Thinking of mixing and matching COVID-19 vaccine booster shots? There doesn't seem to be much point - ABC News
The Straits Times - How effective are Pfizer and Moderna's booster shots? Here's a look how the 2 combinations further reduce the risk of Covid-19 infection. https://str.sg/3GDQ | Facebook
![Region of Waterloo Public Health on Twitter: "Mixing vaccines is safe and effective. If you had Moderna/Pfizer, you can safely take either for your 2nd dose. If you had AstraZeneca, you can Region of Waterloo Public Health on Twitter: "Mixing vaccines is safe and effective. If you had Moderna/Pfizer, you can safely take either for your 2nd dose. If you had AstraZeneca, you can](https://pbs.twimg.com/media/E4g6FU3WEAY1psK.jpg:large)