Alleged link between hepatitis B vaccine and chronic
fatigue
syndrome
In 1989, 3456 cases of hepatitis B were reported in Canada. It is generally accepted that the true incidence of the disease is about 10 times the reported incidence. Hepatitis B virus is a major cause of acute and chronic hepatitis, cirrhosis and primary hepatocellular carcinoma. Chronic hepatitis may develop in 10% of infected adults and 90% of infected infants and may progress to cirrhosis and hepatocellular carcinoma. In its acute form hepatitis B is fatal in a small number of cases. The disease is transmitted through sexual contact and infected blood and other body fluids. Carriers frequently show no symptoms until later in life and may therefore infect others
unknowingly. Hepatitis B vaccine has been used in populations that have an established risk of infection with known consequences (e.g., health care workers, male homosexuals and injection drug users). Recent attention in the Canadian press has focused on the possible association between hepatitis B vaccination and chronic fatigue syndrome (CFS). CFS is a nonspecific condition whose cause is unknown. Definition of the syndrome has proven difficult because of the nature of the complaints. There is no objective test available to confirm or refute the diagnosis, which is made in part through the exclusion of other diseases. There are conflicting immunologic and viral data regarding the causes of CFS. One hypothesis is that it may be due to one or more immunologic disorders resulting from acquired infection. ' The Nightingale Research Foundation, incorporated as a charitable foundation in 1988, has recently issued a statement that CFS is linked to the administration of hepatitis B vaccine. This claim resulted in
part from a francophone television program in October 1990 on which a nurse contended that she had acquired CFS after receiving the vaccine. The program announced a toll-free number and encouraged viewers to call if they had similar experiences. Sixty-nine people contacted the television station. These reports were later forwarded to the Laboratory Centre for Disease Control (LCDC) for investigation. A questionnaire was developed to analyse possible trends in the symptoms reported and the latency between receipt of the vaccine and the onset of symptoms. Between March and June 1991, 60 of the 69 people or their parents were contacted after multiple attempts; all but 1 agreed to participate in the study. The age of the 59 people varied from 2 to 59 (mean and median 37) years. Fifty-one (86%) were female. The internationally recognized case definition of CFS of the US Centers for Disease Control2 was used to assess the prolonged fatigue, one of the two major criteria that must be satisfied. Thirty-one (53%) of the people met this definition. Hepatitis B vaccine had been administered to these patients between 1983 and 1990. All three hepatitis B vaccines thus far licensed for use in Canada were among those received; none was overrepresented in the study group in relation to the number of doses distributed. The time of onset of fatigue after vaccination varied from 1 hour to 1 year. Fourteen (45%) of the 31 patients reported having been given the following diagnoses before the study: fibromyalgia (5), CFS (2), multiple sclerosis (2), rheumatoid arthritis (2), depression (1), fibromyositis (1) and hepatitis (1). None of this information has yet been corroborated with the
Based on material previously reported in Canada Diseases Weekly Report (a publication of the Bureau of Communicable Disease Epidemiology, Laboratory Centre for Disease Control, Department of National Health and Welfare, Tunney's Pasture, Ottawa, Ont.) by the Field Epidemiology and Childhood Immunization divisions, Bureau of Communicable Disease Epidemiology (1991; 17: 215-216). Publication in CMAJ is with permission of the bureau. Reprint requests to: Bureau of Communicable Disease Epidemiology, Laboratory Centre for Disease Control, Tunney's Pasture, Ottawa, ON KIA OL2 JANUARY 1, 1992
CAN MED ASSOC J 1992; 146 (1)
37
treating physicians or the medical records. This investigation was complicated because health care providers were disproportionately represented but as a group were more likely to be vaccinated against hepatitis B. No conclusive epidemiologic association can be made at this time between any of these adverse events and the vaccine. In addition, there is no scientific basis to suggest that CFS can result from hepatitis B vaccination. Occasionally some medical events do occur coincidentally after vaccination that are not causally related to the vaccine. This is the first time such an allegation has been made of a possible association between CFS and hepatitis B vaccination. A workshop involving North American experts in CFS, held in Toronto in September 1989,3 did not identify this association. Furthermore, the World Health Organization and various centres across North America and Europe currently involved in the etiologic investigation of CFS do not consider the vaccine as a likely cause. Further investigation will be conducted to determine the actual diagnosis of the conditions that the people in the LCDC study had. LCDC will continue to monitor reported adverse medical events that occur after receipt of hepatitis B vaccine. Adverse reactions to any vaccine are of great
concern to public health officials in many countries. Nevertheless, despite careful vigilance by such officials serious reactions to hepatitis B vaccine are rarely found. An extensive review of postmarketing surveillance for adverse reactions is described by Shaw, Graham and Guess.4 Over 20 million doses of the plasma-derived and recombinant types of hepatitis B vaccine have been used worldwide. About one million doses have been distributed in Canada. According to postmarketing surveillance data the rate of any reported adverse event after the administration of one of the three licensed vaccines is about 22 per 100 000 doses distributed.
