H1N1 vaccine fears may fuel pandemic, undercut hospital, public health response
Doubts, rumors and lingering fears of 1976
A witch's brew of apathy, fear, and misinformation about the H1N1 influenza A vaccine may cause considerable toil and trouble for clinicians responding to the first pandemic in four decades.
Public health officials are concerned about the perceived reluctance of millions of people to be immunized with a fast-tracked vaccine for what many dismiss as a mild infection. To rephrase the old anti-war slogan, what if they made a vaccine and nobody took it?
"I'm concerned that H1N1 vaccine will be left in the refrigerator," says William Schaffner, MD, chairman of the department of preventive medicine at Vanderbilt University School of Medicine in Nashville, TN. "Vaccine in the refrigerator has never prevented a case of influenza."
A recent survey by the Harvard School of Public Health found that just 40% of adults are "absolutely certain" they will get the H1N1 vaccine for themselves, and 51% of parents are "absolutely certain" that they will get the vaccine for their children. Public health discussions and focus groups suggest the country is split on the issue, with roughly half the population reluctant to take the H1N1 vaccine for one reason or another, says Schaffner, a member of the board of directors of the Infectious Diseases Society of America.
"Some [are thinking] that this is a mild infection and there is no need to get vaccinated," he says. "The other issue is about the safety of the vaccine — the rapidity with which it was produced and the fact that it is a new vaccine for a new virus."
For example, concerned people in Missouri are asking public health officials about circulating stories that the H1N1 vaccine is dangerous and some of the early recipients have actually died, says Eddie Hedrick, BS, MT(ASCP), CIC, emerging infections coordinator at the state health department in Jefferson City, MO.
"Just last night, I got this frantic e-mail from a lady — you could just feel her anxiety," he says. "There's something going around — I guess on the Internet — because I keep hearing it from different people as though it happened in their neighborhood. I've heard it from all segments of the state. It's taken on a life of its own."
Some of the fear may be traced back to 1976, when a disastrous flu vaccine campaign unfolded that still resonates today. To put it indelicately, 40 million people were vaccinated for a pandemic that never occurred and some of them didn't live to tell about it. That incident is often cited as one of the reasons health care workers historically have spurned the flu shot, though they generally seem to be less concerned about the flu vaccine this year than the public. Infection preventionists tell Hospital Infection Control & Prevention their seasonal flu campaigns have gone better than usual, with workers lining up and rolling up their sleeves.
"And the most frequently asked question when they come through the line is, 'When will the H1N1 vaccine be available?'" Schaffner says. There is some concern that health care workers are less enthusiastic about inhaling the mist version, which includes live, attenuated H1N1 virus. Responses approach rebellion when the vaccine is mandated for health care workers (e.g., New York state), but the immunization — contrary to rumor — is strictly voluntary for the public.
In that regard, if enough people choose to remain unvaccinated, the public health and hospital response could grow increasingly difficult as the pandemic moves into the winter months.
"There is no way to stop a pandemic other than with a vaccine," Hedrick says. "All the community mitigation measures are designed to do is knock the surge down. The idea is to save your resources. Once you get to a certain point, your resources are overwhelmed. If half the people aren't getting vaccinated you're going to see that many more people getting sick and it's going to put a strain on all resources — not just health care. It actually derails the response because you can't knock it down and maintain the status quo without the vaccine."
Hospitals in particular are not likely to have adequate supplies or staffing if they are besieged by patients for prolonged periods. "It's already happening," Hedrick says. "In St. Louis the other day, there were two hospitals that were 30% over their surge capacity."
Influenza, lest we forget, kills 36,000 people in a run-of-the mill year in the United States. Yet, despite the recent highly publicized H1N1 deaths of high-risk patients such as children and pregnant women, many people are expected to snub the 2009 vaccine because the vast majority of infections have been clinically uneventful. That truth doesn't tell the whole story though, as a minority of cases on the other end of the spectrum may take an aggressive course that will not stop short of the intensive care unit. For some people, the decision to refuse the vaccine — for whatever reason — will prove fatal.
"This year already, we have seen quite a few children who have died from flu," Thomas Frieden, MD, CDC director, said at a recent press conference. "So, although it is not a disease that will send lots of people to the hospital, it can be very serious and even for those for whom it's an average case, it's no picnic. You would rather avoid it for yourself and your kids [by being vaccinated]."
Though the H1N1 vaccine production and clinical trials were highly publicized, the vaccine was actually made — for all practical purposes — like every seasonal flu vaccine created in relative obscurity annually, he added.
"Each year, we look at the strains that are circulating and we look at the ones that are likely to be in the population," Frieden explained. "We put those into the flu vaccine. That's exactly what has been done in this case, specifically against H1N1 influenza. [It was] made in the same production facilities with the same companies with the same methods as it is made each year. Hundreds of millions of [seasonal flu] doses have been given. My children will get it."
While the benefits clearly outweigh a risk that is currently imperceptible, Frieden concedes that any side effects could take considerable time and many vaccinations to detect. Vaccine problems would likely occur at a very low rate, perhaps 1 per 100,000 immunizations, he said. The CDC already is anticipating that some people who have underlying health problems that coincidentally surface after being immunized will ascribe their condition to the vaccine.
