Simplifying Science

With All the Talk About Swine Flu Vaccine... Who is Willing to Give it to Their Child?

According to CDC, to date 9079 people have been hospitalized with novel H1N1 flu (AKA “Swine Flu”) and 593 have died from the disease. Almost everyone in the business of predicting what the winter flu season will look like agrees: H1N1 flu will be back with a vengeance. No one knows—or even knows how to predict—the burden that H1N1 will bring. No one can say with certainty how it will compare to seasonal (AKA “regular old”) flu; whether it will cause mild or serious disease; or whether it will infect by the thousands or by the hundreds of thousands.

The development of a vaccine against novel H1N1 began almost as soon as the virus was identified, and it is scheduled for licensure in October. Because CDC is not committing to a specific release date or to a number of doses that will be available, speculation has taken over traditional and Internet media with reports that the number of doses of the new vaccine will be insufficient to protect against pandemic spread of the virus. Front page headlines last month claimed 90,000 could die of the infection this year.

It is possible that the speculators are right. Epidemiologists say that enough doses of vaccine need to be administered in order to “protect” the sum total of us from a pandemic. But it is not at all clear what this number of doses is, who should be vaccinated first, or how much vaccine can be manufactured (let alone administered) in time for the onset of the winter flu season. In August, CDC published guidelines for vaccine priority. If the H1N1 vaccine supplies are severely limited, then the following groups should get it first: pregnant women, people who live or work with children under 6 months of age, healthcare and emergency medical services personnel, children 6 months to 4 years, and older kids (5–18 years) who have chronic medical conditions.

Here’s the intriguing paradox: there seems to be great public demand for the vaccine and there will certainly be outcry if it is not available in sufficient numbers to protect us all. But one of the top—and probably the largest—priority groups slated to get the vaccine first is not necessarily going to be lining up to get it. This is because the parents of young children have become vocal vaccine skeptics.

CDC has focused their vaccine priority on young children because this population is among the most effective vectors of disease transmission. Infants drool, they spit up, and they put just about everything they can in their mouths. Toddlers pick their noses, rub their eyes, and lick their fingers. Kids under the age of four are very good at sharing the bodily fluids that transmit flu viruses with everyone around them; they are far less good at washing their hands and practicing basic hygiene. If this single group can be vaccinated, not only will they be spared illness from H1N1 but their immunity should limit the rampant spread of the new virus.

So who is going to bridge this gap? Who is going to be able to convince parents already reluctant to vaccinate that they should give their children this vaccine? There cannot be an assumption that just because the vaccine is available, it will be utilized. A tremendous burden will rest with physicians who are going to have to find the time to talk to parents about the risks and benefits of a brand new vaccine that has very little data about its efficacy (does it work?), necessity (is H1N1 even that bad?) and toxicity (what are the side effects?). And this precious time is going to have to be found during the already busy back-to-school and winter flu seasons.

Here’s another hurdle: the majority of H1N1 vaccine will be in multi-dose vials. Any vaccine in a multi-dose vial must have a preservative. Translation: Most of the new vaccine will contain the mercury preservative thimerosal. And in some places—like my home state of California—it is against the law to immunize young children with thimerosal-containing vaccine. There is an aggressive attempt at producing single-dose (i.e. thimerosal-free) vaccine for pregnant women and young children, but there are no guarantees if and when this can be accomplished. The inclusion of mercury in the novel vaccine will undoubtedly present a roadblock.

Meanwhile, seasonal influenza will also reappear as it does every year. There is no reason that the existence of the new H1N1 virus will reduce the burden of seasonal flu.

People always want to know what the pediatrician does for her own kids. Well, I took mine in for their seasonal flu vaccines last month—something I typically do in late September or early October. This regular flu vaccine won’t cross-protect against H1N1, but it should protect my kids against this year’s garden-variety seasonal flu. I did this early so that if the H1N1 vaccine becomes available and if my kids even qualify (by age) to get a dose, they will have the option to get it. No one knows yet how the two different flu vaccines need to be timed; most reports suggest that they can be given simultaneously or they need a 3-4 week interval between administrations. By getting a seasonal flu vaccine early, my kids will pass the 4-week mark before the H1N1 vaccine even hits the shelves. Meanwhile, as the studies of the new vaccine are completed and safety data emerges, I will have another round of decisions to make come October.