- U.K begins 'mix & match' COVID-19 vaccine trials 2GB
- Single Pfizer dose 'highly protective' Newcastle Herald
- New hope in fight against COVID ABC News
- One Pfizer/BioNTech jab gives '90% immunity' from Covid after 21 days The Guardian
- Single Pfizer shot 90 percent effective after 21 days: study Medical Xpress
- View Full coverage on Google News
