based on the info amani3 posted I would say if they fly with this they are relying on the 12 days to appear and therefore making fear mongering more believable and line up the needles. which they may say is a SPox vax but how do we really know?

In 5% to 10% of smallpox patients, more rapidly progressive, malignant disease develops, which is almost always fatal within 5 to 7 days. In such patients, the lesions are so densely confluent that the skin looks like crepe rubber; some patients exhibit bleeding into the skin and intestinal tract. Such cases are difficult to diagnose, but they are exceedingly infectious. https://wwwnc.cdc.gov/eid/article/5/4/99-0415_article

Interesting article from Cambridge talks of the temps the pox operate/live in. https://www.cambridge.org/core/journals/epidemiology-and-infection/article/effect-of-temperature-on-the-growth-of-pox-viruses-in-the-chick-embryo/D590EC4C6734FC452D19BF72FF1AF219

Finally its also odd to me that Vaccina is the name for smallpox