Positive study results have arrived quickly, but the next steps will be slower.
The fast pace at which various laboratories are working on vaccines against Covid-19 carries both promise and peril. On Monday, Moderna Therapeutics Inc. announced the first reported data from human trials, and they are positive. That’s good news, and it arrived sooner than expected. But the parts of the project that lie ahead will be harder to accomplish with speed.
Eight patients who received low and medium doses of the Moderna’s candidate vaccine appear to have developed antibodies capable of neutralizing the new coronavirus. The company didn’t have detailed data on the rest of the 45 trial participants, but all generated at least some antibodies. It was early data from a small study, though, and the limited results don’t prove that the vaccine provides broad and durable protection. Also, while there were no serious safety issues, three patients who received the highest dose of the vaccine briefly suffered modest “flu-like symptoms” after their second injection.
For this vaccine to succeed, tests ahead will need to demonstrate that it can indeed protect people from Covid-19 for an extended period, and that it will prevent substantially more harm than it causes. The bar is especially high for vaccines, because they’re given to healthy people — a Covid-19 vaccine, in particular, could be given to billions of healthy people. Of course, there’s pressure to move quickly. But some parts of the vaccine development process simply cannot be rushed.
Moderna and other companies that have created vaccine candidates in record time have been able to speed early stages of the process — for instance, by compressing animal experiments — and they plan to keep hurrying by testing higher-risk patients earlier than usual and by starting more extensive efficacytrials while smaller safety studies are still running.
