The word ‘Vaccine’ has been derived from a Latin word having meaning

Correct — C, (c) Cow. The word 'vaccine' comes from the Latin VACCA, meaning cow, through the adjective vaccinus, 'of or from the cow'. The link is Edward Jenner's work of 1796. Jenner had noticed that dairymaids who caught cowpox — a mild disease of cattle that they picked up from the udders of infected cows — did not go on to get smallpox, which was then one of the great killers. In May 1796 he took material from a cowpox lesion on the hand of the dairymaid Sarah Nelmes and inoculated it into an eight-year-old boy, James Phipps; when he later exposed the boy to smallpox matter, the boy did not develop the disease. Jenner called the cowpox agent variolae vaccinae, literally 'smallpox of the cow', and the procedure took its name from that phrase. Louis Pasteur later proposed extending the words 'vaccine' and 'vaccination' to every preventive inoculation of this kind, explicitly in Jenner's honour, which is why a term built on the Latin word for cow is now used for preparations that have nothing to do with cattle.

Why the others are wrong

• (a)Antibody — 'Antibody' is not the root of 'vaccine', and it is not even a Latin-derived word in the way the stem describes. It is a modern coinage of the late nineteenth century, an English rendering of the German Antikorper, from the era when Behring and Kitasato showed that the serum of an immunised animal carried something that neutralised a toxin. The option is offered because antibodies are what a vaccine ultimately provokes, so the association is real; but the question is about ETYMOLOGY, not about mechanism. Confusing what a word means with where a word came from is exactly the slip this option is built to catch.
• (b)Immunity — 'Immunity' is the outcome a vaccine produces, not the source of its name. Its own Latin root is a different word entirely — immunis, meaning exempt or free from a public burden or tax, which passed from the language of Roman civic obligation into medicine as 'exempt from disease'. So a candidate who picks this option has the right language and the wrong word. This is the most tempting of the three wrong options precisely because the sentence 'vaccine comes from a Latin word meaning immunity' sounds entirely reasonable until you know the actual history.
• (d)Guinea pig — The guinea pig has nothing to do with the word 'vaccine'. This option trades on the English idiom of being 'a guinea pig' for an experiment, which links loosely to the idea of testing a vaccine on a subject, and on the fact that guinea pigs really were used as laboratory animals in later immunological work. But neither connection touches the word's origin, and 'guinea pig' is not a Latin term at all — the animal is a South American rodent that reached Europe only in the sixteenth century, long after classical Latin. The option is a pure decoy that tests whether a candidate is guessing from atmosphere rather than from knowledge.

Vaccination works by teaching the immune system to recognise a pathogen before it is ever met in earnest. A vaccine presents the immune system with an antigen — a killed or weakened organism, a purified protein, a toxoid, or nucleic acid instructions for making one — which provokes an immune response and, crucially, leaves behind memory B and T cells. On a later real encounter the memory response is faster and much stronger, so the infection is cleared before it causes disease. Because this is the body making its own response, it is ACTIVE immunity, slow to develop but long-lasting; giving ready-made antibodies instead, as with an anti-tetanus or anti-rabies serum or the antibodies a baby receives across the placenta and in breast milk, is PASSIVE immunity, immediate but short-lived. Jenner's cowpox procedure of 1796 was the first vaccine and the model for all of them: cowpox and smallpox viruses are close enough that immunity to one protects against the other. That is also why smallpox became the first and so far only human disease to be eradicated, declared so by the World Health Organization in 1980. India's Universal Immunisation Programme and its Mission Indradhanush drive descend directly from this idea.

Key facts

• 'Vaccine' derives from Latin vacca, meaning cow, through vaccinus, 'of or from the cow'.
• Edward Jenner performed the first vaccination in 1796, using cowpox material from the dairymaid Sarah Nelmes on the boy James Phipps.
• Jenner named the cowpox agent variolae vaccinae, 'smallpox of the cow', which is the phrase the word comes from.
• Louis Pasteur proposed extending 'vaccine' and 'vaccination' to all preventive inoculations, in honour of Jenner.
• Smallpox is the only human disease so far eradicated worldwide; the World Health Organization declared it eradicated in 1980.
• A vaccine produces ACTIVE immunity — the body makes its own antibodies and memory cells; ready-made antibodies give PASSIVE immunity, which is immediate but short-lived.
• The Latin root of 'immunity' is a different word, immunis, meaning exempt or free from a public burden.

Common traps

• Answering with what a vaccine DOES (produces immunity, produces antibodies) when the question asks where the WORD came from.
• Assuming any Latin-sounding medical term must trace to a Latin word for the medical concept itself. Many trace to ordinary objects and animals.
• Crediting the discovery of vaccination to Pasteur. Pasteur generalised and named the field; Jenner performed the first vaccination in 1796.
• Confusing cowpox with smallpox. Cowpox is the mild cattle disease Jenner used; smallpox is the killer it protected against.
• Treating the unpunctuated English stem as a misprint. It is printed as a sentence-completion line and simply has to be completed.

• practice — not a real PYQ

  The first successful vaccination, performed by Edward Jenner in 1796, used material taken from a case of

  • (a)smallpox
  • (b)cowpox
  • (c)chickenpox
  • (d)rabies

  Answer(b) cowpox

• practice — not a real PYQ

  Which one of the following is an example of passive immunity ?

  • (a)Immunity produced by the BCG vaccine
  • (b)Immunity following recovery from measles
  • (c)Antibodies passed from a mother to her infant in breast milk
  • (d)Immunity produced by the oral polio vaccine

  Answer(c) Antibodies passed from a mother to her infant in breast milk