SSC CGL 2024 Tier-I · 9 September 2024, Shift 3 · General Awareness · Question 24 of 100

Text as printed on a candidate's response sheet for this shift; answer per SSC's tentative key as marked on that sheet. Solution last reviewed 6 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. The questions and options here are reproduced as printed on a candidate's own response sheet for this shift — the Commission's text, unchanged. Each answer is SSC's tentative key as marked on that sheet; SSC allowed challenges to it and never publishes a final key. The solutions are written by UnlockIAS.

Which of the following is an inactivated (killed) polio vaccine developed in 1952?

(a)HDCV vaccine
(b)Salk vaccine
(c)TAB vaccine
(d)Imvanex vaccine

Answer

Why

Correct — B. The Salk vaccine is the inactivated polio vaccine: poliovirus killed with formalin and given by injection. Jonas Salk developed it in 1952 and it was licensed in 1955 after mass field trials.

The contrast to hold is with Sabin's oral vaccine, which uses live attenuated virus and is given as drops.

Why the others are wrong

(a)
HDCV vaccine — HDCV, the human diploid cell vaccine, is used against rabies. The disease is wrong before the killed-or-live question even arises.
(c)
TAB vaccine — TAB is an inactivated vaccine, but against typhoid and paratyphoid A and B. The stem needs a polio vaccine, so being killed is not enough.
(d)
Imvanex vaccine — Imvanex is a modern smallpox and mpox vaccine, decades younger than 1952 and aimed at a different disease entirely.

Concept

Vaccines split into two broad kinds. An inactivated vaccine uses killed pathogen and cannot replicate in the body. A live attenuated vaccine uses a weakened strain that does replicate, usually giving stronger and longer immunity.

Polio has one of each. Salk's IPV is injected and killed. Sabin's OPV is oral and live attenuated, which made it cheap to deliver in mass campaigns.

That delivery advantage is why oral drops carried India's Pulse Polio campaigns.

The stem tests two things at once: killed against live, and which disease. Both TAB and Salk are killed vaccines, so only the disease separates them.

Key facts

The Salk vaccine is an inactivated polio vaccine given by injection.
The Sabin vaccine is a live attenuated oral polio vaccine given as drops.
India was certified polio-free by the WHO in 2014.

Study next

Live attenuated versus inactivated vaccines and how each is administeredPulse Polio Immunisation and India's polio-free certificationThe Universal Immunisation Programme and the diseases it covers

Common traps

Choosing TAB because it is also an inactivated vaccine, while ignoring that the stem says polio.
Swapping Salk and Sabin, when the injected killed vaccine is Salk and the oral live one is Sabin.

Vaccine stems in this cycle turn on matching a named vaccine to its disease or to its type. Learn Salk and Sabin as a pair, because a stem can key on the route of administration rather than on the year.

Related PYQs

No directly related past PYQ was found.