What you need to know about the race to deliver COVID-19 vaccines

Pharmaceutical companies and research centres around the world are working on COVID-19 vaccines, with large global trials of several of the candidates involving tens of thousands of participants well under way. As some companies close in on unveiling their initial findings – with Canadian and European regulators already reviewing early data on some vaccines – here is what we know about the race to deliver vaccines to help end the coronavirus pandemic that has claimed more than a million lives: Who is furthest along? US drugmaker Pfizer Inc with German partner BioNTech SE, US biotech Moderna Inc and UK-based AstraZeneca Plc in conjunction with University of Oxford researchers could provide early analyses of data from their various large trials over the next two months. Johnson Johnson is not far behind. What happens in these trials? The companies are testing their vaccines against a placebo – typically saline solution – in healthy volunteers to see if the rate of COVID-19 infection among those who got the vaccine is significantly lower than in those who received the dummy shot. Neither trial participants nor researchers know who has received the vaccine or placebo until the data is ready for review, or unblinded. The studies rely on subjects becoming naturally infected with COVID-19, so how long it takes to generate results largely depends on how pervasive the virus is where the trials are being conducted. In areas with large outbreaks and community spread, infections will pile up faster. How will we know if the vaccine works? The United States, the European Union, the United Kingdom and the World Health Organization have all set similar minimum standards for effectiveness. Vaccines must demonstrate at least 50 percent efficacy – meaning at least twice as many infections among volunteers who got a placebo than in the vaccine group. style="width: 100%; height: 100%; position: absolute; top: 0; bottom: 0; right: 0; left: 0;">