More On Flu Shots
Last week I was asked to give a lecture to the Cardiology Department at Emory and since I had been having an online schermish about the topic I offered “Why I Am Not Getting a Flu Shot This Year“. Well, flu shots are mandated for Emory Healthcare employees so I guess that raised some eyebrows, and I got a call at home asking why I wanted to give a talk about that. After some back and forth I said that I would be willing to give up half of my time, and infectious disease expert James Steinberg MD arrived at the lecture. I presented the fact that randomized controlled trials (RCTs) did not show that flu shots reduced time lost at work or mortality, and that the conclusion of the Cochrane Review is that the evidence does not fit with public health policy when it comes to flu shots, as I have written about before. The one group that might benefit from flu shots according to the Cochrane Review is elderly living in nursing homes, although that may due to the ‘frailty bias’ i.e. some are too infirm to get a shot. A recent study in Lancet of the elderly showed that there was a 40% reduction in pneumonia in vaccinated patients that occured during a time when they could not possibly get the flu; it was mostly due to the bias related to functional status. The actual reduction in flu related pneumonia during the peak flu season was only 4%!
He countered with a study showing that they reduced mortality in cardiac patients (he actually presented only one of two, and the combined evidence is negative, as an article in last month’s Lancet shows). He also showed cohort studies, which are prone to bias.
Finally he showed some studies on vaccination of health care workers showing a reduction in mortality of patients when healthcare workers (HCWs) were immunized. I didn’t think we were talking about HCWs, but I guess that is the reason they showed up. We had some discussions about the utility of immunizing all HCWs, even those not around sick patients, so I thought I would research the topic some more.
It turns out that (surprise, surprise) the evidence for the efficacy of flu shots in HCWs is not that great. The only positive studies are in HCWs who are working with the elderly in nursing homes. And even in that group it looks like both HCWs and the patients need to have flu shots. In fact the Cochrane Review concluded that there wasn’t sufficient evidence to conclude that giving flu shots to HCWs was benificial in reducing mortality in their patients.
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By Amy Philo, September 30, 2009 @ 12:34 am
I bet they are sorry that they even asked you to give up half your time now. Add some fuel to your fire…
By henry, October 10, 2009 @ 2:19 pm
There is an underlying assumption in much of the postings about both the HPV and the H1N1 vaccines that we are dealing with a homogeneous population. We forget that there are large numbers of disenfranchised Americans without access to “routine” health care (like pap smears). There are also large numbers of Americans who live in poverty and crowded living conditions. If one looks at the data from the H1N1 outbreak in Boston, an unsurprising finding leaps out. In large cities such as Boston, the poorer black and Hispanic communities have a much higher morbidity and mortality than average. Likewise, here in Washington State, we have seen a very high rate of severe illness from H1N1 among the native American population living on reservations. Among the pediatric population, we also see a disproportionate effect on children with chronic heart and lung problems and with neuromuscular conditions. Finally, there is a higher risk to pregnant women. While I do not endorse mandatory vaccination for all, I think it is very much a case of throwing out the baby with the bathwater to condemn these vaccines out of hand. It is one thing to disagree with the marketing and profiteering that has become the American way, quite another to disavow any benefits from the vaccines. After all, there is a reason that our infant mortality rate approaches that of a third world country.
The latest statistics coming in from the US H1N1 pandemic show that young children are indeed very susceptible severe infections with H1N1. The number of children requiring intensive care and ventilator support is higher than with the seasonal flu. Most areas of the country are already stressed for pediatric intensive care beds during the peak RSV season. With the added burden of H1N1 acute respiratory distress syndrome, we are very likely to see a shortage of intensive care beds for children, at least on a regional basis. While it may be true that the vaccine may have little to offer healthy adults, there is great potential for harm in making blanket recommendations against the H1N1 vaccine. People with young infants, people living with pregnant women, people caring for children with chronic debilitating health conditions are all candidates for H1N1 vaccination. Unlike nursing homes, these high risk individuals often have limited contact with potential carriers of the virus and thus might well benefit from immunization of their close contacts.