12 of Today’s Most Pressing Covid Questions Answered

The race to tame Covid-19 has resulted in a wealth of research, new vaccines and promising treatments that hold out the promise of an end to the pandemic. But many questions remain. Here, Max Nisen and Sam Fazeli, who cover health care and the pharmaceutical industry for Bloomberg Opinion and Bloomberg Intelligence, discuss some of the most pressing ones. The dialog has been edited and condensed.

MN: Do we really need a booster or third shot? What exactly should we expect them to do?

SF: Fortunately, the vaccines that have been studied most – those from AstraZeneca Plc, Pfizer Inc.-BioNTech SE and Moderna Inc.- continue to provide high protection against severe disease or hospitalization for at least six months after two doses. From that perspective, we do not need a third shot. But we are seeing a meaningful drop in the protection against infection. This is expected, given that vaccine-induced antibodies decline with time, and that we’re now grappling with the more contagious delta variant. The real question is whether the protection against severe disease will also start to wane. I think we will see data from Israel on this, as well as from the U.S. Food and Drug Administration at its Sept. 17 meeting. Waning immunity against severe disease could happen if the vaccine always needed a third shot, which wasn’t studied because initial vaccine trials focused on speed. Several highly effective existing vaccines require third shots to generate stronger protection. But because leading Covid-19 vaccines use newer technologies, we don’t really know the best way to dose. It’s possible that third shots may need to be viewed as standard for Covid-19 vaccines, rather than a luxury. Either way, it’s critical that we not oversell the potential benefits of a third shot. Antibody levels will wane again and the risk of infection may rise, but the risk of severe disease and from future variants should be lower.