Source: South China Morning PostAlmost a billion doses of Covid-19 vaccines have now been administered, according to Bloomberg, providing scientists with critical feedback on how the jabs work in the real world, especially as global daily infections move toward record highs and new variants of the virus spread.In Chile and Brazil, studies of vaccinated populations are shedding light on a vaccine from China, after varied results from its clinical trials led observers to wonder how well it would work in protecting large numbers…Read More