Another promising vaccine, this one from Johnson & Johnson

To break Covid, the different vaccine candidates, which have their own advantages and disadvantages, must be optimally exploited and adapted to stay ahead of viral mutations. The vaccines all follow a similar basic approach, mastering the spike protein found on the surface of the coronavirus. But Johnson & Johnson’s vaccine takes a slightly different approach to delivery than vaccines produced by Pfizer and Moderna. (I am on the Pfizer board.) The biotech company Novavax is looking for a candidate vaccine with its own special delivery system. All four may be available by summer, which would mean a wide range.

Americans will wonder which one works best? It will be tempting to compare data between studies. But that’s not apples to apples; the vaccines and the data are not all the same. And new variants of Covid may require vaccines that provide slightly different layers of protection and target slightly different parts of the virus.

The regulatory process should encourage this kind of portfolio diversification, while allowing tweaks to stay ahead of the twists and turns of the virus. The FDA is working on guidelines to address new variants, including a route for updating vaccines.

The model should be the flu vaccine process. Every year, scientists develop the basic components for flu vaccines that can target many different strains of the virus. But only the three or four species expected to be the most common are put into production. The rest is left on the shelf, ready for production should the flu take an unexpected evolutionary turn. The FDA should do the same for Covid.

Second, it is essential to design clinical trials that can be completed within months to avoid possible outbreaks of new variants. It is fast, but given the current scientific possibilities that could be enough time to perform the required tests.

Take the South African variety known as B1351. Existing trials will be used to determine that current vaccines provide clinical protection against Covid’s disease. But to prove that the new versions targeting B1351 work just as well as current vaccines, the FDA can measure the plasma antibody levels of patients recovered from B1351 and set a benchmark for the number of antibodies needed to treat neutralize that virus. Then, the FDA can use those antibody levels as a proxy to evaluate whether updated vaccines can generate adequate levels of protection.

This could allow vaccine manufacturers to test new boosters in clinical trials enrolling 300 or 400 patients instead of 40,000, a huge cost and time savings. At the same time, larger and longer studies can be started, including those following vaccinated patients.

The virtue of the new vaccines is that they are obtained by synthetic processes using the sequence of the coronavirus RNA. This means that the vaccines are relatively easy to update when new variants emerge.

Another priority should be the development of antiviral drugs. We need more tools that focus on central features of how the viruses multiply and that do not rely on targeting proteins found on the surface of the virus. These drugs can remain effective even if the virus mutates.

The best backstop against the widespread transmission of mutant strains is still the same: an audience taking precautions like social aloofness and masks, combined with a thoughtful and nimble vaccine development system.

Dr. Gottlieb is a resident fellow at the American Enterprise Institute and was a Commissioner of the Food and Drug Administration, 2017-19. He is a board member of Pfizer and Illumina.