Question

Your friend tests her snake-wrangling skills on an eastern diamondback rattlesnake and is bitten and injected with venom. In the emergency department, doctors administer the anti-venom (antivenin) CroFab, which contains antibodies to the toxins in the snake venom. Is this an example of active or passive immunity? (explain why). Will this result in long term protection against future rattlesnake bites? Explain.  

Answer 1

Giving antivenom is an example of passive immunity because it contains antibodies.

Transfer of antibodies directly comes under the category of passive immunity because there is no role of immune system fighting against the pathogen and antibodies are given ready made.

Passive immunity is not long lasting and is effective for short period of time.

In active immunity body's own immune system fights against the pathogen and there is formation of memory B and memory T cells. These memory cells help in long term protection and prevents the infection in body by same pathogen. It's duration varies and in some cases it may last life long .

On the other hand ,in passive immunity directly antibodies are given and there is no involvement of body's immune system . That'swhy there is no formation of memory B and memory T cells. Which is the reason of short term effectiveness of passive immunity . It may last for few days or few weeks. In this case , it will not give long term protection against future rattlesnake bites.