#CBG_Thread

Long before Serum Institute of India was setup, the mesmerising hills of Kasauli, HP made first Indian vaccines.

But what connects smashed sheep brains, horse blood, an idyllic hill station in Himachal and and the deadly Rabies virus ?

Read on.
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Rabies has the highest fatality rate for any viral infection in humans. Almost 100%. Death is painful and horrific.

Thankfully Anti Rabies vaccine given in time prevents deaths these days. But this wasn't the case always....

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David Semple was an Irish bacteriologist posted in India. The British needed a domestic institute to develop vaccines for British soldiers and officers.

In 1905, Pasteur Institute was setup in the hills of Kasauli in Himachal with David Semple as his first director. 3/n

To make a vaccine, you need inactivated/weakened virus but that can only be found in patients (humans and animals) who can bite and infect you.

David Semple found that unlike many other animals, sheep don't bite further when infected with rabies virus. 4/n

So Semple infected sheep with rabies virus. Once the virus reached sheep's brain, sheep was killed, its brain removed and smashed to extract virus.

He tried it with rabbits too, but finalized sheep for ease of domestication and management.

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The extracted virus has to be treated with a serum which is collected from the blood of horses (typically taken from the neck).

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The Rabies vaccine thus produced had to be injected in the stomach of patient bitten by dog. And it needed almost 23 shots. Not to mention this vaccine also had significant risk of paralytic attack. 7/n

Thankfully, the modern rabies vaccine is derived from cell culture of either duck embryo or human cells. It is far more safer and doesn't require 23 shots in the stomach anymore. 8/n

Pasteur Institute in Kasuali is now called Central Research Institute. It has played an important role in developing domestic vaccines for polio, measles, snake bites, DPT etc.

It also doubled up as Covid testing centre last year.

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