A New Wave of Vaccines Is Coming, and They’re Not All Also-Rans

The Covid-19 vaccine rollout has given drugmakers the kind of brand-name shorthand usually reserved for more mundane consumer products: People talk about getting Pfizer, Moderna, J&J, or Astra much as they might reach for a Kleenex or a Popsicle. And those companies have contracts to provide billions of doses, appearing to leave little room for other entrants. So why are dozens of hopefuls still working on shots?

The answer is that while early leaders stand to book immense profits, the problem is big enough—and the continuing challenges daunting enough—to leave room for at least a few more companies. The offerings of two that got to the market quickly, AstraZeneca Plc and Johnson & Johnson, have been linked to rare blood clots, slowing their rollout. The handling requirements and high cost of the Moderna and Pfizer-BioNTech messenger RNA vaccines mean governments in poorer places would welcome a cheaper, easier-to-ship alternative. And the rise of new variants opens the door to shots that target the evolving coronavirus. “While we’re thrilled with the vaccines that we have, and we’re so lucky that these vaccines turned out to have such high efficacy and a good safety profile, we can improve further,” says Soumya Swaminathan, the World Health Organization’s chief scientist.