Britain has become the first Western nation to grant approval for a coronavirus vaccine—and the first shots could be given within days. The country’s medical regulator announced early Wednesday that the Pfizer/BioNTech jab, which offers up to 95 percent protection against COVID-19, is safe and can be rolled out to the public immediately. Immunizations are expected to start next week, and those who need it most—such as the vulnerable and elderly—will be first in line. A batch of 800,000 doses will arrive in the U.K. in the coming days. The two-shot vaccine is also being reviewed by the Food and Drug Administration in the United States, where authorization is expected later this month.