MADRID, May 18 (Reuters) - A Spanish study on mixing
COVID-19 vaccines has found that giving a dose of Pfizer's
drug to people who already received a first shot of
AstraZeneca vaccine is highly safe and effective, the
researchers said on Tuesday.
The so-called Combivacs study, run by Spain's state-backed
Carlos III Health Institute, found the immune response in people
who received a Pfizer shot was between 30 and 40 times greater
than in a control group who only had AstraZeneca dose.
Few serious side effects were reported among the 600
participants, the authors said.
(Reporting by Nathan Allen, editing by Inti Landauro)
Astrazeneca (AZN)
