A STAMARIL Center
John D. Wilson, M.D.
1200 Hilyard St., Ste. 560
Eugene, Oregon 97401 USA
INFLUENZA AND INTERNATIONAL
I will try to outline a reasonable benefit/risk/cost analysis of whether to
give influenza vaccine to international travelers.
Influenza may be transmitted during air travel while crowding in airports and
airplanes. Influenza outbreaks have been documented aboard cruise ships.
Influenza is probably passed (like meningococcal disease or pertussis) by short
range droplet as well as person-to-person contact; crowding of people who
congregate from multiple geographic sites (similar to increased risk for
meningococcal disease in military recruits in barracks and college students in
dorms). Fears about ventilation aboard aircraft are probably exaggerated. I am
less worried about aircraft ventilation than I am about someone coughing within
a few rows of my seat. I also wonder about who touched the doorknob I touch just
before I scratch my nose, and did he wash his hands after he coughed into them.
The CDC recommends influenza vaccine if a person will be mixing with crowds
which may contain international visitors, regardless of the time of year. This
would obviously include any air traveler to a destination outside the US. If you
think about it, influenza is probably the most vaccine-preventable disease a
traveler is likely to contract.
Influenza tends to occur throughout the year (rather than seasonally) in the
tropics, the closer one gets to the equator. We already know about influenza
occurring in the temperate southern hemisphere during their winter (our summer
I make sure my patients, family, staff and myself are all appropriately
immunized against influenza each September or October, even if we are not
traveling, and have been doing so for 25 years.
Domestically, in the US, we have the situation that the vaccine works least well
in the patients who need it most (infants and the elderly and the chronically
ill), and until we can also immunize the people around them, we will likely
continue to have millions of cases each winter, and an estimated 30,000 to
Influenza vaccine is not perfect. It is very safe unless someone is so allergic
to eggs that eggs cannot be eaten. We need a better vaccine and a better way to
make it. For now, it is what we have.