Question

What are vaccines? Who developed the first vaccine?

Answer 1

Hint: Vaccine is something which is related to the immunity of the body. Vaccine contains something which helps humans to gain immunity power.

Complete answer:
Vaccine is a substance which is used to bring up the formation of antibodies and supply power of immunity against one or many diseases, prepared from the agent which causes the same disease, its products, or an artificial substitute, treated to act as an antigen without inducing the disease. It is a substance that helps protect against certain diseases. Vaccines contain a dead or weakened version of a microbe. It helps your system recognize and destroy the living microbe during a future infection.
Each vaccine that you take contains a tiny low amount , or heavily weakened sample of the disease germ (virus or bacteria) or parts of the germ. Examples of such vaccines and diseases include the measles virus, pertussis (whooping cough) bacteria, and tetanus toxoid. Vaccines don't cause disease because the germs are either dead or weakened and therefore the toxoids are inactive.
There are mainly 4 varieties of vaccines:
i.Live-attenuated vaccines.
ii. Inactivated vaccines.
iii. Subunit, recombinant, polysaccharide, and conjugate vaccines.
iv. toxoid vaccines.
The smallpox vaccine was first introduced by physician Edward Jenner in 1796, and it turned out to be the primary successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox failed to catch smallpox and showed that inoculated vaccinia protected against inoculated poxvirus.

Note: Vaccination is the process when a vaccine is made to react with your body (usually by injection). Immunisation is the post effect that happens in your body after you've got the vaccination. The vaccine stimulates your system in such a way that it can recognise the disease and protect you from further future infections.