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Foggy Thinking as Inhaled Flu Vaccine Nears FDA Approval

Worst Pills, Best Pills Newsletter article February, 2003

It seemed like a great idea. Perhaps a vaccine that could be administered with a simple sniff in each nostril, rather than a painful jab, could revive languishing flu vaccination rates in people at risk for the complications of influenza (mostly those over 65 and those with underlying heart disease, lung disease or diabetes). But then public health and science came into conflict with profit — and we all know how that all-too-often turns out.

Back in 2001, FLUMIST, an influenza vaccine made...

It seemed like a great idea. Perhaps a vaccine that could be administered with a simple sniff in each nostril, rather than a painful jab, could revive languishing flu vaccination rates in people at risk for the complications of influenza (mostly those over 65 and those with underlying heart disease, lung disease or diabetes). But then public health and science came into conflict with profit — and we all know how that all-too-often turns out.

Back in 2001, FLUMIST, an influenza vaccine made from live rather than killed virus, came before a Food and Drug Administration (FDA) Advisory Committee, seeking approval for use in healthy people aged 1-64 years. But the Committee soon detected hints that the vaccine was causing asthma in young people and requested more information. The vaccine’s sponsor reached deep into its bag of corporate tricks and came up with the notion not of redesigning the vaccine to minimize its asthmatic propensity, but rather of seeking approval only for people 5 years old and above. Sure, FLUMIST’s market would be reduced, but MedImmune’s stockholders would be happy that the vaccine was approved. Besides, everyone knows that doctors often prescribe “off-label” (outside of FDA guidelines) and drug companies’ “detail men” are famous for encouraging such off-label prescribing.

But this created a small scientific problem. The best designed study demonstrating FLUMIST’s effectiveness (because it measured actual decreases in laboratory-proven influenza vaccination) included 1-7 year olds, but now most of that age group was excluded from the new target population. And the study in adults 18-64 only measured clinical disease, rather than the more accepted standard, in which laboratory proof of the presence of influenza virus is required. Moreover, the adult study failed to demonstrate statistical improvement in the main clinical outcome (“any febrile illness”), although it did for many of the secondary outcomes (e.g., “febrile upper respiratory infection”), and included relatively few people over the age of 50. In fact, in an analysis of the 50-64 year olds planned after the study was complete, there was little evidence of vaccine efficacy, even for the secondary outcomes. The studies also showed that, despite investigators’ efforts, many patients with asthma, who were supposed to have been excluded from the trial, slipped through and were vaccinated. This is likely to be even more common in actual clinical practice.

In a complicated vote, the Advisory Committee decided that there was insufficient evidence of vaccine efficacy in 50-64 year olds. The Committee thus in effect recommended approval exclusively for those for whom the Centers for Disease Control and Prevention (CDC, like FDA, a part of the Department of Health and Human Services) does not recommend flu vaccination: healthy people aged 5-50. The vote was also a landmark in that, with the support of the FDA, it permitted approval for a vaccine based on clinical rather than laboratory outcomes (recall that laboratory-confirmed outcomes were available only for the five, six and seven year olds). And a live virus vaccine at that, with concomitant risks of transmission to unvaccinated persons.

Compounding these problems was the FDA’s failure to insist on any studies comparing FLUMIST to the existing killed virus vaccine. So consumers and physicians are left in the lurch, devoid of the data that should have been produced prior to approval and now probably never will be generated.

What You Can Do

If the FDA follows its Advisory Committee’s recommendations, as it usually does, what are consumers to do? We recommend that you stick with the CDC, which is more immune to industry influence than the FDA. (At least the CDC is not dependent upon the industry it regulates for a large portion of its funding.) If you’re over 65, get vaccinated. If you’re between 50 and 64, get vaccinated if you are in a high-risk group. In any event, get vaccinated with the old, proven inactivated flu vaccine, rather than one with so much murky science behind it as FLUMIST. We also do not recommend the use of RELENZA (zanamivir) and TAMIFLU (oseltamivir) in the treatment of influenza. (These products were discussed, respectively, in Worst Pills Best Pills News’s January 2002 and January 2000 issues.)