Overview
The federal government is moving closer to approving a chicken pox (varicella) vaccine for children and adults. A Food and Drug Administration (FDA) advisory panel decided the experimental vaccine was “safe and effective,” however, FDA must still approve the vaccine. This live-virus vaccine has been proposed to be combined with MMR (measles, mumps, rubella) vaccine and administered to children at 12 months of age. Data are unavailable concerning how long the vaccine will protect against chicken pox, or the need for boosters. The manufacturer, Merck & Co., has not shown that the vaccine can protect for more than four to five years. (Contrast this to lifetime immunity when one contracts the disease naturally.) Merck acknowledges that anyone over 12 years of age will need two shots. A repeated concern about chicken pox vaccine is its unknown potential to cause shingles (herpes zygote; 1, 2).
Incidence and death rates
Approximately 3.9 million cases of chicken pox occur annually in the United States, killing an estimated 90 persons (0.0023% death rate). Although chicken pox is considered a relatively harmless disease of childhood (90% of cases occur in children under 10 years of age; peak age of incidence = 5-9 years (3)) with generally mild and rarely severe complications, the push to research and license a chicken pox vaccine stems from the significant complication and mortality rate among high-risk persons. These groups include children with leukemia, or persons receiving steroids, e.g., patients with cancer, arthritis, kidney disease, organ transplants, or asthma. Steroids are known to suppress immunity, leaving the patient sometimes defenseless against what would normally be harmless diseases. Immunocompromised persons comprise only an estimated 0. 1% of all chicken pox cases.
Adults are another high-risk group for chicken pox complications, some requiring hospitalization for pneumonia and possibly resulting in death. The hospitalization rate for adults with chicken pox is 14 to 18 hospitalizations per 1,000 cases, compared to 1 or 2 hospitalizations per 1,000 cases for children. Adults comprise only 2% of chicken pox cases, but are responsible for 47.5% of deaths.
The estimated death rate for chicken pox is 1.4 per 100,000 cases (0.00 14%) in normal children, but rises to 30.9 deaths per I 00,000 cases (0.0309 %) in adults. The death rate is 7% in children with leukemia.
Normal children I to 14 years of age are estimated to be responsible for 30 to 40% of chicken pox deaths, mainly due to the large proportion of total cases occurring in this age group (over 90% of cases occur in this age group). However, this still represents a very low death rate (less than 0.0023%) for chicken pox (4, 5).
Could use of chicken pox vaccine in all children make matters worse?
Dr. Philip Brunnell, head of pediatric infectious disease at Cedars Sinai Hospital in Los Angeles was cited in The New York Times (6) that to justify giving all children a vaccine for a disease that is essentially harmless, the vaccine must be totally risk-free.
Additionally a widespread national chicken pox vaccination program might shift the incidence of chicken pox to older ages (adults), where the complication and death rate rise sharply. (This happened to measles disease in response to routine use of measles vaccine in children. hi the highly publicized measles resurgence in the late 1980s and early 90s about half the cases occurred in adolescents and adults, most with a history of measles vaccination as a young child.) But, the government’s solution is just to give additional booster doses of chicken pox vaccine.
As noted above adults currently comprise only 2% of chicken pox cases, but are responsible for 47.5% of the deaths. By shifting the incidence of chicken pox disease to adults, which may well occur with a universal chicken pox vaccination program, a larger number of chicken pox deaths per total cases may actually result.
Will chicken pox vaccine save money in the long run?
A recent study (7) noted that “at a cost of $35 for each vaccine dose, a routine varicella vaccination program for preschool-age children will not save money from the health care payer’s perspective, but would still be desirable and would save money from the societal perspective.” Another study (8; supported by a research grant by the vaccine maker Merck) reported a similar conclusion.
This means that unless lost time from work (wages) are factored into the cost: benefit analysis for a parent to stay home from work to care for a sick child, there is no cost advantage to vaccinate all children against chicken pox.
A more common-sense approach would be to allow children to return to school sooner than now recommended. Many schools and daycare centers do not allow children to return to school until the last spot has crusted over, feeling that children are contagious until this occurs. However, children are most contagious before the spots appear, or when they first appear. Therefore, Dr. Brunell recommends to send children back to school earlier than currently allowed, which is when most children feel better anyway. This, he asserts, is an easier way to reduce the costs of chicken pox to society, as opposed to vaccinating everyone (6).
