Vaccines are a crucial tool in the fight against COVID-19, so it’s great news that the U.K. on Tuesday became the first country to begin mass inoculations using a new shot developed by Pfizer Inc. and BioNTech SE.
This vaccine and another developed by Moderna Inc. are set for early approval in the U.S. soon, and there are a handful of additional vaccines on the way. But even if they are as effective in the real world as they look in clinical trials, they can’t change the course of the pandemic overnight, and may not be able to entirely stop the spread of the virus. We need reinforcements.
It will take months for COVID-19 vaccines to reach a large enough percentage of the population to create "herd immunity” — and that’s assuming they win the public’s trust and the vaccination effort goes smoothly. Manufacturing enough doses may not be as easy as the headline deals with various countries suggest. There are also questions around how long immunity to COVID-19 may last. And vaccines may come up short in frail or older people, especially those with preexisting conditions.