Bypassing clinical trials for a potential SARS-CoV-2 vaccine would be "catastrophic," says Science Advances deputy editor Douglas Green in this Editorial. Instead, it's vital to take time to ensure any vaccine candidate's safety and investigate potential adverse effects, he says. A vaccine able to trigger strong neutralizing antibody responses in clinical tests will still not be ready for widespread implementation without comprehensive safety tests. For example, vaccines must be examined for causing an effect known as antibody-dependent enhancement (ADE), whereby vaccine-induced antibodies that bind to the virus also attach to the body's cells, facilitating infection of these cells - a concerning phenomenon that has been observed in vaccines against dengue, Ebola, HIV, and feline coronavirus. Ethical accelerated testing on humans should not be ruled out completely, but extreme risks must be weighed against potential benefits, Green says. There are currently 95 vaccines in development against SARS-CoV-2, with most expected to clear Phase I and two experimental vaccines already moving into Phase II trials.