Take The Shot

Swine Flu

Is the so-called Novel Swine Influenza A (H1N1) a fluke? Is it about to disappear from the landscape as another ‘could have been’ red-herring danger like the bird flu that failed to materialize? The answer to these questions is definitely ‘no!’ This disease has been in the headlines practically every day for the last two months. The death toll now (8/27/09) stands at over 1,799. The latest US toll now stands at 522, and you should click on the map for a current tally from the CDC by US state, to obtain the latest mortality statistics, which are going up every day. On June 11th, swine flu was declared a global pandemic by the World Health Organization (WHO). The WHO signaled that a global pandemic of a novel influenza (H1N1) was underway by raising the Worldwide Pandemic Alert Level to Phase 6. This action was a reflection of the spread of the new H1N1 virus, not the severity of illness caused by the virus. At the time, more than 70 countries had reported cases of this infection and there were ongoing community-level outbreaks in multiple parts of the world.

Could swine flu become the equivalent to the 1918 Spanish Flu in which an estimated 500 million people become infected and [50 to 100] million people died worldwide (3 to 6 percent of the world population)? This was arguably the most catastrophic infectious event in human history, which is exhaustively documented in a variety of excellent books. The real answer to this question is "We don’t know." And therefore, we have to be prepared for every contingency; this virus could undergo a mutation that would sharply increase its virulence through human-to-human propagation at any time and not simply through a bird or animal vector.

So what can we and should we do about it? Some in England have become so worried about this flu there are reports that Britons are hosting "swine flu parties" in an attempt to build immunity to the virus. "I don’t think it’s a good idea," said Dr. Richard Jarvis, Chairman of the British Medical Association’s Public Health Committee — and no physician would disagree with him.

Building a stockpile of vaccines against this flu and distributing it to staging areas in preparation makes the most sense. But decisions to produce the vaccine quickly, such as that manufactured by GlaxoSmithKline, has run into problems. This vaccine will only be tested on a limited number of people, as the U.K. drug maker weighs the pandemic’s danger against the risks of an unsafe or ineffective shot. Someday influenza vaccines will be produced synthetically, but for the time being the old fashioned methods of growing the vaccine in chicken eggs is the world standard, and it takes many months to produce an adequate supply. Furthermore, the existing Tamiflu vaccine does not appear to be the answer.

Paris-based Sanofi-Aventis, SA, has its own swine flu vaccine that became available for testing in early August. But it then takes two and a half months of testing before having a shot that’s "both safe and protective," according to Albert Garcia, a spokesman for the company’s vaccine unit. The vaccine will probably be ready in November or December, Garcia said. Baxter has also produced a vaccine in early August, after which it will perform clinical tests, said Chris Bona, a spokesman for the Deerfield, IL, company. Glaxo, meanwhile, said it’s on track to meet government orders for 195 million doses of vaccine and another 50 million-dose donation to the WHO, and the first supplies should be available in September.

Chicken egg vaccineBoth Glaxo and Sanofi said they will be tailoring their tests to meet regulators’ demands. "We’re following a plan which is defined by health authorities," Glaxo CEO Andrew Witty said. Glaxo also said that it’s developing a face mask coated with antivirals to prevent infection and boosting production of its Relenza drug for patients already suffering from swine flu.

The World Health Organization estimates that, by August, global production of the vaccine will reach 94.5 million doses per week. But this estimate relies on all companies using formulations with novel adjuvants — additives to the vaccine that boost the immune response and reduce the amount of virus needed for each dose. However, the adjuvants have not been approved for use in the US. Last week, the US National Biodefense Science Board said that in order to have any vaccine available by September, the US should stick to the well-tested formulation of the seasonal flu vaccine — with 15 micrograms of the main viral protein, hemagglutinin, per dose. The WHO warns though that if adjuvants are not "fully used" the amount of vaccine available per week will fall by [40 – 50] percent.

So who should be at highest priority for getting the vaccine first? US, UK, and other governments have promised that people at greatest risk from the virus will be vaccinated first. But it is not yet known if this means children [6 months to 18 years], pregnant women, caregivers to babies less than six months old, or those who have chronic disease conditions or obesity [25 – 64 years] — so far, all these are the clearest risk factors. Of course, it is generally agreed that first-responders and health-care workers should be among the first to be vaccinated.

The US Government has called for volunteers for the first swine-flu shots in a race to test whether a new vaccine will protect against the virus before its expected rebound in the fall. The first of a pair of shots has gone into the arms of healthy and elderly volunteers during the second week of August (separated by three weeks) in one of eight NIH Study Centers.

Vaccine injection into armFinally, what has all this swine flu stuff got to do with the regular seasonal flu for which most of us get our flu shots every fall? Answer: "Nothing." The FDA has just approved this year’s seasonal flu vaccine, and it is expected to be available at its regular time in early October [22]. That means we should plan on getting two sets of shots this fall as soon as they become available. Another logistical problem is that to achieve full immunization against swine flu, it is expected that two doses (first a regular shot and then a booster shot three to four weeks later) will be necessary. Remember the old adage, "a stitch in time saves nine."

The CDC and Homeland Security needs to make sure that the published rules for priority vaccination are observed throughout the US when this vaccine first becomes available to the public in the middle of October. According to the laws of economics, as soon as we experience a problem of supply-and-demand in which a scarce resource is in extremely high demand, you can be sure that it will create the potential for a black market to indulge the needs of those willing and able to pay more. But this need not happen if the government plans the distribution process equitably. This will also be a challenge for local law enforcement, if persons who were expecting to get their shot by a certain date are disappointed and angry after waiting in line for a long time.

If all this seems a little melodramatic to you, you should read a recently released report by the President’s Council of Advisors on Science and Technology (See Resources). Co-Chaired by John P. Holdren, Eric Lander, and Harold Varmus, the council made a series of strong recommendations based on a set of assumptions in which they pulled no punches:

(a) 30 to 50 percent of the US population will be infected (60 – 120 million Americans), even though not everyone will experience symptoms;

30 to 50 percent of the US population will be infected (60 – 120 million Americans), even though not everyone will experience symptoms

(b) Up to 1.8 million patients will need hospital care (300,000 will require intensive care admissions in heavily infected regions, where ICU beds may be in short supply); (Seasonal flu normally causes about 200,000 hospitalizations every year);

(c) 30,000 – 90,000 deaths; (For reference, about 36,000 people typically die annually of the seasonal flu. About 90 percent of these are over 65, but in contrast for the swine flu, younger victims are more at risk because their immune systems have never been exposed to a virus with these surface characteristics.)

The H1N1 strain never took the summer lull that public officials anticipated, contributing to anxiety that the fall outbreak could be worse than planned. Eighteen students at Carnegie-Mellon University in Pittsburgh, PA have recently been diagnosed with swine flu.

Pay close attention to the news as we get closer to October and see how this story unfolds.

L. Stephen Cole, M.D. is the Director of the Supercentenarian Research Foundation and a Visiting Scholar at the UCLA School of Engineering.

You may also like...

Leave a Reply