Silver 22mm.

Smallpox invades Vienna
In 1767, Maria Theresa caught smallpox (She became infected while comforting her pox-stricken daughter-in-law, Maria Josepha (second wife of Joseph II) . So did Josephina of Bavaria, Maria Christina and Albert of Saehsen-Teschen as well as Archduchess Elisabeth. Maria Christina and Albert recovered. Elisabeth, although survived, her beautiful face was irreparably pockmarked. Maria Josepha, from whom the Empress caught the smallpox, also died and this was to have a tragic finale.
When Maria Theresa had recovered, she was ready to prepare for the marriage of her daughter Josephina to the King of Naples. Unfortunately, she demanded that Maria Josephina visited the grave of her recently passed away sister in law, Maria Josepha. Upon Josephina's return, she had caught the smallpox from the tomb and died a few days later. Josephina was only 16 when she died.
This medal was issued to commemorated the Service held on the 22nd July 1767 to give thanks to God for the Empress' survival and also to remember those that perished.