As more and more companies enter the race to create a vaccine that will protect us from the potentially lethal effects of Covid-19, we look at where vaccines come from, how one can be created to tackle Covid-19 and what the hurdles are.
Long before vaccines became a thing, inoculation - which is intentionally introducing a pathogen or antigen that "can cause a disease into a living organism to stimulate the production of antibodies" - was current practice in Africa, China and India some 2,000 years ago.
According to The National Centre for Biotechnology Information (NCBI), smallpox, caused by the variola virus, appeared around 10,000 BC, "at the time of the first agricultural settlements in north-eastern Africa". The virus spread around the world with disastrous effects on humankind; yet, survivors of smallpox seemed to then be immune from the virus.
This is when inoculation, also called variolation, started. "The inoculator usually used a lancet wet with fresh matter taken from a ripe pustule of some person who suffered from smallpox. The material was then subcutaneously introduced on the arms or legs of the non-immune person", says NCBI. And the practice had some degree of effectiveness. Many inoculated people did become...