Childhood Vaccination and Immunisation

Question 1

Explain how vaccines work, including cellular mechanics and various Ig subtypes

Answer 1

• Vaccines typically contain some kind of antigen; this is a substance that mimic the presence of a certain infectious agent without the presence of the agent itself
• In response to this, native antigen presenting cells (such as dendritic cells) pick up these antigens, and deliver them to T cells in the Lymph node, thus activating the cellular arm of the immune response
• This triggers corresponding B cells to produce antibodies against the detected antigen, including IgM (first) and IgG antibodies; label + mark for destruction
• The initial antibody response is slow, but since the body develops memory cells, it enables a faster immune response upon secondary exposure, thus providing immunity

Question 2

What are the two main classes of vaccines (excluding MRNA)?

Answer 2

• Killed/inactivated: contains pathogen that is non-viable
• Live attenuated: pathogen is viable, but in a weakened form

Question 3

How does live/killed vaccines affect booster frequency? Why?

Answer 3

• Live vaccines mimic natural infection more closely, and produce a more robust immune response.
• Therefore, they require boosters less often, and the killed/inactive ones tend to need more boosters.

Question 4

How does an immunocompromised patient affect which kind of vaccines we can give them?

Answer 4

• Immunocompromised deal more poorly with pathogens
• Therefore, live vaccines are contraindicated in cases of patients who are immunocompromised0