• Eight segmented pieces of RNA, a structure that permits the introduction of new RNA. This is called genetic reassortment. This is called antigenic shift.
• The hemagglutinin spikes which provide viral attachment to cell membranes. They are strain specific antigens that mutate frequently because of inefficient proofreading by RNA polymerase.
This is called antigenic drift.
• And ditto for the Neuraminidase spike, which provides release from cell membranes

• Type A: The Main Player
– It causes annual outbreaks
– It mutates easily. This is called antigenic drift and is why the vaccine changes every year, usually causing an epidemic affecting 10% to 20% of the population.
– It is susceptible to RNA reassortment, where a portion of avian influenza RNA is inserted. This is called antigenic shift and is responsible for pandemics or infections occurring over a wide geographic area and affecting a high proportion of the population.
– It is characterized by the H and N antigens.

• 1918: Possibly an avian influenza strain that adapted to infect humans.
• 1957 and 1968: A human/avian reassortment strain.
• 2009: A human/swine/avian reassortment virus.

• Person to Person
• Viral shedding—day prior to symptom onset —5-7 days after symptom onset
• Can get from pigs not from eating pork

• EVERYONE >6months and older
• IM (inactivated) Intranasal (live attenuated)
• Intranasal NOT USED IN: chronic disease, immunsuppression, pregnancy, prior h/o GB from prior vaccinations
• SMALL AMOUNTS of EGG in each
• Anaphylaxis is rare
• What do we carry?
• Efficacy: 50%-80% rate of protection if closely matched

Three strains: (always A-A-B) this year:
-A-California h1n1”like” virus
-APerth h3n2 ”like” virus
-B Brisbane
Every year the strains are selected based on worldwide surveillance for most active strains – a little guess-work involved

• Fevers, Myalgias
• TEST—flu swab, nasal

• Oseltamivir: TAMIFLU
• Zanamavir: Ralenza
• Rx for Type A &B
• Low levels of resistance
• In 48 hours TREAT (as per Dr. Chung)
• PPX: NH Residents within 48 h, Case by case
Babies, pregnant women

• HOW TO ORDER THE VACCINE
• HOW TO BILL FOR IT
• ALLERGIES: EGGS!!! Relative
Contraindication
• No inhaled form of vaccine here
• Rapid antigen—Nasal swab in 6 th floor
Micro
• ?????s