the virus more capable of evading our immune defences — we are all being forced to reassess the strategies we have come to rely on for protection.
In many countries, like the United States, vaccines have been viewed as the primary ring of protection, allowing Americans to live in relative security from the virus. But the more we learn about the virus’s ability to dodge and elude the early lines of immune-system defence, the more obvious the need for additional measures becomes. Instead of relying on a single layer of protection, we should adopt a “belt-and-suspenders” approach. Vaccines remain the primary ring of support — the belt keeping our protective pants on straight. But we would do well to add a set of suspenders for additional support, just in case the belt breaks under mounting pressure from the virus. Based on what we know, our best bet lies with the wider use of monoclonal antibodies for early treatment of Covid-19 and for long-term prevention and protection from the disease.
To see the importance of this approach, imagine a long-term care home in which one resident tests positive for Covid-19, or a ship or submarine at sea, where there would be no possibility of relief from continual and intense exposure in the event of an outbreak. If the people in these congregate settings were immediately administered a single dose of monoclonal antibody treatment, the odds of an infection in that group leading to severe disease would be reduced by up to 70 per cent. And beyond protection from disease, the single dose would also have a powerful preventive effect for future infection, providing ongoing protection for up to eight months.
As is the case for most antiviral drugs, monoclonal antibodies will need to be tailored to counter the particular strains circulating at any given moment. But the benefit remains: a single dose could protect people for up to eight months with no additional pills and no additional doses required. Consider what this intervention could mean for all the people in congregate living settings or at higher risk of severe disease. If you are older, morbidly obese, immunocompromised, or unable to mount an immune response after vaccination, new data show that you are much more likely than your healthier, vaccinated counterparts to have not only a breakthrough infection but also a more severe illness. This single injection could still save you.
Moreover, we already have a very good understanding of the potential adverse effects of monoclonal antibody treatments. All are manageable, which is more than can be said of the antiviral pill molnupiravir, which is currently before the FDA for emergency-use approval. Its potential side effects, heatedly discussed among the FDA experts who issued a very narrow approval, include potential birth defects and the possible mutagenesis of the virus itself, essentially supercharging the virus’s ability to create highly mutated variants. The side effects of other pills awaiting further study are still unknown.
The challenge with applying the belt-and-suspenders approach in the past has been the cost of production and the burden of delivery of first-generation monoclonal antibodies. Initially, the therapies could be administered only intravenously, in a clinical setting, over a period of hours. To be effective, the dose needed to be delivered shortly after symptoms appeared and before severe illness set in. Between the high costs and the extra administrative demand placed on overburdened health-care systems, this treatment option simply could not have been applied broadly as a preventive tool. @Project Syndicate 2021
The author is a scientist, biotech entrepreneur, and infectious disease expert, is Chair and President of the global health think-tank ACCESS Health International
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