Pandemic influenza, or “Pan Flu,” differs from the “regular” flu in a number of substantial ways. To understand them it is important first to understand what the flu is – namely, an infectious disease that is caused by a virus.
In the simplest terms, viruses are strands of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), the blueprints that cells use to reproduce. When the virus infects healthy living cells it plugs its own DNA into the cellular machinery of reproduction and tricks the invaded cells into creating more viruses.
For the person infected with influenza the results can range from mild “flu-like” symptoms such as body ache, fever, headache, tiredness, sore throat, runny nose, and cough – lasting a week to ten days, or so – through a fatal pneumonia. Hundreds of thousands of people die each year from the flu – including, according to the U.S. Centers for Disease Control and Prevention (CDC), an estimated 36,000 in the United States.
Control Measures and the Drift-and-Shift Effects
The main method for protecting oneself from influenza is to be vaccinated every year. There are both an injection version and a spray version of the vaccine in use in the United States. Every virus has proteins on its outer surface that are unique to that viral strain. When a person encounters these proteins it “takes an image” of them and stores it within his or her immune system.
Later, when the person encounters other proteins, that person’s immune system checks them against the stored images. If a match is found, the immune system can deal fairly quickly with the virus. A vaccine works by introducing just enough material into the body to trick the immune system into forming images that will help identify the complete virus.
The influenza virus is not a static creature. Central to understanding why annual vaccinations are needed is a factor called genetic drift and shift. Each time a virus reproduces itself there is the possibility of a mistake. When enough small mistakes accumulate, these errors result in a virus that no longer matches the old image, so the immune system sees it as something novel. This process, which is called drift, may take six months or more to become different enough to evade even vaccinated immune systems.
When two viruses encounter one another they sometimes exchange pieces of their genetic material, and each comes away as something distinctly different from the original. This process, called shift, allows for rapid major changes in the virus in a single event. The exchange is often significant enough to transfer characteristics from one virus to the other.
Of major concern is that a flu virus such as H5N1 (the designation given to the avian flu) that is lethal to humans but hard to pass from person to person will exchange material with a virus that is relatively easy to pass from person to person. If this shift occurs, the resulting virus not only may cause a high mortality rate but also be person-to-person transmissible – and thus would be a likely candidate for causing the next pandemic influenza.
Regardless of the process, shift or drift, that creates a new virus, current immunity to the original might not be effective against the new virus. In other words, last year’s flu shot probably would not be effective against this year’s flu.
There are other defenses against influenza. Anti-viral medication can be administered. From the patient’s perspective these are somewhat similar to antibiotics: One pill one or more times a day helps the body fight off the infection. Unfortunately, there are not enough of these medications available to treat all probable cases of the flu in the United States (and the shortages are worse in almost all other countries). Moreover, viruses repeatedly exposed to these medications may become resistant to them, rendering the antiviral less effective.
Good basic hygiene and good manners both play a large role in controlling the spread of influenza. Washing one’s hands and covering one’s mouth when coughing will significantly slow the spread of the flu. Alcohol-based waterless hand-washing liquids also can help, particularly in situations that do not allow for frequent hand washing.
The Emergency Planning Issues Involved
Pandemic influenza presents some specific, and major, problems for medical professionals involved in emergency planning and/or with vaccine production and delivery. There is no way to stockpile the vaccine, because the vaccine stored away this year will probably be no longer effective next year. However, the stockpiling of anti-viral medications is possible.
Last year’s vaccine shortage in the United States provides a good model to use in estimating the possible effects on the vaccine supply at the start of a pandemic. The British manufacturer of vaccine, Chiron Corporation, was unable to bring its product to market. It was more than just a lost batch of vaccine; Chiron’s operation was shut down for the season. The company’s production capacity was thus removed from the total worldwide capacity. But there is very little excess worldwide capacity available at any time; as a result, even with a full-capacity effort by other manufacturers, shortages ensued.
Vaccine production during an influenza pandemic can be expected to exhibit a similar gap – of much greater magnitude, though – between capacity and demand. During the initial phase of pandemic influenza there probably will be little or no effective vaccine available. Because the normal time lag between vaccine development and production is about six months, this means that there will undoubtedly be major shortages – resulting more from the increase in demand than the decrease in supply – during the first year of a new pandemic. An even worse problem, perhaps, is that, because of shift and drift, the vaccine developed during year one may be ineffective during year two and so on.
