https://www.cnbc.com/2020/09/22/coronavirus-vaccine-wont-bring-about-a-fairytale-ending-expert-.html
Coronavirus vaccine won’t bring about ‘fairytale’ ending to pandemic, expert warns
Published Tue, Sep 22 2020
The U.S. Food and Drug Administration, for instance, said at the end of June that it expected “a Covid-19 vaccine would prevent disease or decrease its severity in at least 50% of people who are vaccinated.”
“The WHO is hoping to be able to vaccinate 20% of the world by the end of 2021, and that’s already quite ambitious, it’s a huge exercise to vaccinate the world,” he added.
It’s statistically very unlikely that the first one will be the best and what would concern me is that everyone would say: ‘Oh, it’s 50% effective, or 60%, let’s do it,’ and a few months later you might find one that’s 80% effective, or you find that the first one wears off after six months and you need to do boosters again,” he said.