As the US railroad network grew, so did the chance that smallpox might travel along it. Vaccine hesitancy wasn’t a big issue then, says Wehrman, although there must have been some level of resistance to require the existence of mandates. Companies weren’t soft about it either: According to reporting of the time, unvaccinated workers knew that “they must ‘bare their arm’ now or hunt another job, and they bared.”

But railroad companies didn’t just demand their employees get vaccinated—they also offered opportunities to do so. They provided free vaccines to workers who couldn’t afford them, and to make things even more convenient, they didn’t require the employees to go get the vaccines, but brought the vaccines to them.

Newspaper clippings report on the vaccination trains.
Newspapers report on the vaccination trains.
Image: via Andrew Wehrman
Newspaper clippings report on the vaccination trains.
Newspapers report on the vaccination trains.
Image: via Andrew Wehrman

All aboard the vaxx train

The special convoys, called “vaccination trains,” would typically have a couple of doctors onboard, and stop along every station on the line they were traveling on, inoculating “every section man, switchman, gatekeeper, etc. on the road.” The companies would pay for the programs, and at times vaccinate passengers too.

The requirement didn’t follow a federal mandate, it was a decision by the companies themselves, although much like today, the federal government did require that contractors hire only vaccinated employees.

The vaccines would typically be picked up from the farms where they were produced by infecting cows with cowpox, then using the virus to inoculate humans (this is where the word vaccine has its origin—from the Latin vacca, cow). Whether between Kansas City (Missouri) and LA, from Grand Rapids (Michigan) to Richmond (Virginia), or from Lima (Ohio) to Chicago (Illinois), the trains traveled along all railroad routes, stopping for a couple of hours in each station. “Local communities wanted these trains and their employees to be vaccinated when they arrived in their towns,” says Wehrman.

The mandates could be wide, too. The Pennsylvania Railway company, for instance, demanded in 1943 that as many as 140,000 workers be vaccinated against smallpox in 14 states.

The years at the end of the 19th and beginning of 20th century were a time of strong labor movements, and railroad workers were used to striking to demand better wages, or more safety. “But they did not protest these vaccination efforts,” says Wehrman.

Eventually, the mandates—and the vaccination trains—wound down as did the outbreaks of smallpox in the US, the last of which was recorded in 1948. “It is no surprise that efforts like these led to the eradication of smallpox, because it was such a united effort—public, private, individual,” says Wehrman.

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