Question: Who Will Be Saved?
One of the major issues facing state and local public health officials is determining who or what categories of citizens must or should receive the first doses of the vaccine. There are two schools of thought on this issue. The first places highest priority on the risk imperative, as presented by the CDC recommendations for annual flu vaccinations, which holds that those persons considered to be at an increased risk should be vaccinated on a priority basis. The second school adheres to what is called the functional imperative, as outlined in the World Health Organization (WHO) Guidelines on the Use of Vaccines and Antiviral during Influenza Pandemic, which holds that those who are essential to the safety and basic functioning of the community should be the first persons vaccinated.
A good example for discussion are those in the medical community who would care for the ill. These people should be protected not only because of the increased risk they face from their continuous work exposure but also because of the essential role they play in saving the lives of others.
During a supply crisis one of the most important task facing decision makers will be to prioritize groups needing vaccination on a priority basis. Doctors and nurses working at hospitals are an obvious first choice. Less obvious are all other hospital workers: the technicians who provide respiratory care, for example; the doctors who are now administrators, primarily, and no longer see patients; the housekeepers without whom patients’ rooms never get cleaned and therefore become unusable (because proper hygiene is a mainstay of flu prevention). The litany of groups with varying claims to priority status is, in short, a very long one.
Even if high priority is given to the entire hospital staff, difficult triage-type decisions must still be faced. Many medical people do not work in hospitals, for example. Nor do the first responders in the community – firemen and policemen as well as EMS (emergency medical services) workers who play an essential role in times of crisis. Truck drivers, railroad engineers, and the officers and crews of ships who transport the food, energy supplies, and other necessities of life – and keep the nation’s economy on an even keel – all could justifiably lay claim to the title of “essential worker.”
Unfortunately, there simply will not be enough vaccine and/or other medications to protect all of these groups. In fact, a decision that priority be given to the entire staff of hospitals may require more vaccine than is likely to be initially available.
According to a Government Accountability Office (GAO) report, 15-37 percent of the population is likely to be affected at any given time during the pandemic. The CDC estimates that 5-20 percent of the population would be ill at any time. The difference between these seemingly conflicting estimates is that the CDC estimate includes those who are actually ill, whereas the GAO estimate also includes both those who, because they are concerned about being infected, choose not to come to work, as well as those who are staying at home to take care of a sick relative. For practical purposes, it seems reasonable to use a 15-percent average to represent the number of people staying home for all of these and perhaps other reasons.
By canceling elective procedures and taking other short-term steps a hospital may be able to operate without 15 percent (or perhaps slightly more) of its staff. The history of previous influenza pandemics suggests, though, that a future pandemic may well continue for at least several years – beyond the effectiveness of these short-term solutions. Moreover, hospitals and other medical facilities will have an extra burden to carry if 15 percent of their own service populations are seeking medical care for the flu (more, if there are large numbers of what are described as the “worried well”).
Also contentious is the issue of how to prioritize under the imperative of risk. The priority could be assigned by age, giving babies from six months to two years or so the highest priority because their immune systems are not up to the challenge of fighting off the virus; another option is to give the old and infirm high priority because their immune systems have become weak.
The Right Answers Are Not Always Fair
Coming up with the “right answers” – however that term is defined – will not be easy. During the first days of a pandemic there simply will not be enough vaccine to cover all of those in the priority groups, much less all others who, fairly or unfairly, are in lower-priority categories.
If and when an effective vaccine is available in sufficient quantity, moreover, it will be a daunting challenge to inoculate the entire population. Annual flu vaccination clinics cannot be looked at as the solution for dispensing the pan flu vaccine. “Routine” clinics conducted by public health officials and the medical communities differ significantly, in two critical ways – the first is volume; the second is security – from those needed to respond to a pan-flu outbreak.
Annual flu clinics inoculate about half of the population; numerically, therefore, the complete inoculation of the population required in a pan-flu crisis would require the capacity of twice as many clinics. But with the estimated non-availability of 15 percent of those needed to operate existing clinics this may not be possible.
A better model to consider, perhaps, may be the local POD (points of distribution) plans developed for use under the Strategic National Stockpile (SNS) program. In the event of a pandemic flu that is killing people in large numbers it can be anticipated that when there is not enough vaccine available there well may be violent encounters when and where the vaccine is believed to be. One result is that, to maintain order, even those clinics without vaccine probably will need a law-enforcement presence, a requirement that would undoubtedly put another strain on the community.
