There are now three vaccines that have been shown to prevent people from developing COVID-19 symptoms. Earlier this month, Pfizer and Moderna announced that their vaccines appeared to give around 95 protection from the coronavirus—now there’s more good news from the team developing a vaccine at the University of Oxford. A trial has shown that the Oxford vaccine, created alongside the drug maker AstraZeneca, stops at least 70 percent of people from developing COVID symptoms—and data suggests that protection can be increased to 90 percent when people are given a low dose of the vaccine followed by a high one. It’s not yet known why that dosing method seems to increase protection. Crucially, the Oxford vaccine is cheaper than the other two and be stored at fridge temperature, which means it can be distributed all over the world. AstraZeneca has agreed to sell the vaccine at production cost to developing nations.