First a caveat, you can fill volumes with what I don't know about avian flu. What I do have a good sense about is the public health system.
The way I see it, there are essentially four processes at work simultaneously that will impact our ability to handle a major avian flu outbreak;
- our surveillance and response capabilities,
- our ability to develop a vaccine
- medical treatment of disease with anti-virals and other therapies which I admittedly know almost nothing about other than Tamiflu is better than nothing; and
- public infrastructure preparedness
People tend to conflate the four processes, which causes confusion and lack of clarity in the way we address problems in dealing with each chain of events. In this diary, I am going to write a little bit about the first two processes simply because I know something about them. Others should feel free to fill in the blanks on issues I've missed.
Ok, to the stuff I actually know something about. Vaccine production follows essentially these steps.
1. Isolate viral strain
2. Convert strain to vaccine
3. Mass produce vaccine
4. Distribute vaccine to public health responders
5. Get vaccine into patient arms
There is a lot we can say about this chain that's interesting--what vaccine technology will be used, which distributors will we work with, who will control distribution, how will vaccine get out to communities, who are the priority populations to vaccinate--but more importantly, I think those are the links of the chain that are important to focus energies on if our strategy is to respond with vaccine. I think at least some lessons can be garnered from our experiences with the vaccine shortage last year.
- Shortages will be inevitable,
- at the start there will be issues of getting existing vaccine to the right places,
- there will be struggles for "control" at the top of government no matter what structures are put in place beforehand,
- communities will take different approaches to rationing vaccine,
- the private sector will be more or less eager to hand over responsibility to manage doses of vaccine to the government in a time of crises (despite what they say before hand to the contrary),
- and eventually vaccine will get generally equitably distributed, but it will take a while
Some of these trends can be expected to repeat in the case of a pandemic and others not. For example, if vaccine gets shipped through State Capitals, and there is a fast-moving, fatal strain of virus moving around, its unclear to me that vaccine will get redistributed out of the capital cities to the local health departments. Its also unclear to me that vaccine will get to the "right arms"--most importantly children first given the epidemiology of how flu spreads, etc. In terms of "preparation" there seem to be a lot of issues on this train to address.
To me, the more realistic opportunity for containment lies in surveillance, early detection, and quarantine and isolation. Essentially, the chain for that process goes something like this.
1. Virus goes wild (i.e. aerosol transmission)
2. Cases are detected
3. Public health response is mobilized
4. Community is isolated
5. Community contacts are traced and isolated
6. Prophylactic treatment (Tamiflu, vaccine) is distributed
(4,5, and 6 occur simultaneously. 6 of course depends on the vaccine supply chain outlined above)
As with the first chain, there is a lot to chew on here, some of which we have experience with and some of which we don't. For example, from SARS, we know that some governments move faster than others to deal with emerging infections and countries have different levels of tolerance for international intervention resulting in isolation and quarantine of their citizens. Ultimately, it's troubling for me as a liberal because the things likely to be most effective against flu--police state lockdowns--are the things I distrust most about government.
There are things on this chain that we can do more to prepare for. For example, its unclear that US laws provide for public health to conduct mass quarantines and isolation, there is little coordination between government regarding how to handle global air traffic, and of course different countries have very different surveillance and detection capabilities. While we may spend millions to develop computer algorithms to detect outbreaks in passively collected surveillance data (so-called syndromic surveillance), countries in the third world scarcely have a system for doctors to report strange cases to the health department. We know that hemorrhagic outbreaks of Dengue and Ebola often go undetected for weeks in the third world, so what about flu in areas where fever, pneumonia, and respiratory death are common place? Is it realistic to assume that our sophisticated surveillance systems at home can help us prevent introduction from the Third World? Maybe, maybe not - depends on our capacity to act decisively and our willingness to quickly abridge the civil rights of ourselves and others immediately and without debate.
We haven't even raised these issues as a society yet. Ironically having a weakened president (which benefits us greatly in many other ways) puts us at huge risk when it comes to flu.
The two other chains of flu preparedness are also important and are related to each other. Medical treatment could dramatically lower mortality from flu (few people are worried about morbidity), if medical facilities can stay operational. Staying operational depends on a good plan to maintain order during a crises, to manage a huge surge in healthcare demand, to communicate with a justifiably frightened (panicked?) population., and to replace personnel who are themselves sick and/or dead.
Others like the idea of infrastructure preparedness plans ahead of the flu. Don't get me wrong, planning is better than not planning I suppose. The problem is that we are not very good at handling surge in health care demand with full staff. The 1995 heat waves in Chicago shows that a surge of only about 10% above normal maximum capacity can swamp emergency rooms to the point of shutdown. Pandemic flu presents a case where health care demand could be 100 to 500% above normal peak capacity, and it will happen at the same time as staff itself will be operating at below capacity.
Apply this function to all essential services, police, fire, etc, and its hard not to get pessimistic about our ability to manage a pandemic once its spreading.
Therefore our big hope is currently to identify the infection early and stop it before it spreads.
Finally, its important to concede the mystery of all this. We plan for things that are within our imagination. We know about the 1918 pandemic, so we plan for that. But a new pandemic could be much milder or much more deadly than the 1918 flu. We just don't know. The dynamics of viral spread depend on its infectivity, the rate at which it incapacitates/kills. Ironically, a more deadly flu is harder to spread because those in a position to spread it are too sick to make contact with people.