Mar
17
2021
Vaccines approved so far in the United States have been highly effective not just against preventing symptomatic infection but more importantly against severe Covid leading to hospitalization and death, and also – we are learning – against asymptomatic infection which means vaccination cuts down on spread of the disease. We just do not know how long this protection lasts because not enough time has passed yet to make this determination.
That’s a problem for policymakers as they consider whether to open up travel without testing or quarantine to those who have been vaccinated., so we don’t know how long ‘vaccine passports’ should be valid.
