What Do Vaccine Efficacy Numbers Actually Mean?

Link: https://www.nytimes.com/interactive/2021/03/03/science/vaccine-efficacy-coronavirus.html

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Excerpt:

Efficacy depends on the details of a trial, such as where it took place. Johnson & Johnson ran trials at three sites: in the United States, Latin America and South Africa. The overall efficacy was lower than that in the United States alone. One reason for that appears to be that the South Africa trial took place after a new variant had swept across that country. Called B.1.351, the variant has mutations that enable it to evade some of the antibodies produced by vaccination. The variant didn’t make the vaccine useless, however. Far from it: In South Africa, Johnson & Johnson’s efficacy was 64 percent.

Efficacy can also change when scientists look at different outcomes. Johnson & Johnson’s vaccine had an 85 percent efficacy rate against severe cases of Covid-19, for example. That’s important to know, because it means that the vaccine will prevent a lot of hospitalizations and deaths.

Author(s): Carl Zimmer, Keith Collins

Publication Date: 3 March 2021

Publication Site: New York Times

What happens if bitcoin succeeds?

Link: https://voxeu.org/article/what-happens-if-bitcoin-succeeds

Excerpt:

In a week when bitcoin is setting records with a market value exceeding a trillion dollars, what would it mean if cryptocurrencies succeed? 

The only reason all the bitcoins are worth a trillion dollars is the expectation of success, as they are not very useful today. Cryptocurrencies must provide some valuable service if they are to justify their high valuation, otherwise holding bitcoin is just like collecting stamps or beanie babies – a minority activity that does not justify the current $51,000 price.

But what is the valuable service that makes bitcoin successful? 

Author(s): Jon Danielsson

Publication Date: 26 February 2021

Publication Site: Vox EU