There’s hopeful news about the possibility of an effective HIV/AIDS vaccine and a weird story from Canada about “preliminary results” saying that you are more at risk from swine flu if you get the seasonal flu vaccine. With flu, anything is possible, but that is more than a little counterintuitive and strikes me as unlikely. Nowhere else has reported a similar experience. Since we don’t know the methods or the data or the limitations or much of anything else that could allow us to consider how much to weigh this as evidence I won’t say any more about it.
While we do write about vaccines here because it’s a topic in the flu world, vaccines are not one of our obsessions. We’d much rather see the hopes and efforts of managing the consequences of an influenza pandemic invested in public health’s infrastructure, not redundant efforts to make a buck on a single target vaccine by multiple companies. Influenza vaccine is a public good and should not be in the market system. But that’s another topic. Since all kinds of vaccines are the topic du jour, we will, for a change, muse a bit about vaccines ourselves. Because some of what we say might be interpreted as mixed or ambivalent and seized upon by a growing movement of poorly informed or misinformed anti-vaccination zealots, we should be clear at the outset about our convictions: we believe strongly that all children should be vaccinated against childhood diseases with the currently available recommended vaccines and that most adults should also be vaccinated with the currently available recommended vaccines. We believe this because it’s the most rational choice given the evidence we have. I also believe it should be essentially mandatory for children and almost never mandatory for competent adults. We’ll discuss the one exception we currently see, shortly.
While influenza vaccination prompted this post, we really want to talk about vaccines more generally because they present some interesting questions. To avoid getting into some hotly debated (although not, usually rationally debated) issues, we are going to make two assumptions which we consider have sufficient scientific support. First, that the currently recommended vaccines are acceptably safe (virtually no pharmaceutical is guaranteed perfectly safe), and whatever risks might exist are unequivocally overwhelmed by the benefits. And second, the implicit corollary of the first that the vaccines work. If you can’t show a vaccine works or it barely works, then you shouldn’t get it. We believe the currently recommended vaccines work, but if you don’t, then you needn’t read further. Still, even accepting these premises, it doesn’t mean there’s no more to say about safety and efficacy.
Let’s talk first about testing the safety of a vaccine for a rare adverse event. You can’t. If you have an event that strikes one in a hundred thousand, no clinical trial imaginable will be able to find it. If it’s so rare, why care? Because when you are vaccinating hundreds of millions of people, rare events pile up. So you are reduced to counting up that pile, which as far as we know, is not negligible but miniscule compared to the pile of people whose lives were saved or whose disabilities were prevented by the vaccine. If the swine flu virus of 1976 had gotten out of Fort Dix and caused a pandemic like H1N1 already has, we wouldn’t ever have worried about Guillain Barre or other rare events. But you can’t know the extent of a rare adverse event, if one exists, until after you use the vaccine in the population. It becomes a problem in post-deployment surveillance.
The rare event problem is true of any pharmaceutical, or for that matter, any mass consumer product. Vaccines, however, are different on two counts. One is the huge number of people they are designed for. Still, there are lots of drugs, especially over the counter drugs, taken by as many people. Yet vaccines are almost unique in that they are being given to people who are healthy. They are not making sick people well. And the rare unlucky person who wins the (bad) adverse reaction lottery is plausibly someone might not have gotten sick in the first place. So it’s not like the adverse reaction to an antibiotic or a cancer drug. And some vaccines — and flu is an example — don’t have 100% efficacy and are designed to prevent a disease that for many people (mistakenly) don’t consider serious and they further believe, for whatever reasons, they’ll never get it. These are psychological problems, not rational risk benefit decisions. It’s hard to think of any vaccine whose risk benefit balance isn’t strongly in favor of the benefit. But it’s clear that it affects how people think.
And maybe that’s OK. I don’t believe in mandatory vaccination for competent adults because I believe in the principle of personal autonomy. Children, who are not considered legally competent to make their own decisions, should have required vaccinations for the many diseases that killed and maimed them in the days before vaccination. I was a teen before there was a polio vaccine. I remember the horror of those days. Measles has almost disappeared and with it many infant deaths from that cause. The same for diphtheria, pertussis and mumps. And forget tetanus. There is nothing unusual about requiring vaccination for children. They are not permitted to do many things and are mandatorily required to do others (e.g., they have to go to school, they can’t vote). There are provisions made for specified exceptions, as there should always be. But if an adult doesn’t wish to be protected, I may think it’s foolish but it’s their choice. The one currently topical exception I lean toward is mandatory influenza vaccination for health care workers. My reasoning is that an infected health care worker comes in contact with people who are at greatly increased risk whom they may endanger by their choice not to get vaccinated. If they won’t be vaccinated, they shouldn’t be allowed to come to work in a health care setting. I work in a health care institution. I know this is controversial with health care workers and their unions. I am strongly pro union and pro worker. But I consider this a special case.
We are not particularly happy that the media coverage and discussion in the public square has focussed so strongly on the availability of a vaccine. It is, as we once remarked, planning for the best (an effective vaccine available in time to everyone) while hoping the worst doesn’t happen. That’s backwards from the way disaster planning is supposed to work (plan for the worst, hope for the best). But that’s the way it’s coming down, so we decided not to ignore it. It’s a difficult issue that’s not completely black and white. We’ll keep our eye on the science and do our best to act rationally.
Difficult or not, a decision has to be made one way or another. We’ve already gotten the pneumovax vaccine for pneumococcal pneumonia and the current seasonal flu vaccine (not mention the shingles vaccine). When our turn comes for the swine flu vaccine we’ll get that, too. We’ll do it for ourselves, for our family, friends and co-workers, and for our community. A public health hat trick. You can’t beat that.