References 1. Landay AL, Jessop C, Lennette ET et al: Chronic fatigue syndrome: clinical condition associated with immune activation. Lancet 1991; 338: 707-712 2. Holmes GP, Kaplan JE, Gantz NM et al: Chronic fatigue syndrome: a working case definition. Ann Intern Med 1988; 108: 387-389 3. Proceedings of a workshop: Chronic Fatigue Syndrome, 28-29 September 1989, Toronto, Ontario. Can Dis Wkly Rep 1991; 17 (suppl 1 E): 1 -71 4. Shaw FE, Graham DJ, Guess HA: Postmarketing surveillance for neurological adverse events reported after hepatitis B vaccine. Am J Epidemiol 1988; 127: 337-352
With imore than 250 offices across North America providing comprehensive home health care and staffing services. For additional information, call us at 1-800-531-0974.
ANSWERING YOUR CALL FOR HELP. © 1991 T 01stt
38
CAN MED ASSOCJ 1992; 146(1)
CorToration
69-91
LE jer JANVIER 1992
fatigue
syndrome
In 1989, 3456 cases of hepatitis B were reported in Canada. It is generally accepted that the true incidence of the disease is about 10 times the reported incidence. Hepatitis B virus is a major cause of acute and chronic hepatitis, cirrhosis and primary hepatocellular carcinoma. Chronic hepatitis may develop in 10% of infected adults and 90% of infected infants and may progress to cirrhosis and hepatocellular carcinoma. In its acute form hepatitis B is fatal in a small number of cases. The disease is transmitted through sexual contact and infected blood and other body fluids. Carriers frequently show no symptoms until later in life and may therefore infect others
unknowingly. Hepatitis B vaccine has been used in populations that have an established risk of infection with known consequences (e.g., health care workers, male homosexuals and injection drug users). Recent attention in the Canadian press has focused on the possible association between hepatitis B vaccination and chronic fatigue syndrome (CFS). CFS is a nonspecific condition whose cause is unknown. Definition of the syndrome has proven difficult because of the nature of the complaints. There is no objective test available to confirm or refute the diagnosis, which is made in part through the exclusion of other diseases. There are conflicting immunologic and viral data regarding the causes of CFS. One hypothesis is that it may be due to one or more immunologic disorders resulting from acquired infection. ' The Nightingale Research Foundation, incorporated as a charitable foundation in 1988, has recently issued a statement that CFS is linked to the administration of hepatitis B vaccine. This claim resulted in
part from a francophone television program in October 1990 on which a nurse contended that she had acquired CFS after receiving the vaccine. The program announced a toll-free number and encouraged viewers to call if they had similar experiences. Sixty-nine people contacted the television station. These reports were later forwarded to the Laboratory Centre for Disease Control (LCDC) for investigation. A questionnaire was developed to analyse possible trends in the symptoms reported and the latency between receipt of the vaccine and the onset of symptoms. Between March and June 1991, 60 of the 69 people or their parents were contacted after multiple attempts; all but 1 agreed to participate in the study. The age of the 59 people varied from 2 to 59 (mean and median 37) years. Fifty-one (86%) were female. The internationally recognized case definition of CFS of the US Centers for Disease Control2 was used to assess the prolonged fatigue, one of the two major criteria that must be satisfied. Thirty-one (53%) of the people met this definition. Hepatitis B vaccine had been administered to these patients between 1983 and 1990. All three hepatitis B vaccines thus far licensed for use in Canada were among those received; none was overrepresented in the study group in relation to the number of doses distributed. The time of onset of fatigue after vaccination varied from 1 hour to 1 year. Fourteen (45%) of the 31 patients reported having been given the following diagnoses before the study: fibromyalgia (5), CFS (2), multiple sclerosis (2), rheumatoid arthritis (2), depression (1), fibromyositis (1) and hepatitis (1). None of this information has yet been corroborated with the
