Britain on Thursday launched a new clinical study to determine the effects of using different Covid-19 vaccines for the first and second dose, AstraZeneca’s vaccine for one dose and Pfizer-BioNTech’s vaccine for the other.
The study will also gather immunological evidence on different intervals between the first and second dose for a mixed-vaccine regimen against control groups when the same vaccine is used for both doses, the UK’s Department of Health and Social Care said in a statement.The 13-month study in which over 800 patients are expected to take part will monitor the impact of the different dosing regimens on patients’ immune responses, which have the potential to be higher or lower than from the same dose regimen.