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Fall 2001

Treatment advisory
Flu Shots:  Weigh the Risks

Physicians who treat patients with chronic fatigue syndrome (CFS) must balance the benefits of an annual influenza vaccination against concerns that the inoculation will exacerbate CFS symptoms.

Here are two physicians' views on the use of flu vaccines in CFS patients:

Charles Shepherd, MD
On the plus side, the vaccine should provide a fairly high degree of protection against the particular strains of flu virus that seem likely to occur over the coming months. This is important because a bout of flu will almost certainly cause a relapse or marked worsening of symptoms in people with CFS. In addition, influenza can trigger life-threatening complications in patients with underlying conditions such as diabetes or heart, lung or kidney disease.

However, physicians must be aware of concerns that the vaccine itself can cause problems in CFS patients. There are a number of anecdotal reports (but no firm evidence published in the scientific literature) of people with CFS experiencing a relapse in symptoms following the use of flu vaccines.

In a survey I carried out a few years ago, a total of 21 people with CFS responded to a request for information about what happened following flu vaccination.  Seven had no problems at all whereas 13 reported an exacerbation of symptoms that ranged from mild (3 of 13) to moderate (7 of 13) to severe (3 of 13).  There also was an interesting report involving a teenager who noticed a considerable degree of improvement in symptoms following vaccination. These results are very similar to the general feedback I continue to receive on this subject.

It is impossible to predict who is more likely to suffer an adverse reaction or relapse following use of the influenza vaccine. However, anecdotal reports suggest that this may be more likely to occur in people who have ongoing infective-type symptoms (sore throats, enlarged glands, problems with temperature control, etc.). In this situation, I would personally advise against having a flu vaccine unless there are very good reasons for doing so.

I also would advise against flu vaccinations if a patient is in the very early stages of CFS, particularly when it obviously follows an infective episode. In addition, I would avoid administering the vaccine if the patient has previously experienced an adverse reaction to flu shots. Patients who have not shown adverse reactions to influenza vaccines in previous years will probably handle the latest vaccine without any real problems, even though the preparation varies annually.

Charles Shepherd, MD, is medical director of the Myalgic Encephalopathy Association (MEA) in the United Kingdom.

Stanley N. Schwartz, MD
There is no good evidence-based medicine knowledge to support or refute the often-repeated notion that people with CFS should not have vaccinations. The theory is that people with CFS have certain overactive immune mechanisms that may be further stimulated by a vaccination, leading to worsening of symptoms. We now know that immune dysfunction is not a uniform part of the pathology of CFS.

I have heard that theory repeated by many physicians with experience in treating CFS patients. However, I am unaware of any systematically collected observations to prove the point.

During the past several years, I have observed a few patients with CFS who have developed a major influenza infection. In each case, a major exacerbation of the CFS occurred as a result of the infection. My experience has actually been different from other CFS doctors in that patients have seldom reported any significant problems after vaccination to me.

So here is my bottom line: we know that for certain people in high-risk groups, influenza can be serious or deadly. This is well established in the medical literature. I advise my patients that the decision to receive influenza vaccine should be made based on whether they meet the current Public Health Service criteria for vaccination.

If a person with CFS has any of those indications for the vaccine, I recommend it without hesitation. If a person with CFS is likely to be exposed to influenza and to pass it along to others (such as if he/she is a physician, nurse or other health care worker), I also recommend the vaccine.

If a person does not have one of the standard indications for the vaccine, I tell them that the decision to receive it has to be a personal decision and that there is no research to confirm or reject the theory that patients with CFS have more problems with the vaccine.

Stanley N. Schwartz, MD, is clinical professor of medicine at the University of Oklahoma College of Medicine-Tulsa, and sits on the board of directors of the American Association for Chronic Fatigue Syndrome.

For more information
The Centers for Disease Control and Prevention (CDC) offers treatment guidelines for physicians with questions about the use of influenza vaccinations. The CDC's Web site is http://www.cdc.gov/nip/flu.

The CDC reports that delivery of annual influenza vaccinations has been delayed once again this fall, though the situation promises to be better than in recent years. Officials estimate that 64 percent of the 83.5 million projected vaccine doses will be available by early November. The rest will be distributed by the end of December. The vaccine prepared for the 2001-2002 season will include A/Moscow/10/99-like (H3N2), A/New Caledonia/20/99-like (H1N1) and B/Sichuan/379/99-like antigens.