Question

Vaccination for smallpox lasts for lifetime, whereas vaccination for typhoid lasts for 2-3 years. Give reasons.​

Answer 1

• Vaccines like those for smallpox provides long-term immunity whereas the ones for typhoid provides short-term immunity. ​

• In long term immunity, the memory cells in the immune system can generate antibodies for long periods. ​

• Whereas in short-term immunity, the memory cells can generate antibodies only for short-periods. Later, these cells lose their memory. ​