mix-and-match vaccines

 The latest tightening of the regulations governing the distribution of AstraZeneca vaccine following its association with a rare thrombosis has prompted the thought that perhaps the people who had the first dose of AZ might be able to get Pfizer as their second dose.  Initially we were warned by health authorities against doing this but gradually the message has changed to one that is quite positive. Not only does it help us keep up the speed of vaccination in the community, but it turns out the two vaccines combined give the individual a potent immune response and thus an increased protection against the virus. We may well be getting a different vaccine again as a booster shot.  Approval to mix and match the vaccines in Australia has yet to be given.