It seems obvious that decision makers at all levels of government – federal, state, and local – must develop the mindset that Pandemic Influenza represents as significant a public-health emergency as a smallpox attack by a terrorist, and then let that mindset guide their planning. The only substantive difference between these two extremely different crisis scenarios is that even the most rigorous actions and investigations by law-enforcement personnel cannot stop pandemic influenza.
Too Much To Do, And Not Enough Time
In short, time is on the side of the virus. It normally takes about six months to bring a vaccine to market. That time may be shortened somewhat by hard work and the cutting of bureaucratic red tape, but it is almost certain that major improvements in speed would be impossible.
Pandemic influenza can start at any time, independent of what is believed to be the flu “season,” and it runs its course over the span of years, not just one year. Once a pandemic strain of influenza starts to roll, moreover, it will affect a certain percentage of the population constantly for a number of years. This means that at any time during a pandemic the same estimated 15 percent of the population will not be going to work. The net effect will be that every government agency, every component of the public and private infrastructure, and every other business and non-government organization will have to operate with only 63 to 85 percent of their current work forces available – management and technical experts included – and few if any replacement workers on call as substitutes.
Dealing with a pan-flu outbreak will require exploration of the extremes of continuity both of operations and of government planning. Every agency, organization, and business should for that reason develop what might be described as an “Armageddon” plan – i.e., one that deals with the total loss of all resources. Systematically, planners should go through the normal operations of the organization and ask at least three questions: (a) “What resources are needed for each task?” (b) “What would be the impact of losing this or that specific resource or function?” (c) “What contingency plan can and should be activated to deal with the loss of each such resource or function?”
It should not be assumed, of course, that all provisions of an Armageddon plan would have to be put into operation at one and the same time. Such a scenario would mean that there had been a total loss of all resources, but at that point no contingency would work because there would be nothing to work with. The purpose in developing an Armageddon plan is that it would be a resource unto itself. Because the response to the loss of each specific resource and/or function would be spelled out in considerable detail, the plan could be activated whenever there is the loss of just one resource or function.
Government also must plan well ahead of the pan-flu time curve, not only for how essential services will continue to be provided, but also for how the legitimate leadership of government will continue. At the federal level there are provisions in place for the orderly transfer of power if the president dies or can no longer function in office (the vice president would be next in succession, then the speaker of the House, and then the president pro tempore of the Senate, and so on). Individual government agencies also should consider either setting up their own orders of succession (under the direction of the president, of course) or face the possibility of being unable to provide their services during future times of crisis. Done properly, these and other forward-looking steps would be equally applicable during any future event that might stress the system.
To summarize: Pandemic in influenza represents a major threat not only to the United States but to all other countries of the world, friends and foes alike. It is for that reason that a projection of the effects of pandemic influenza is one of the national-crisis scenarios that is of continuing concern to contingency planners. Moreover, unlike the various scenarios projecting terrorist attacks of one type or another, there is no law-enforcement solution available that might lower the risk from a pandemic. Continued surveillance, by the U.S. CDC and the World Health Organization, of the H5N1 strain of the u is likely to be the only consistent source of valid intelligence information available to contingency planners and public officials for the foreseeable future.
But that should not stop the governments of all nations – all businesses and other private-sector entities, individual citizens as well – from making their own plans and preparations now while there is still time. Even with the best, most detailed, and most comprehensive planning, though, and the most energetic follow-on effort required, there still may not be enough time to prevent the death of not just millions, but tens of millions of people throughout the world.
Joseph Cahill is the director of medicolegal investigations for the Massachusetts Office of the Chief Medical Examiner. He previously served as exercise and training coordinator for the Massachusetts Department of Public Health and as emergency planner in the Westchester County (N.Y.) Office of Emergency Management. He also served for five years as citywide advanced life support (ALS) coordinator for the FDNY – Bureau of EMS. Before that, he was the department’s Division 6 ALS coordinator, covering the South Bronx and Harlem. He also served on the faculty of the Westchester County Community College’s paramedic program and has been a frequent guest lecturer for the U.S. Secret Service, the FDNY EMS Academy, and Montefiore Hospital.