ABIO 375 - Vaccines 2

What type of vaccine is varicella?

Live attenuated

When is varicella given?

~1 year of age; 4-6 years

Why is varicella given around 1 year?

Maternal antibodies fade around 12 months; early childhood exposure

Why are 2 doses of varicella required?

Increases effectiveness (~81-86% → ~98%); ensures immunity in non-responders

How long does varicella protection last?

Long-lasting; strong immune memory (live vaccine)

What type of vaccine is MMR?

Live attenuated

When is MMR given?

~1 year; 4-6 years

Why is MMR given around 1 year?

Maternal antibodies decrease; measles highly contagious, so early protection is important

Why are 2 doses of MMR given?

Ensures immunity in >97%; covers non-responders

How long does MMR vaccine usually last?

Long-term, often lifelong protection

What type of vaccine is flu (most common)?

Inactivated

When is flu given?

Annually

Why is flu given yearly?

Antigenic drift; new strains each year; immunity decreases

What is antigenic drift?

Frequent viral mutation leading to new circulating strains

What type of vaccine are Pfizer and Moderna (COVID)?

mRNA

Why does COVID require multiple doses?

Not a whole-virus vaccine; immunity decreases; variants emerge

Why do COVID vaccines require boosters?

Immunity wanes over time; boosters restore protection

What type of vaccine is HPV?

Recombinant/subunit

When is HPV given?

Ages 11-12

Why is HPV given at ages 11-12?

Before sexual exposure; strong immune response in preteens; cancer prevention

What does HPV vaccination prevent?

Cervical and other HPV-related cancers