What happens if a coronavirus vaccine is never developed? It has happened before

As countries lie frozen in lockdown and billions of people lose their livelihoods, public figures are teasing a breakthrough that would mark the end of the crippling coronavirus pandemic: a vaccine.

from CNN.com - RSS Channel - App International Edition https://www.cnn.com/2020/05/03/health/coronavirus-vaccine-never-developed-intl/index.html
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