It’s possible the first vaccine may not even be 50 percent effective. But that will still help to bring the coronavirus pandemic under control.

This year has brought an unprecedented race to develop, test, and manufacture vaccines and treatments for SARS-CoV-2, the virus that causes Covid-19. Experts say they’ve never seen anything like it: the international collaboration, the round-the-clock work, the scope and scale of more than 150 different vaccines already in the pipeline mere months after the novel virus emerged. And several of those vaccines seem promising. “I feel cautiously optimistic, as a scientist, that we will have a safe and effective vaccine,” Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said last month. “I believe it will happen, and it will happen likely by this end of the calendar year.”

But as vaccines start emerging in the coming months, we may be confronted with a new issue: What if the vaccines are only mediocre? Will we be able to control the virus—and, perhaps more importantly, convince people they should get vaccinated, now and in the future—if the first Covid-19 vaccines are not actually that effective? Read more at The New Republic.