Smallpox, monkeypox and vaccination - what you need to know

Worldwide collaboration throughout the 20th century led to the complete eradication of smallpox, with the last case being registered in 1977.

Smallpox (pox) is a highly contagious disease caused by the Variola virus. The disease is characterised by a severe disease course, high fever, a rash on the skin and mucous membranes. Those infected can end up with scars and partial or complete loss of vision. Mortality ranges from 20% to 40% (with some epidemics reaching 90%). People who’ve had smallpox have a strong natural immunity to the disease going forward.

How did the world manage to eradicate such a highly infectious and deadly disease? Vaccination. In 1796, The British doctor Edward Jenner discovered that by infecting people with a much more mild virus called cowpox they were conferred immunity against the much deadlier smallpox virus. In 1958 the World Health Organisation (WHO) began a global vaccination programme using a modern vaccine. By 1980, the WHO declared smallpox completely eradicated and recommended ended planned vaccination for the virus. Only two samples exist of the smallpox virus, one in the Russian State Scientific Centre “Vector” and the other in the American Centres for Disease Control and Prevention.

Monkeypox is a rare infectious disease caused by Orthopoxvirus (part of the family Poxviridae). It is not as infectious as smallpox, and mainly distributed in remote areas of Central and West Africa. Symptoms of monkeypox are nausea, fever, rash, itching, muscle pain and skin lesions. Most cases present in a mild form of the disease, but severe cases are possible. The mortality rate ranges from 1% to 10%. The virus is transmitted by airborne droplets or close physical contact with the infected person or their belongings.

Cases outside the region are usually related to travel. An outbreak of monkeypox is currently occurring in the UK, Europe and North America - with the most cases being detected in the UK.

Will the smallpox vaccine help against monkeypox? In the USSR, vaccination against smallpox was mandatory until 1980, in the UK and USA their programmes ended in 1971 and 1972 respectively. Experts say that the immunity from these vaccinations will protect against other pox viruses, including monkeypox.

Monkeypox is part of the Orthopoxvirus family. Other viruses in this branch include, human smallpox, cowpox, racoonpox and more. These viruses are all very similar to each other, so the vaccines used previously protects against these various pox viruses - via cross-immunity.

Specialists are not yet calling for global vaccination at this time, rather asking people at higher risk to come forward and get vaccinated. The vaccine can also be used as post-exposure prophylaxis for those who have been in contact with an infected individual. For everyone else the advice is to avoid contact with infected individuals, observe good hygiene standards, and consult your healthcare professional at the slightest suspicion of infection.