Source: Njoku JC and Hermsen ED.
Influenza. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG,
Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=8002170.
Accessed June 26, 2012.
- Viral illness associated with high mortality and hospitalization
rates in persons >65 years.
- Transmitted person to person via inhalation of respiratory
- Hemagglutinin allows virus to enter host cells.
- Incubation period: 1–7 days (average 2 days)
- Children infectious for longer period of time than adults.
- Viral shedding persists for weeks to months if immunocompromised.
- Immunity occurs through antibody development directed at surface
antigens, particularly hemagglutinin.
- Immunity to one subtype does not confer protection against
other subtypes or types.
- Seasonal epidemics result in 25–50 million cases,
~200,000 hospitalizations, and >30,000 deaths each year in the United
- Overall, more people die of influenza than
of any other vaccine-preventable illness.
- Deaths often result from:
- Secondary bacterial
- Primary viral pneumonia
- Exacerbations of underlying comorbidities
- Types A, B, and C affect many species.
- A and B viruses cause disease in humans.
- Primary prevention
- Vaccination primary
means of influenza prevention.
- Infection control measures to limit spread of influenza
- Hand hygiene
- Basic respiratory etiquette (cover your mouth when coughing
and throw soiled tissues away)
- Contact avoidance
- Annual vaccination recommended for all persons age 6 months
- Two vaccines currently available (Tables 1 and 2)
- Trivalent influenza vaccine (TIV)
product approved for use in persons age 6 months or older
- Live-attenuated influenza vaccine (LAIV)
product approved for use in healthy people 2–49 years of
- Not indicated for use in pregnant women or immunocompromised
- Administer 48 hours after completion of influenza antiviral
- Administer antiviral therapy 2 weeks after administration
- Specific strains included in vaccine change each year based
on antigenic drift.
- Postexposure prophylaxis
- Antiviral drugs available
for prophylaxis not replacements for annual vaccination (Table 3).
- Consider prophylaxis for persons at high risk of serious illness
and/or complications who:
- Cannot be vaccinated
- Are vaccinated after influenza activity has begun in their
community because development of sufficient antibody titers after
vaccination takes ~2 weeks
- Are unvaccinated and have frequent contact with those at high
- Have an inadequate response to vaccination (e.g., advanced
- Reside in long-term care facility during influenza outbreak
(regardless of vaccination status)
- Are unvaccinated and household contacts of someone diagnosed
Table 1. Approved Influenza
Vaccines for Different Age Groups—United States, 2010–2011 Season |Favorite Table|Download (.pdf)
Table 1. Approved Influenza
Vaccines for Different Age Groups—United States, 2010–2011 Season
|Vaccine||Trade Name||Manufacturer||Dose/Presentation||Thimerosal Mercury Content (mcg Hg/0.5-mL dose)||Age Group||Number of Doses|
|TIV||Fluzone||Sanofi Pasteur||0.25-mL prefilled syringe||0||6–35 mo||1 or 2a|
|0.5-mL prefilled syringe||0||≥36 mo||1 or 2a|
|0.5-mL vial||0||≥36 mo||1 or 2a|
|5-mL multidose vial||25||≥6 mo||1 or 2a|
|TIV||Fluvirin||Novartis Vaccine||0.5-mL prefilled syringe||<1||≥4 yr||1 or 2a|
|5-mL multidose vial||25||≥4 yr||1 or 2a...|