Dr. Walter Orenstein, Director, CDC National Immunization Program, who will have a great deal to say about recommending chicken pox vaccine for all children, described being kept up for several nights with his five-year-old during a bout of chicken pox, admitting, “It’s that kind of problem that the vaccine would eliminate rather than serious disease (6).
How effective is chicken pox vaccine?
chicken pox vaccine is estimated to be 95% effective in children however, the vaccine fails to protect in up to 30% of adults with close exposure to someone with chicken pox, e.g., children in the same household (9).
But, as is claimed by proponents when other vaccines fail to protect against disease, chicken pox vaccine proponents likewise assert that persons catching chicken pox in spite of vaccination have “milder” cases (9-11).
Even sick children will be injected with chicken pox vaccine combined with MMR vaccine. One study (12) concluded “that sick children develop similar immunities to measles, mumps, rubella, and varicella viruses” (as measured by blood antibody levels) as well children. Although the study design was deficient and involved only 149 children, this study will be cited to defend the acceptability of vaccinating sick children. Vaccine safety concerns were not mentioned in this study. (The federal government cites failure to vaccinate sick children as a “barrier” to reaching federal and state vaccination goals.)
Will chicken pox vaccine be optional?
Probably not. Even though chicken pox vaccine has yet to be licensed by the FDA, due to incomplete safety and efficacy data, the Centers for Disease Control and Prevention (CDC) has reportedly proposed to administer chicken pox vaccine at age 12 months, in combination with MMR (measles, mumps, rubella) vaccine.
Although the head of the CDC panel which would recommend chicken pox vaccine for all children, Dr. Sam Katz, was quoted by the Associated Press that “parents are knocking on the door saying they want this vaccine” (13), parents who don’t want chicken pox vaccine for their children will be ignored.
Several U.S. states automatically mandate all vaccines recommended by the CDC, and nearly all other states eventually comply. Additionally, federal budget legislation from August, 1993 mandates that if a state wishes to receive federal money for state vaccination programs, the state must recommend all federally recommended (i.e., CDC recommended vaccines.
The only way that children will be exempt from the chicken pox vaccine mandate will be if they actually had chicken pox disease. Therefore, parents should obtain a written, signed note from a physician to confirm that the child actually had chicken pox disease.
Taking photographs of children while they are infected with chicken pox is also prudent. State vaccination laws for other diseases do not usually accept a parent’s memory that his/her child actually had a disease-only a doctor’s note is proof Alternately, a blood test to show antibody levels usually will exempt a child from required vaccines. A note from a physician is less expensive than a blood test.
It is your “civic duty” to vaccinate
More than one author has suggested that by vaccinating all healthy children, high-risk children, such as those with leukemia, will be protected from chicken pox.
Huse et al. (8) suggested that widespread use of chicken pox vaccine could reduce “transmission of varicella to immunocompromised or other susceptible persons,” and “may reduce the risk of congenital or neonatal varicella resulting from infection of pregnant women.” This latter risk appears small (less than 1%; 4, 14). Additionally, susceptible hospital workers would be less likely to spread chicken pox to hospital patients if the workers’ children were vaccinated. Others have recommended chicken pox vaccine for health care workers (15, 16).
A proponent of routine chicken pox vaccine, Dr. Anne Gershon of Columbia University, wrote: “At this time, because of the complexities involved in immunizing leukemic children, there seems to be a greater interest in vaccinating healthy varicella-susceptible individuals rather than leukemic children. If immunization with varicella vaccine were recommended for all 15-month-old infants, most children who become immunosuppressed because of development of leukemia would already have been immunized against varicella-zoster virus (9).”
It is, therefore, Dr. Gershon’s opinion that, instead of vaccinating just a few high-risk children, we should vaccinate millions of healthy children every year against chicken pox when they are 15-months-old to protect leukemic children against chicken pox. Another benefit of vaccinating healthy children, according to Dr. Gershon, is that if these once healthy children happen later to develop leukemia, at least they’ll be protected against chicken pox.
Children as “guinea pigs”
Dr. Arthur Lavin, Department of Pediatrics, St. Luke’s Medical Center in Cleveland, Ohio wrote in The Lancet (17) of “three concerns … (he) believe(s) argue strongly against die licensure of varicella vaccine for healthy children.”
