The US Centers for Disease Control and Prevention (CDC) updated its list of the riskiest countries for travel due to increasing cases of Covid-19. Curiously, vaccination has had totally the opposite effect to what had been expected: 12 of the 13 countries on the Johns Hopkins list of the most vaccinated are currently listed by the CDC as “high” or even “very high” SARS-Cov-2 travel risk.The CDC distinguishes between five risk levels: very high, high, moderate, low, and unknown. On August 2, the CDC stated: “Avoid travel to these destinations. If you must travel to these destinations, make sure you...