A trial of AstraZeneca's experimental Covid-19 vaccine in pigs has found that two doses of the Oxford University-developed shot produced a greater antibody response than a single dose, scientists said on Tuesday.
Research released by Britain's Pirbright Institute found that giving an initial prime dose followed by a booster dose of the shot elicited a greater immune response than a single dose - suggesting a two-dose approach may be more effective in getting protection against the disease caused by the new coronavirus.
The ChAdOx1 nCoV-19 vaccine was originally developed by researchers at the University of Oxford, who are now working with AstraZeneca on development and production.
The vaccine is already in mid-stage human trials, and AstraZeneca has said it hopes to have data showing efficacy later this year. Pigs are a useful research model for this type of vaccine and other trials have been able to predict vaccine outcomes in humans, particularly in studies of flu.