- chicken pox “is not major in the sense of disease mortality or morbidity. In childhood, mortality is very low, and morbidity is usually minor … Therefore, if healthy children were fully vaccinated it is unclear in what significant way the health of the children or the economic health of their families would be improved.”
- Routine chicken pox vaccination in healthy children might pose a “grave danger of advancing the age of onset of chicken pox into adulthood.” After bemoaning adults’ poor compliance with vaccine recommendations, e.g., influenzae vaccine, Dr. Lavin asks, “What makes the proponents of universal varicella immunization believe that adults who may be susceptible to varicella as a result of their efforts would protect themselves with a booster dose (of chicken pox vaccine)?”
- Dr. Lavin has deep concerns “about injecting millions of young children with a mutant strain of herpes virus. As is well known, herpes viral DNA insinuates itself into the human genome for the lifetime of a host …. Although the risk of a deleterious effect on the human genome from an injected mutant herpetic viral genome is remote, the application of this risk to hundreds of millions of hosts increases the chance that we will see some adverse effect” (emphasis added).
Dr. Lavin concludes:
“Humanity has been well served through efforts that have eliminated smallpox and nearly eradicated poliomyelitis and measles. However, not all infections demand these interventions (emphasis added). The Varicella immunization Program may be too much of a good thing (emphasis added). Until we actually know the duration of immunity and the risks involved in injecting mutated hepatic DNA into the host genome, I argue strongly against licensing this vaccine for use in all children.”
Conclusion
It appears that chicken pox vaccine will be mandated by law, not to benefit healthy children, but to save time and money for their parents with jobs outside the home, to protect children with cancer from catching chicken pox from other children, or for parental convenience so that parents will not have to stay up for two or three nights caring for their children with chicken pox
But, as Dr. Lavin states above (17), what price might society pay for this convenience
By Kristine M. Severyn, R.Ph., Ph.D.
References:
- Chicken pox vaccine moves closer to FDA approval (Associated Press), ‘[‘he Washington Post 1/28/94, p. A 11.
- Simini, B., (letter), The Lancet, 343: 1363, 1994
- Nelson Textbook of Pediatrics, 14th edition W.B. Saunders Co., Philadelphia, 1992. p. 801.
- Preblud, S.R., Varicella: complications and costs. Pediatrics 78: 728-735, 1986.
- Feldman, S. and Lott, L., Varicella in children with cancer: impact of antiviral therapy and prophylaxis. Pediatrics 80: 465-472, 1987.
- Rosenthal, E., Doctors weigh the costs of a chicken pox vaccine. The New York Times, 7/7/93, p. 1.
- Lieu, T.A. et al., Cost-effectiveness of a routine varicella vaccination program for US children. 271: 375-381, 1994.
- Huse, D.M., et al., Childhood vaccination against chicken pox: an analysis of benefits and costs. The Journal of Pediatrics 124(6): 869-874, 1994.
- Gershon, A.A., vari vaccine: still at the crossroads. Pediatrics 90: 144-148, 1992.
- Bernstein, H.H., et al., Clinical survey of natural varicella compared with breakthrough varicella after immunization with live attenuated Oka/Merck varicella vaccine. Pediatric 92(6): 833-837, 1993.
- Watson, B.M., et al., Modified chicken pox in children immunized with the Oka/Merck varicella vaccine. Pediatrics 91(l): 17-22, 1993.
- Dennehy, P.H. et al., Seroconversion rates to combined measles-mumps, rubella, vaccine of children with upper respiratory tract infection. Pediatrics 94(4): 514-516, 1994.
- Approval near for chicken pox shot (Associated Press) The Washington Times, 11/27/93.
- Siegel, M., et al., Comparative fetal mortality in maternal virus diseases: a prospective study on rubella, measles, mumps chicken pox, and hepatitis. New England Journal of Medicine 274: 768-771, 1966.
- Lewis, D.A., et al., Varicella-zoster vaccination for health care workers (letter). The Lancet 343: 1362-1363, 1994.
- Boughton, C.R. Varicella-zoster vaccine. Medical Journal of Australia 159: 439440, 1993,
- Lavin, A., (letter), The Lancet 343: 1363, 1994.
This article appeared in the Autumn, 1994 newsletter of Ohio Parents for Vaccine Safety, and is reproduced with the organization’s permission. To subscribe to this newsletter, write to:
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