Thousands of years ago, variola virus (smallpox virus) emerged and began causing illness and deaths in human populations, with smallpox outbreaks occurring from time to time. Thanks to the success of vaccination, the last natural outbreak of smallpox in the United States occurred in 1949.cdc.com ourworldindata.org How is it transmitted? Humans are infected with the […]

Read More The Historical Smallpox – Its Outbreak and Impacts