Bill Gates talked about the COVID-19 vaccine.br According to Gates the "final hurdle" to distributing a COVID-19 vaccine will be ensuring that people decide to take it.br Gates said testing vaccine candidates with a wide variety of populations and age groups can prove challenging.br Still, Gates believes that "a lot" of people will take a vaccine when one becomes available.br According to Business Insider the billionaire believes herd immunity can be achieved if 70 to 80 of people take the vaccine.