Get a fish to teach you chaos theory!

Why does the number e appear in models of exponential growth?

Like any medical drug, vaccines are tested in large-scale randomised controlled trials.

Modelling shows that old and vulnerable people should be prioritised.

We can't say for sure, but everything depends on how many people agree to be vaccinated.

Yes the approved vaccines are safe. If you balance the risks, then taking the vaccine is much safer than taking your chances with COVID-19.

Because the vaccine may not stop transmission of the virus.

The efficacy of vaccines is estimated from trials, using statistical techniques.