Vaccination to prevent smallpox: mankind's great victory in the fight against viruses

One day in July 2014, a scientist accidentally found six bottles that had been sealed for decades in a cold storage room at the National Institutes of Health in Maryland, USA. All of these bottles were labeled with the word "smallpox". Yes, it was smallpox, a terrible disease that historians called "the greatest slaughtering demon in human history". The discovery of the scientist has brought smallpox, which has withdrawn from the stage of history, back into people's vision.

From its first appearance to its final exit, smallpox lasted for more than 3,000 years. According to conservative estimates, the death toll caused by it will not be less than 300 million! The earliest human record of smallpox can be traced back to ancient Egypt, where a pharaoh who died in 1156 BC showed signs of a rash suspected of smallpox. In the late Ming and early Qing dynasties in my country, when the Qing army entered the country, many people were infected with smallpox due to factors such as climate. Rumor has it that Emperor Shunzhi of the Qing Dynasty died young because of this. The reason why his successor, Emperor Kangxi, was able to stand out in the cruel competition for the throne at the age of only eight is also suspected to be related to his infection with smallpox and recovery. After all, those who have recovered from smallpox have gained lifelong immunity and will not repeat the scene of dying young because of this, which is crucial to the consolidation of imperial power.

Mummy of Ramses V, Egyptian Pharaoh

Smallpox, this terrifying demon, is actually caused by the Variola virus. At first, the smallpox virus may have been just a domestic pox virus that posed no threat to humans, but after a long period of evolution, its pathogenicity changed and became a terrible killer that could kill people. On the one hand, this may be related to people domesticating animals and living with them during the agricultural period. On the other hand, it may also be caused by human contact with wild animals, just like a few people in Central Africa are now infected with monkeypox (a viral zoonosis).

Variola virus

The scary thing about smallpox is the amazing reproduction ability and super infectiousness of the smallpox virus. Even today, when medical technology is advanced, vaccination is still considered the most effective strategy for smallpox prevention and control. In ancient times, once people were infected, they could only leave it to fate. The smallpox virus can lurk in the human body for 7-17 days. In the first week of infection, the virus is mostly active in the body of smallpox patients, and the body will not show obvious symptoms. Around the ninth day, the patient begins to experience symptoms such as headache, high fever and fatigue. After the incubation period, the patient begins to reduce fever and will feel better in a short period of time. At the same time, red rashes will appear on the face, arms and legs one after another. Subsequently, the lesions begin to fester and scab, and become scabies in the third to fourth week, and then slowly peel off.

The smallpox virus can be spread through the air and is extremely contagious. In the first week of infection, the virus content in the saliva of a smallpox patient is the highest and the infectiousness is the strongest. Even after scarring (peeling off), the smallpox virus is still able to transmit and cause disease. There was a case in the United States where a smallpox outbreak in a certain place infected millions of people within a few dozen days. It is not an exaggeration to compare it to the god of death who harvests lives.

Smallpox viruses are divided into three categories: variola minor, variola mediterranean, and variola major. The transmission methods and symptoms of these three types of viruses are exactly the same, and the main difference is the mortality rate. The mortality rates of variola minor and variola mediterranean are relatively low, at 1% and 12% respectively, while the most common variola major virus (orthopoxvirus) is particularly terrifying, causing 25% of patients to die!

Throughout history, smallpox has claimed countless lives. However, the tenacious people did not back down, but instead faced the challenge head-on. The earliest method of preventing smallpox originated in my country and was introduced to Europe in the early 18th century. According to ancient medical books, the "King of Medicine" Sun Simiao first obtained pus from the mouth sores of smallpox patients and applied it to the skin of healthy people to prevent smallpox. In the Ming Dynasty, vaccination against smallpox became popular.

In addition, in the process of "vaccination against smallpox", the name of British doctor Edward Jenner must be mentioned. In 1796, it was he who successfully injected cowpox into an eight-year-old boy, giving him immunity and achieving a major breakthrough in smallpox vaccination. To this day, smallpox vaccines are still made from cowpox virus, most of which have the same antigens as smallpox virus, but are less harmful and will not cause human illness.

Edward Jenner (May 17, 1749 - January 26, 1823)

In 1979, smallpox, which had plagued mankind for three thousand years, was finally eradicated due to widespread vaccination against cowpox. The United Nations World Health Organization even held a special celebration ceremony. In the same year, laboratories around the world agreed to destroy their own smallpox virus samples, with only the Centers for Disease Control and Prevention in Atlanta, the United States, and the Novosibirsk State Research Center for Virology and Biotechnology in Russia retaining a small number of samples for medical research (governments of various countries can keep vaccines that do not contain smallpox virus).

In addition, now, except for a few scientific researchers and medical staff involved in smallpox research, as well as special groups, there are fewer people who are vaccinated against smallpox. The last naturally infected smallpox patient in the world appeared in Somalia, Africa in 1977, and the last smallpox patient was British medical photographer Janet Parker. She was infected with smallpox in a laboratory in 1978, and the head of the laboratory, Professor Henry Bedson, committed suicide.

Smallpox is gone forever. This is not only a reflection of human wisdom, but also a reward for unremitting efforts. The future of mankind is destined to be accompanied by beauty and light.

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