Pfizer’s vaccine announcement is good news. These are just preliminary results.

Remember, for most infectious diseases in the last century, the specific medical intervention (such as vaccines) have come only after the rates of death have dropped significantly and have flattened out - per the historical data.

That doesn't mean that medicines were not effective or necessary. But modern medicine was not the primary force that caused infectious diseases to go away, at least in the past.

... based on the research by British physician and historian Thomas McKeown in 1966 and his book The Origins of Human Disease Vaccine. Also by Christakis, Nicholas in Apollo's Arrow. Images from Wikipedia and Apollo's Arrow.