What was the estimated date of the smallpox vials that were found?

The estimated date of the smallpox vials that were found is tied to the timeline of when smallpox was declared eradicated. Smallpox was officially declared eradicated in 1980 following a successful worldwide vaccination campaign. Prior to this, the last natural outbreak occurred in 1977. The production and storage of smallpox viruses continued in laboratory settings even after its eradication, particularly in the 1970s, and some strains were kept in controlled environments for research purposes.

Choosing the 1950s aligns with the period when smallpox vaccines were commonly distributed and when many countries were still actively managing the disease. During this time, there was a focus on containment and research efforts regarding smallpox, which would likely lead to the storage of vials for study.

While the 1940s did see the development of vaccination techniques and increased public health efforts, it was during the 1950s that various important advancements and decisions regarding smallpox and its research were formalized. The estimate for the discovery of vials likely reflects this era's involvement in managing smallpox, making it a plausible date.