"Many people, each week, develop health problems — a miscarriage, a heart attack, even tragically a sudden death," Frieden said. "Some people who get the flu vaccine will experience some bad outcome. We will look at each report to see if it's related, and if — in the overall group — there's any sign of an increase rate of adverse events. We'll share that information publicly. We're committed to transparency."
For those who argue that H1N1 already has hit their area and thus it is "too late" to be vaccinated, Frieden stresses that even in areas where flu is considered "widespread," 90% to 95% of the population still is susceptible.
"Our biggest concern is that the virus could change, mutate to become more deadly," he said. "We have seen nothing [to suggest] that would be the case. So far, in fact, the virus has been quite stable genetically. The part of the virus that determines whether or not it's very deadly is a different part of the virus that determines whether or not you're going to be protected by the vaccine. That's good news. Because, it means that the vaccine that we have now, which is very effective — very tightly matched with the virus that's spreading — is likely to protect you even if this virus were to become more deadly."
In addition, the ultimate severity of any given H1N1 infection is not predictable. The CDC warned about this early in the emerging pandemic in discouraging "swine flu parties," where one presumably raises a glass to herd immunity by cohorting with the symptomatic. A sobering antidote to that mentality are the reports of severe infections in young, healthy people. The World Health Organization has described a severe form of H1N1 infection "rarely seen during seasonal influenza" that appears to now be occurring in some U.S. cases. But few scenarios match the emotional impact of the death of an expectant mother, where H1N1 — in the absence of some extraordinary circumstance — essentially takes two lives for one infection.
"The H1N1 influenza in pregnancy has really been striking," says Anne Schuchat, MD, director of the National Center for Immunization and Respiratory Diseases at the CDC. "We have obstetricians here at CDC who are coordinating the outreach as well as the surveillance efforts around it. And they're talking to doctors around the country who have never seen this kind of thing before."
In cases reported through late August, 28 pregnant women died of H1N1 infection and at least 100 have been hospitalized in ICUs. "We haven't in the past tracked seasonal flu complications in pregnancy," Schuchat said at a press conference. "Whether this is more common or people are just noticing it because we're attending to this H1N1 virus, it's difficult to say. But I think the obstetric caregivers [at CDC] and the ones that we're speaking with have rarely seen this kind of thing in practice."
Season flu immunization has long been recommended for pregnant women, but few partake of the annual shot. They are now strongly recommended to take the H1N1 injectable vaccine — not the mist version containing live, attenuated virus. The latter is recommended primarily for healthy people ages 2 to 49. For his part, Schaffner thinks the H1N1 toll on pregnant women is a surveillance artifact — finding something because you are looking harder for it.
"The obstetricians are having to address — for the first time by the vast majority of them — this issue of influenza immunization of pregnant women," he says. "Frankly, the [H1N1] deaths in pregnant women are now being tallied and reported in real time. We have done that with [flu] deaths of children, but we haven't given deaths of pregnant women the same public attention in the past."
It was not reported how many of the severely infected pregnant women had bacterial coinfections. In a separate CDC report of 77 fatal cases of H1N1 infection among various types of people, roughly a third had coinfections with bacteria such as Streptococcus pneumoniae, and methicillin-resistant Staphylococcus aureus. H1N1 and bacterial coinfections were not unexpected, but it is nevertheless another complicating aspect of the pandemic.
"The good news is the leading bacteria was Streptococcus pneumoniae, and we have a vaccine for that," Schuchat says. "Adults are recommended to receive the pneumococcal vaccine if they have chronic medical conditions, like asthma, diabetes, chronic heart disease, chronic lung disease, immunosuppression and so forth. Sadly, only about one in five nonelderly adults take advantage of that vaccine. So, when people are going in for their seasonal flu vaccines right now — those very same [at-risk] people — we urge them to consider the pneumococcal vaccine that is available right now."
Speaking of the elderly, the issue of the pneumococcal vaccine raises another strange aspect to this pandemic: Older people usually urged to receive the "pneumonia shot" and the seasonal flu vaccine are low on the list to receive the H1N1 immunization. Typically devastated by flu and first in line for shots, those over 65 apparently have residual immunity to H1N1. The paradox is that they are not likely to be infected, but if they are, they are more likely to have a fatal case.
"The case fatality ratio is highest in people age 65 and older," Schaffner says. "If those people get infection with H1N1, their risk of a serious result is actually the highest. But their risk of getting initial infection is the lowest. One of the remarkable things about the epidemiology of H1N1 is that it has [generally] spared people age 65 and older. There has yet to be a nursing home outbreak — that is really striking."
That means, in some sense, that the elderly may have circulating antibodies from some former flu infection, exposure, or vaccine in some forgotten year. We'll leave it to the medical researchers to ponder if 1976 could have been one of them.
A witch's brew of apathy, fear, and misinformation about the H1N1 influenza A vaccine may cause considerable toil and trouble for clinicians responding to the first pandemic in four decades.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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