Question

Which one of the following is NOT a live vaccine?

• A. OPV
• B. BCG
• C. Hib vaccine
• D. Ty 21a against Typhoid

Hint:

Ask which of these four is made only from a piece of the bacteria's surface, not a weakened living germ.

Answer 1

The Correct Option is C

Live vaccines contain a weakened but still living form of the organism, while other vaccine types use only a piece of the organism, like a polysaccharide or protein, with nothing alive in the shot.

1. OPV: Made from live, weakened poliovirus, so it is a live vaccine.
2. BCG: Made from a live, weakened strain of Mycobacterium bovis, so it is a live vaccine.
3. Hib vaccine: Built from the capsular polysaccharide of Haemophilus influenzae type b, usually joined to a carrier protein. There is no living organism in it at all, so it is a conjugate (subunit) vaccine, not live.
4. Ty21a against typhoid: An oral vaccine made from a live, weakened strain of Salmonella typhi, so it is live too.

Three of the four options use a living, weakened organism. The Hib vaccine instead uses just a piece of the bacterium's surface, so it stands apart as the non-live one.

Let's summarize:

• OPV, BCG, and Ty21a are all live attenuated vaccines.
• The Hib vaccine is a polysaccharide-protein conjugate vaccine with no live organism.

So the vaccine that is not live is the Hib vaccine.