Flu Shot Doubts

Years ago my wife and I and our two young kids were visiting our families.  The others came down with the flu, and lay about in misery in the hotel room for days.  But I had had a flu shot, and stayed well, which convinced me to get a flu shot every year since.  While I’m generally a med skeptic, I’ve figured we can see at least a few identifiable areas where med seems most worth the cost, including infant care, trauma care, and vaccines.   So even I’m surprised to see just how weak is the case for flu shots.  Brownlee in the Atlantic:

Some top flu researchers are deeply skeptical of both flu vaccines and antivirals. Like the engineers who warned for years about the levees of New Orleans, these experts caution that our defenses may be flawed, and quite possibly useless against a truly lethal flu. …

We think we have the flu anytime we fall ill with an ailment that brings on headache, malaise, fever, coughing, sneezing, and that achy feeling …  but researchers have found that at most half, and perhaps as few as 7 or 8 percent, of such cases are actually caused by an influenza virus in any given year. …

Jackson’s findings showed that outside of flu season, the baseline risk of death among people who did not get vaccinated was approximately 60 percent higher than among those who did. .. [Thus] the healthy-user effect explained the entire benefit that other researchers were attributing to flu vaccine, suggesting that the vaccine itself might not reduce mortality at all.

The results were also so unexpected that many experts simply refused to believe them. Jackson’s papers were turned down for publication in the top-ranked medical journals. … When the papers were finally published in 2006, … they were largely ignored by doctors and public-health officials. …

The history of flu vaccination suggests other reasons to doubt claims that it dramatically reduces mortality. In 2004, for example, vaccine production fell behind, causing a 40 percent drop in immunization rates. Yet mortality did not rise. In addition, vaccine “mismatches” occurred in 1968 and 1997: in both years, the vaccine that had been produced in the summer protected against one set of viruses, but come winter, a different set was circulating. In effect, nobody was vaccinated. Yet death rates from all causes, including flu and the various illnesses it can exacerbate, did not budge. …

Rising rates of vaccination of the elderly over the past two decades have not coincided with a lower overall mortality rate. In 1989, only 15 percent of people over age 65 in the U.S. and Canada were vaccinated against flu. Today, more than 65 percent are immunized. Yet death rates among the elderly during flu season have increased rather than decreased. ….

Jefferson … [has] combed through hundreds of flu-vaccine studies. … Only four studies were properly designed to pin down the effectiveness of flu vaccine, he says, and two of those showed that it might be effective in certain groups of patients, such as school-age children with no underlying health issues like asthma. The other two showed equivocal results or no benefit. …

In the flu-vaccine world, Jefferson’s call for placebo-controlled studies is considered so radical that even some of his fellow skeptics oppose it. … Everybody … feel[s] strongly that vaccine has been shown to be effective and that a sham vaccine would put test subjects at unnecessary risk of getting a serious case of the flu. …

[But] the annals of medicine are littered with treatments and tests that became medical doctrine on the slimmest of evidence, and were then declared sacrosanct and beyond scientific investigation. In the 1980s and ’90s, for example, cancer specialists were convinced that high-dose chemotherapy followed by a bone-marrow transplant was the best hope for women with advanced breast cancer, and many refused to enroll their patients in randomized clinical trials that were designed to test transplants against the standard—and far less toxic—therapy. The trials, they said, were unethical, because they knew transplants worked. When the studies were concluded, in 1999 and 2000, it turned out that bone-marrow transplants were killing patients.

Another recent example involves drugs related to the analgesic lidocaine. In the 1970s, doctors noticed that the drugs seemed to make the heart beat rhythmically, and they began prescribing them to patients suffering from irregular heartbeats, assuming that restoring a proper rhythm would reduce the patient’s risk of dying. Prominent cardiologists for years opposed clinical trials of the drugs, saying it would be medical malpractice to withhold them from patients in a control group. The drugs were widely used for two decades, until a government-sponsored study showed in 1989 that patients who were prescribed the medicine were three and a half times as likely to die as those given a placebo. …

As it stands, more than 50 percent of health-care workers say they do not intend to get vaccinated for swine flu and don’t routinely get their shots for seasonal flu, in part because many of them doubt the vaccines’ efficacy. … In the U.S. … our reliance on vaccination may have the opposite effect: breeding feelings of invulnerability, and leading some people to ignore simple measures like better-than-normal hygiene, staying away from those who are sick, and staying home when they feel ill.

I’ll join Jackson in calling for randomized placebo-controlled trials of flu shots. More from Jackson:

Seasonal influenza is a relatively rare and benign condition, with an incidence not exceeding 1% in the general population during autumn and winter months.

Hat tip to Carl Shulman.