10 NOVEMBER 2019
Why was eradicating smallpox successful?
Smallpox is the only human disease that has been eradicated. The World Health Organisation (WHO) announced in 1980 that “Smallpox is dead!”. This has been the outcome of the 13-year campaign launched in 1967 by WHO to fight smallpox. It is estimated that up to 15 million smallpox cases occurred each (!) year. Smallpox had a global death toll of 300-500 million during the 20th century alone and it has been characterised as one of the deadliest diseases known to human history alongside malaria, tuberculosis and plague. Interestingly, there is evidence suggesting that the first confirmed smallpox cases and related deaths date back to the New Kingdom of Egypt, around 1570-1085 BC. This was supported by the archaeological evidence of three mummies (including Pharaoh Ramses V, 1157 BC) that, due to mummification, have their skin preserved, which shows the presence of pustules. However, why was it even possible to eradicate smallpox and who was the paradoxically so-called “unethical” pioneer behind this achievement?
To begin with, smallpox is a highly transmittable disease, since it can spread from person to person through infective droplets during close contact with patients, e.g. coughing, sneezing. Therefore, large groups can be easily affected when many people assemble together, especially in urban centres. Symptoms primarily include fever, vomiting and pustules (skin rashes) covering the entire body of the patients. Prior to the discovery of vaccination, doctors would perform inoculation in order to immunise people against smallpox. This method was carried out by rubbing or inserting smallpox powder or fluid from pustules (deriving from patients) into superficial skin scratches of unaffected people.
The saviour that liberated humanity from the scourge of smallpox emerged many centuries later. Edward Jenner was an English surgeon and the person responsible for the discovery of vaccination for smallpox. Jenner was born in Berkeley, Gloucestershire, England in 1749 and was apprenticed at the age of 14 to a local surgeon for seven years. He, then, moved to London to complete his medical training, but returned back in Berkeley in 1772 at the age of 23 as a permanent resident and doctor. Like all other doctors of the time, Jenner performed inoculation to protect his patients from smallpox.
Nonetheless, it was rumoured, at that time, that people, like dairymaids, who caught cowpox showed immunity, resistance to smallpox. Cowpox is a nonlethal disease of cows that is caused by the cowpox virus, closely related to the virus causing smallpox. On May 1796, a dairymaid, called Sarah Nelmes, was diagnosed with cowpox and confirmed that one of the cows, had indeed cowpox. Then, Edward Jenner performed the first ever vaccination. He chose the son of his gardener, an 8-year old boy called James Phillips, as his subject. Jenner made some superficial scratches to his arm and injected into them material from the pastures of Sarah Nelmes’ hand causing him cowpox. Eventually, after young James recovered from cowpox, Jenner injected James with smallpox in June 1796 and as he anticipated cowpox provided protection against smallpox and so James remained healthy. Even though many people initially disputed Edward Jenner’s work, vaccination with cowpox was made mandatory in 1853 (in England).
Even though Edward Jenner used a human being to perform his experiment, it is believed that he saved more lives than any other person in human history. It took us 184 years to win the fight with smallpox, but as already stated above, smallpox has been eradicated since 1980 and is only kept in two locations under WHO supervision. This stride of humanity can be ascribed to five main reasons: 1) smallpox cannot be transmitted by animals, 2) there were rare subclinical cases, namely only infected people showed the symptoms, 3) smallpox can be only caused by one virus, 4) the vaccine provides lifelong immunity and 5) governments showed strong commitment.
- Image, source: https://commons.wikimedia.org/wiki/File:Edward_Jenner2.jpg