Seasonal Influenza Prevention Update - from JLab's Occupational Medicine Director
Jan. 14, 2013
The purpose of this communication from Dr. Chandler, Jefferson Lab's Occupational Medicine director, is to provide updated information about the lab's seasonal influenza prevention program.
This year's epidemic is from a typical seasonal flu strain. It is not a "novel strain" such as those that have stimulated increased attention in the past.
Your best protection is vaccine (available at the Occupational Medicine department), washing your hands, and using hand sanitizer. (Sanitizing hand wipes may be picked up from Free Stock for use by staff and users to disinfect hands and common-use workplace surfaces, such as phones and keyboards. A new order of liquid hand sanitizer is being made; the lab community will be notified when the order arrives.
This year's epidemic is occurring earlier in the season than is typical. Most years, cases are more sporadic (as opposed to epidemic) until February or so. It's impossible to predict the ultimate intensity and duration this year's epidemic will have. A mild flu year might kill 20K in the U.S. and a severe epidemic might cause 70K U.S. deaths. If one extrapolates this year's experience thus far into the remainder of the flu season, then this could turn out to be one of the 70K-ish years. However, such extrapolation isn't valid, and should be left to vaccine manufacturers and analogous stakeholders.
Prevention of Disease by Vaccination.
* Coverage: There are many strains of flu. Each year the vaccine is formulated against the strains that are predicted to be most prevalent in the upcoming year. This is educated guess work. This year the match is good.
* Vaccine failure: Even with a correct strain-vaccine match, the vaccine does not prevent 100 percent of cases (85 percent is a good effectiveness estimate). If a person receives the vaccine and then becomes ill from a strain in the vaccine, then the illness is usually milder than it would have been without vaccination.
* Availability: There is no vaccine shortage this year. JLab Occupational Medicine has an adequate supply. We began offering vaccine in September and have thus far given 247 doses. If you would like to be vaccinated, please call Occupational Medicine at ext. 7539. Appointments are required, but are often available on short notice.
* Timing: After a person receives the flu vaccine, it might take two or more weeks for full protection to develop. Partial protection begins to occur sooner. Therefore, within a given flu epidemic, it's never too late to be vaccinated. If you haven't been vaccinated yet, and have now reconsidered, please proceed even though the epidemic is already in full swing.
* Safety: Seasonal flu vaccine is extremely safe in absolute terms. Better still, the risk/benefit is highly favorable. The primary reasons to avoid flu vaccine would be significant egg allergy and/or a significant adverse response to flu vaccine in the past.
Prevention of Contagion via Fomites.
Seasonal flu virus lives approximately 8 hours on fomites (inanimate objects such as desks) and can be transmitted via that route.
In order to minimize fomite transmission:
* Wash your hands as frequently as you can, using proper technique. Proper technique involves wetting the hands thoroughly, then using sufficient soap and friction to create sudsing on all surfaces for 20-30 seconds, then thorough rinsing of all surfaces. Such technique is rarely followed.
For flu prevention, antibacterial soaps offer no advantage over other soaps. One reason is that flu is caused by a virus, not a bacteria. (Antiviral soaps are specialty items that have several downsides.)
* Use ethanol based hand sanitizers frequently. Properly used, these kill all bacteria and viruses on contact. Proper use of hand sanitizers involves use of a quantity sufficient to create a liquid film on all surfaces, then allowing the film to air dry. Nooks and crannies under and around nails are easy to miss.
* Train yourself to avoid touching your face.
Prevention of Contagion via Droplets.
Droplets are generated by coughing and sneezing. The person who is coughing or sneezing should prevent droplet and fomite transmission by following "cough and sneeze etiquette":
1. Walk away from others.
2. Turn away from others.
3. Cough or sneeze into something that will capture droplets. Examples include tissues and one's own clothing, especially at the elbow, or into the armpit of a jacket.
4. Stay home when you are ill.
Prevention of Contagion via Aerosols.
While there are arguments about the role of aerosols, the vaccine works no matter what the mode of transmission is.