Meet the 4 frontrunners in the COVID-19 vaccine race

Enlarge / A volunteer receives an injection from a medical worker during the country's first human clinical trial for a potential vaccine against COVID-19 at the Baragwanath Hospital on June 28, 2020 in Soweto, South Africa. It is reported that Africa's first COVID-19 vaccine trial began on June 24 in South Africa. The vaccine, developed by Oxford University's (UK) Jenner Institute, will inoculate 2,000 South Africans. (credit: Getty | Felix Dlangamandla)

Researchers have now reported data from early (and small) clinical trials of four candidate COVID-19 vaccines.

So far, the data is positive. The vaccines appear to be generally safe, and they spur immune responses against the novel coronavirus, SARS-CoV-2. But whether these immune responses are enough to protect people from infection and disease remains an important unknown.

The four candidates are now headed to larger trials—phase III trials—that will put them to the ultimate test: can they protect people from COVID-19 and end this pandemic?