Today's news about Pfizer's coronavirus vaccination brings hope for an end to the covid-19 pandemic. With an effective vaccine (90% effective as Pfizer has claimed for their vaccine is truly spectacular!), we can finally think about returning to life as before- normal school, yay! (never thought I would say that ever!), even though it will be months or years before a sufficiently large population can be given the vaccine. Nevertheless, it is exciting news for people, as well as for the scientific community that a new vaccine was developed in such an unprecedented short time. In honor of Pfizer's announcement today, I decided to update an older post about vaccines and their history.
A vaccine protects a person from becoming sick when exposed to the virus. How exactly does that happen? When a person gets infected by a virus (any type of virus in general), the white blood cells in their body produces antibodies to fight the virus which helps them recover, and these antibodies remain in the body even after the virus has been defeated. The next time the body encounters the same virus, the antibodies are ready to fight it off before it can take a hold inside the body. That is why person who has got a viral disease usually does not get the same disease again, as their body has built immunity against the virus. A vaccine uses this phenomenon and essentially prepares the body to fight the virus before it has been infected. The way this is done is by taking the virus in a lab and converting it into a form that is not harmful (usually dead or weakened virus), and injecting it into a healthy person in the form of a vaccine. The presence of the inactivated virus tricks the body’s immune system into producing antibodies against the virus, which then protects the person from any subsequent encounter with the real virus, by having the antibodies ready to fight the virus and prevent it from causing any harm. This is a simplified explanation of the traditional vaccine. The new Pfizer and also the Moderna vaccine are a newer form of vaccine called mRNA vaccine, which is slightly different, but that's for another time. Today, I wanted to explore the history of the traditional vaccine.
The development of the modern vaccine is credited to Dr. Edward Jenner in 1796; however, the idea of vaccination is much older. People in India and China knew since the ancient times that most diseases did not re-infect a person who had got it once. It was also well known that drinking snake venom could provide immunity to snake bites, and it was widely practiced by Buddhist monks who travelled extensively through jungles.
The development of the modern vaccine is credited to Dr. Edward Jenner in 1796; however, the idea of vaccination is much older. People in India and China knew since the ancient times that most diseases did not re-infect a person who had got it once. It was also well known that drinking snake venom could provide immunity to snake bites, and it was widely practiced by Buddhist monks who travelled extensively through jungles.
Not only did the concept of vaccines exist in the ancient times, but also the process of vaccination. The vaccination was first developed in ancient India and China for smallpox, which coincidentally is the same disease targeted by Edward Jenner for the first modern vaccine. The earliest reference to smallpox inoculation (also known as variolation) comes from around 1000 CE in China, and the earliest documentation from 1549, but it is believed that it originated as early as 200 BCE in India. It was first administered through the nostrils by blowing powdered smallpox scabs, or scratching smallpox material into the skin, but it soon developed into a method similar to modern vaccination. Using sharp needles, smallpox material was injected into healthy individuals in a practice called "tikah" (meaning "mark" in Hindi) Tikah was a prevalent practice in India until 1802, when it was banned by the British to promote the medical vaccine that had become available in Europe by that time.
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| Old Chinese print showing smallpox vaccination. Image: The History of Vaccines |
The fact that the knowledge of vaccination was prevalent in India long before Edward Jenner's discovery, is evidenced by the existence of letters written by British individuals living in India to their friends and family describing the procedure used in India. For example, one Lady Mary Wortley Montagu wrote a letter to her friend describing smallpox vaccination in India in 1721, followed by many others.
Sources:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078488/
https://www.intechopen.com/books/vaccines-the-history-and-future/introductory-chapter-the-journey-of-vaccines-the-past-and-the-present
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