Part I recap: Modern health care has made us secure in many ways, but we live in an era not so long removed from a time when disease could wipe out a family, a city or a civilization. What we know of epidemics now mostly comes from the history books, and even that is simply a table of numbers and dates. Part 1 of this three-part series reviewed the clinical facts about smallpox, the history of vaccination against smallpox and the push by President Bush since 9/11 and the unrelated anthrax attacks to immunize millions of health-care providers. The article also introduced the cardiac side effects of vaccination that had not been noted during previous widescale smallpox vaccinations.
Like any medical procedure, there are certain risks associated with the use of the smallpox vaccine. Large-scale studies in the 1960s and 1970s revealed that mild reactions occur in up to 30% of recipients and include local pain, erythema, adenopathy, myalgias and fatigue. More serious reactions were fortunately rare. More recent work with the first crop of post 9/11 vacinees paints a somewhat different picture. Critically, there were 27 probable or confirmed cases of myopericarditis in the military group, five cases of cardiac ischemic events in the civilian group and two civilian deaths from myocardial infarction associated with the smallpox vaccine.
It's my sense that much of the difference in the type and incidence of side effects from immunization has to do with the patient population. Instead of immunizing otherwise healthy children (including some who may have already developed a degree of immunity to the disease), we're now giving the vaccine to large groups of adults. Advances in health care have meant that there are relatively more people in our society with pre-existing chronic medical conditions. Our clinical tools are better as well, allowing us to study reactions that before would have been termed idiosyncratic (there's a cocktail party word for you). A reflection of our advancing knowledge of cardiac risks factors underlies the current advice that smallpox vaccination be withheld in routine circumstances from those with three or more of the risk factors of hypertension, hypercholesterolemia, diabetes, cigarette smoking, or a family member with heart disease, regardless if the vaccine recipient himself has any heart problems.
The complication rate of the smallpox vaccine may be a clinical reason why people are not complying with the government's wishes for immunization. Although the rate of complications is low, the media certainly magnifies the risk. It's not their fault; it's their job to make people aware. It's ours to put these reports in perspective, both in the media and our own efforts in patient care.
The vaccination process itself may be a disincentive. Rather than a single shot (such as the influenza vaccine) or a swallow of liquid (as with the oral polio immunization), vaccination against smallpox requires multiple needle scrapes into the deeper dermal tissues. The vaccination leaves a blister that will rupture and leak infected fluid, requiring covering of the wounds. The scab overlying the blister falls of within two weeks. While the blister and scab are present, care must be taken to not expose others to the vesicle, fluids or any wound dressings or materials due to the risk of inadvertent contact with the live virus. (Again, I'll take the liberty of referring you to the U.S. Centers for Disease Control and Prevention (CDC) Smallpox Home Page at http://www.bt.cdc.gov/agent/smallpox/index.asp for more detailed discussions of the risks and benefits of the vaccine).
There are a host of logistical issues that may also affect the acceptance of the program.
While most Health Departments are more than willing to take the vaccine to the worksite, the vaccine cannot be found in physician's offices or other common points of care. The possibility of transmission of the live vaccinia virus by contact means that hard choices must be made in allowing heath-care providers who have just been vaccinated to continue their participation in hands-on patient care until the vaccination lesions fully heal (the literature does indicate that this should not be a problem given an appropriate wound dressing and careful hygiene).
There are major questions of liability for the complications of the vaccine, especially when the employer requires vaccination (as I write this, I have just received notice that the federal government has established a Smallpox Vaccine Injury Compensation Program). Legal issues also spill over into such mundane things as paperwork. In our Health Department, the standardized State of Florida Smallpox Immunization Consent Form runs to 25 pages. This is actually an improvement; an earlier form contained nearly 40. By way of contrast, the consent for the influenza shot is a single sheet of paper. No matter how motivated you may be to get the smallpox vaccine, 25 pages of warnings, cautions and hazards are bound to steer you away from the idea.
There's one other clinical point to keep in mind. If a case of smallpox is discovered, will you be able to get the vaccine and still be protected? Guidelines from the CDC suggest that the primary response to an identified case of smallpox is to isolate the patient and vaccinate those persons most likely to come into contact with the case. This process is called "ring vaccination," reflecting the idea that we vaccinate those around the patient to form a barrier to the rest of society. If one requires emergency vaccination, inoculation within three days of exposure may prevent (or significantly decrease the severity of) a smallpox episode. Vaccination four to seven days after exposure offers some, but less, protection than an immediate dose of vaccinia.
So it seems that once the initial case of smallpox has been identified, you still have time to become protected through immunization. Given that the CDC defines a single case of smallpox in the United States as a public health emergency, it would seem reasonable to assume that vaccine would be readily available to all who needed it. The danger is that if you happen to be that initial case, you're simply out of luck. But to some extent, most of us make decisions based on "playing the odds." We make our plans each day knowing that we could cross the street that morning and get whacked by a beer truck. But because the odds are against it, we don't perceive an imminent threat. Short of taking common-sense precautions that pose no risk or discomfort to ourselves, we ignore the risk. In all honesty, I think that's what's behind the lack of enthusiasm for the smallpox vaccine. It's the perception of personal risk or the lack of it.
(Speaking of playing the odds, I had an interesting conversation with some employees here at the Health Department about the Florida Lottery. We were mentioning that we've all heard of people who say that if they won, their lifestyle wouldn't change. I just want to state publicly, on the record, for the world to see, that if I win the lottery my lifestyle will absolutely and irrevocably change overnight. For example, I am convinced that the Volusia County Health Department needs it's own aircraft. Perhaps a small Lear jet or maybe a Cessna Citation. We'll use it for community surveillance, for spotting microbial disease from the air. Yeah, that's the ticket.)
The idea of personal risk is at the heart of another article in the same issue of Annals of Emergency Medicine. Titled, "The Risks and Benefits of Smallpox Vaccination: Where You Stand Depends on Where You Sit," it offers a fascinating look into the psychology of the potential vaccine recipient (that's you and me). The authors consider that the decision to vaccinate is based on an individual's answer to three key questions:
- What is the risk of a smallpox incident?
- What is the risk of being exposed to an unrecognized case of smallpox before mass vaccination begins?
- What are the risks of an adverse reaction to the vaccine?
These three questions frame the decision. If the risk of a smallpox release and exposure were high and the risk of immunization were low, then people would be willing to get to vaccine. But if the perception is that smallpox release and exposure are low-risk events and complications are common, then people would understandably shy away from the vaccine. You can think of this decision process like the cut on the Meat Loaf "Bat out of Hell" album. Two out of Three Ain't Bad.
The analysis is so simple it's brilliant. The decision to be vaccinated against smallpox has nothing to do with national security, fundamental cultural differences or any other factor outside of ourselves. In truth, "it's all about me." (One of my favorite philosophical tales concerns the concept of solipsism, or the belief that there is only one mind in the universe and it's your own. This prompted one philosopher to write to another, "I really enjoy solipsism. You must try it sometime.")
This seems to be where the government erred in their expectations for the smallpox program. It was assumed that people shared the government's vision and had the same certainty as did policymakers of the chance of bioterror. We can argue about why the vision was not shared (a lack of actual attacks, a "numbing" of the population under continual warnings, the fact that no bioterror weapons of mass destruction have been found). Nonetheless, the government assured itself that people would volunteer to put themselves at risk for the public good. For whatever reason, that simply has not turned out to be the case.To be concluded next week ...