Based on material previously reported in Canada Diseases Weekly Report (a publication of the Bureau of Communicable Disease Epidemiology, Laboratory Centre for Disease Control, Department of National Health and Welfare, Tunney's Pasture, Ottawa, Ont.) by the Field Epidemiology and Childhood Immunization divisions, Bureau of Communicable Disease Epidemiology (1991; 17: 215-216). Publication in CMAJ is with permission of the bureau. Reprint requests to: Bureau of Communicable Disease Epidemiology, Laboratory Centre for Disease Control, Tunney's Pasture, Ottawa, ON KIA OL2 JANUARY 1, 1992
CAN MED ASSOC J 1992; 146 (1)
37
treating physicians or the medical records. This investigation was complicated because health care providers were disproportionately represented but as a group were more likely to be vaccinated against hepatitis B. No conclusive epidemiologic association can be made at this time between any of these adverse events and the vaccine. In addition, there is no scientific basis to suggest that CFS can result from hepatitis B vaccination. Occasionally some medical events do occur coincidentally after vaccination that are not causally related to the vaccine. This is the first time such an allegation has been made of a possible association between CFS and hepatitis B vaccination. A workshop involving North American experts in CFS, held in Toronto in September 1989,3 did not identify this association. Furthermore, the World Health Organization and various centres across North America and Europe currently involved in the etiologic investigation of CFS do not consider the vaccine as a likely cause. Further investigation will be conducted to determine the actual diagnosis of the conditions that the people in the LCDC study had. LCDC will continue to monitor reported adverse medical events that occur after receipt of hepatitis B vaccine. Adverse reactions to any vaccine are of great
concern to public health officials in many countries. Nevertheless, despite careful vigilance by such officials serious reactions to hepatitis B vaccine are rarely found. An extensive review of postmarketing surveillance for adverse reactions is described by Shaw, Graham and Guess.4 Over 20 million doses of the plasma-derived and recombinant types of hepatitis B vaccine have been used worldwide. About one million doses have been distributed in Canada. According to postmarketing surveillance data the rate of any reported adverse event after the administration of one of the three licensed vaccines is about 22 per 100 000 doses distributed.
References 1. Landay AL, Jessop C, Lennette ET et al: Chronic fatigue syndrome: clinical condition associated with immune activation. Lancet 1991; 338: 707-712 2. Holmes GP, Kaplan JE, Gantz NM et al: Chronic fatigue syndrome: a working case definition. Ann Intern Med 1988; 108: 387-389 3. Proceedings of a workshop: Chronic Fatigue Syndrome, 28-29 September 1989, Toronto, Ontario. Can Dis Wkly Rep 1991; 17 (suppl 1 E): 1 -71 4. Shaw FE, Graham DJ, Guess HA: Postmarketing surveillance for neurological adverse events reported after hepatitis B vaccine. Am J Epidemiol 1988; 127: 337-352
With imore than 250 offices across North America providing comprehensive home health care and staffing services. For additional information, call us at 1-800-531-0974.
ANSWERING YOUR CALL FOR HELP. © 1991 T 01stt
38
CAN MED ASSOCJ 1992; 146(1)
CorToration
69-91
LE jer JANVIER 1992
