It’s the time of year when all my biomedicine newsletters and other resources start recommending the influenza vaccination. It used to be that infants and the elderly were the primary targets. This year I’m seeing more recommendations that everyone get vaccinated.
I remain skeptical. It’s not that I take a militant anti-vaccine stance in general. But my hubris alarm goes off when I see blanket recommendations for a vaccine (or anything else) with such mixed evidence of usefulness. Unlike polio or smallpox, for example, there is no suggestion that inoculating the entire population will eliminate the disease. In fact, because of mutations and variable prevalence of different strains of flu virus, manufacturers have a hard time predicting which vaccines to produce for the upcoming season. And inoculation is no guarantee you won’t catch the flu, although symptoms should be milder. Overall, the evidence of benefit from vaccines is muddy.
Influenza, and the bacterial pneumonia that may develop following a flu virus infection, can be deadly. The elderly, particularly those with prior respiratory conditions are at particularly high risk. Infants, young children and those with compromised immune systems also have higher mortality risk than others. Unfortunately, most statistics lump the flu and pneumonia mortality rates together, and most flu infections are probably never confirmed by lab tests - patients either don’t go in to see a doctor, or their doctor makes a diagnosis based on clinical observation.
While some studies seem to show a clear benefit from vaccination, others refute those apparent outcomes. For instance, asthmatic children are generally urged to get vaccinated, but a 2005 study of 696 children (aged 6-18 years) that covered the two previous flu seasons “did not find a beneficial effect of vaccination on the number, duration or severity of influenza-related asthma exacerbations.” Studies which have seemed to show a particularly strong benefit from vaccination in the elderly have also been brought into doubt: recent work suggests those results were confounded by the “healthy user effect.” That is, the healthiest, and most health-conscious people were getting the vaccinations in the first place, and thus would be expected to have the least adverse effect from influenza or pneumonia. Perhaps there was benefit from the vaccinations, but not nearly to the degree originally suggested.
Rather than just argue pros and cons of individual studies, I thought it would be interesting to see if there has been a clear change in mortality since flu vaccinations came into more widespread use. This does not look all that convincing, either. A graph compiled from CDC data at www.healthsentinel.com charts the flu vaccination rate against combined mortality rates of flu and pneumonia. It shows no obvious correlation between increased vaccination and lower mortality. There was actually a large decline the mortality rate in the late 1960’s - mid 1970’s before vaccination was prevalent. A recent leveling off of mortality rates could be due to better supportive care or less virulent strains of influenza. In any case, the combined (flu and pneumonia) mortality rate in 2004 was similar to that in 1964, despite the initiation and fairly rapid adoption of vaccines.
Another concern is the possibility of the flu viruses becoming resistant to treatments. After a mild 2006-2007 flu season, the 2007-2008 season was tougher. The Centers for Disease Control and Prevention (CDC) reports that evidence of resistance to the anti-flu drug Tamiflu was observed during that period.
Nonetheless, the CDC maintains that “Annual influenza vaccination remains the best method for preventing influenza infection and its potentially severe complications.” Nor has the CDC made any changes in their recommendations for the use of the Tamiflu class of drugs (neuraminidase inhibitors), although they have instituted closer surveillance of the drug-resistant influenza viruses. CDC has in fact expanded its recommendations for influenza vaccination. They now to include all children from six months through 18 years old, all people with increased risk for influenza complications, adults aged 50 and over, those with suppressed immune systems or other chronic conditions that might put them at higher risk for complications, and those who reside in nursing homes or chronic care facilities, or who will be pregnant during the flu season. They also recommend that people who share a home or come in close contact with those who are at higher risk for influenza infection also be vaccinated. Whew! Apparently 19-49 year old recluses in perfect health don’t need a shot.
So, what to do? As a pharmaceutical minimalist I’m disinclined to recommend putting substances into one’s body without clear benefit. I also worry about the overuse of medications that can lead to drug resistant diseases. We are well down that path with resistant strains of bacteria, yet antibiotics are still commonly overprescribed. One of the justifications for inoculating nearly everybody for influenza is the increased chance of developing an antibiotic-resistant form of pneumonia when weakened by a flu infection. But by giving anti-viral drugs to healthy adults who would likely just have a few days of discomfort from the flu, are we insuring that influenza strains become increasingly drug resistant?
Personally, pending better information, I would be inclined to get an influenza vaccine if only I were in one of the higher-risk population groups. Meanwhile, everybody should be more careful about hand washing (one of the best ways to prevent the spread of disease in general) and covering their mouth when coughing or sneezing. Avoiding close contact with those who are infected is great if you can do it, but a significant number of carriers won’t show symptoms anyway, so that one is tougher to accomplish. And to keep your immune system at its peak, getting a good night sleep, eating well and exercising regularly can help significantly. Oh, and do I have to say it? Stop smoking!
Clinically I see Chinese herbal medications providing a lot of benefit, but mostly if they are used early and aggressively; even a half day procrastination can make a difference for the worse. Most people will only have a day or two of discomfort if they start herbs right away. For early stage cold or flu I like the over-the-counter formulas called Gan Mao Ling combined with Chuan Xin Lian (andrographis). As always, I would recommend caution (meaning consultation with a board certified herbalist and/or your medical doctor) if you are already taking medications or have complicating health issues.