As the possibility of getting a Covid-19 jab will soon become a reality for some, questions have been raised about how the vaccine works.

We asked researchers David Manheim, Merrick Pierson Smela and Ginny Schmit from 1DaySooner, an international non-profit organisation that advocates on behalf of Covid-19 trial volunteers, for answers.

AstraZeneca is a two-dose vaccine. Will all the vaccines we’ll be getting be two-dose vaccines? If so, why do we need two doses?

All approved vaccines (Moderna, Pfizer/BioNTech, Oxford/AstraZeneca, SinoVac, Sinopharm) are two-dose vaccines. Johnson & Johnson is developing a one-dose vaccine, but it has not yet finished clinical trials.