Among them were the English farmer Benjamin Jesty, in Dorset in 1774 and the German teacher Peter Plett in 1791. Jesty inoculated his wife and two young sons with cowpox, in a successful effort to immunize them to smallpox, an epidemic of which had arisen in their town. His patients who had contracted and recovered from the similar but milder cowpox (mainly milkmaids), seemed to be immune not only to further cases of cowpox, but also to smallpox. By scratching the fluid from cowpox lesions into the skin of healthy individuals, he was able to immunize those people against smallpox.Reportedly, farmers and people working regularly with cattle and horses were often spared during smallpox outbreaks. Investigations by the British Army in 1790 showed that horse-mounted troops were less infected by smallpox than infantry, due to probable exposure to the similar horsepox virus (Variola equina). By the early 19th century, more than 100,000 people in Great Britain had been vaccinated. The arm-to-arm method of transfer of the cowpox vaccine was also used to distribute Jenners vaccine throughout the Spanish Empire. Spanish king  Charles IVs daughter had been stricken with smallpox in 1798, and after she recovered, he arranged for the rest of his family to be vaccinated.In 1803, the king, convinced of the benefits of the vaccine, ordered his personal physician Francis Xavier de Balmis, to deliver it to the Spanish dominions in North and South America.
Optic papillitis is a specific type of optic neuritis. Inflammation of the optic nerve head is called "papillitis" or "intraocular optic neuritis"; inflammation of the orbital portion of the nerve is called "retrobulbar optic neuritis" or "orbital optic neuritis". It is often associated with substantial losses in visual fields, pain on moving the globe, and sensitivity to light pressure on the globe. It is often an early sign of multiple sclerosis.Papillitis may have the same appearance as papilledema. However, papillitis may be unilateral, whereas papilledema is almost always bilateral. Papillitis can be differentiated from papilledema by an afferent pupillary defect (Marcus Gunn pupil), by its greater effect in decreasing visual acuity and color vision, and by the presence of a central scotoma. Papilledema that is not yet chronic will not have as dramatic an effect on vision. Because increased intracranial pressure can cause both papilledema and a sixth (abducens) nerve palsy, papilledema can be differentiated from papillitis if esotropia and loss of abduction are also present. However, esotropia may also develop secondarily in an eye that has lost vision from papillitis. Retrobulbar neuritis, an inflamed optic nerve, but with a normal-appearing nerve head, is associated with pain and the other findings of papillitis. Pseudopapilledema is a normal variant of the optic disk, in which the disk appears elevated, with indistinct margins and a normal vascular pattern. Pseudopapilledema sometimes occurs in hyperopic individuals. Workup of the patient with papillitis includes lumbar puncture and cerebrospinal fluid analysis. B henselae infection can be detected by serology.