Viral Vaccines:
Balancing the Risks and Benefits
By Christine Climer
With so many vaccinations on the schedule already and many more in the pipeline, you might feel a little overwhelmed. Hepatitis A, chicken pox, polio … What’s the real benefit of all these shots?
A look at hepatitis A
Hepatitis A is the most common type of hepatitis reported in the United States, according to the Centers for Disease Control (CDC). The virus is acquired through contact with an infected person or by ingesting contaminated food or water. Good hygiene and frequent hand-washing help prevent the spread of the hepatitis A.
Infected people are most contagious the week or two before any symptoms appear. Children younger than 6 who become infected with hepatitis A usually have no symptoms at all, while older children and adults more frequently develop jaundice or flu-like symptoms. Complications are most likely to occur in older adults.
Unlike its cousin hepatitis B, hepatitis A does not cause long-term ill effects. In fact, the virus may actually be beneficial to some children. In a study published in October 2003, researchers at Stanford University School of Medicine demonstrated how the hepatitis A virus prevents the development of allergies in genetically susceptible children. “This is the first molecular explanation for how hygiene can affect allergies and asthma,” said Dale Umetsu, M.D., Ph.D., professor of pediatrics.
Since people can only get hepatitis A once, most cases occur among children and young adults. It is unknown just how long the vaccine protects from infection, so it’s possible that vaccinated children may be vulnerable later in life. This vaccine is currently only recommended for use in moderate- to high-risk locations, so check with your physician to see if it is recommended in your area.
So what about chicken pox?
You probably had chicken pox as a child and know many other kids who sailed through what was once considered a right of passage. Indeed, the CDC states that the illness is generally mild in normal, healthy children. Complications are most likely to occur in adults, anyone who is immune-compromised and babies less than one year of age.
So why are we vaccinating for this generally benign illness? The answer depends on whom you ask. The U.S. Food and Drug Administration’s Philip R. Krause, M.D., says, "The hope is that if enough healthy children get the vaccine, there will be less natural chicken pox floating around, and [high-risk] people will not be exposed." According to the CDC, varicella (chicken pox) is the leading cause of vaccine-preventable deaths in children in the United States.
Economics play a part. The CDC claims that “cost-benefit studies have demonstrated that when societal costs are considered as well as direct medical costs, $5.40 is saved for every $1 spent on varicella vaccination in children.” Societal costs include the number of days of school children miss while ill and the number of days of work that parents and caregivers miss due to caring for them. However, if you subtract the indirect costs and consider only the direct medical expenses associated with chicken pox, this vaccine doesn’t save anyone money at all because the disease just isn’t generally that bad.
The most common complications of chicken pox include pneumonia and bacterial infection of the sores. If your child develops chicken pox, it is important to take care at home to prevent this infection.
Things you can do at home to prevent itching and bacterial infection
Bathe daily. Add about one-half to one cup of a soothing colloidal oatmeal preparation, cornstarch or baking soda for extra relief.
Change clothing and linens daily (or more often if soiled).
Apply calamine lotion as directed by your physician. Colloidal oatmeal creams work well, too. Wash your own hands with soap and water before applying anything to your child’s sores.
Keep your child’s fingernails trimmed short and clean.
Keep your child occupied to decrease his focus on the itching.
Teach your child to press on itchy areas or apply clean, cool compresses instead of scratching. Scratching will break the skin and spread germs.
Avoid using fever-reducing medications.
If your child is still in diapers, change him as soon as he’s soiled and at least every hour or two.
Depending on your child’s symptoms, some of these tips may also be helpful.
Chicken pox vaccine: Why not?
During a recent chicken pox outbreak at a New Hampshire child care center, a child vaccinated three years earlier infected more than half of his classmates who had no history of ever having the illness. While the vaccine manufacturer claims a much higher efficacy rate for the vaccine, researchers in this case found the vaccine to only be 44% effective. This might not be quite what you expect when you have your toddler vaccinated to prevent chicken pox.
In a study of another outbreak, Barna D. Tugwell, M.D., and colleagues found a vaccine effectiveness rate of 72% and evidence that immunity wanes over time following vaccination. “Booster vaccination may deserve additional consideration,” they noted. Just as one dose of measles vaccine historically became two, it is likely that one dose of varicella vaccine will become two or more.
Also as we’ve seen with measles, as varicella incidence drops among children, young adults will lose their source of natural immune boosting. They will become susceptible to infection in adulthood, when complications are more likely, and they will also be more likely to develop shingles. The manufacturer’s website itself attests to this fact. Natural chicken pox results in life-long immunity. A robust immune system following natural infection keeps the virus at bay, preventing shingles.
Mothers who have poor immunity to the virus will pass on less protection to their babies. This means that babies will become susceptible to the illness at a younger age than those born to mothers who successfully recovered from chicken pox and experienced the boosting effect from the virus circulating in their communities.
Protected from polio
Polio is the poster child for vaccination success. The last case of polio in the United States was in 1979, but outbreaks continue to occur in developing countries. As sanitation practices improve, transmission of the three viruses that cause polio decreases.
You’ve probably seen pictures or heard stories about how the illness caused “acute flaccid paralysis,” crippling children during the first half of the 20th century. But what you may not know is that according to the CDC, 95% of polio infections have no symptoms at all and less than 1% result in paralysis.
Polio is a “stomach virus” that is transmitted in the same way as hepatitis A. It passes through the gastrointestinal tract and may occasionally progress to the bloodstream, where it can gain access to the nervous system under the right conditions.
The old oral polio vaccine (OPV) stimulates the immune system right where the virus enters -- at the gastrointestinal mucosa -- so it is very effective at teaching the body to control the viruses quickly. The problem was that the vaccine is made with live, weakened viruses that, once ingested, could revert back to their original strength and cause illness. Once polio had been eradicated in this part of the world, health officials determined that the risk of the vaccine was worse than the risk of the disease, so they decided to switch to the inactivated (killed) virus vaccine (IPV) that we use today. This vaccine is injected and makes antibodies in the bloodstream, as opposed to the quicker, mucosal immune response given by OPV.
According to the American Academy of Otolaryngology, children who have had tonsils and adenoids removed are more vulnerable to polio because of the missing mucosal immune function that tonsils and adenoids provide.
Although most parents diligently vaccinate their children with IPV, if there is ever a polio outbreak in the United States, it is likely that OPV will again be administered to control the disease. The National Vaccine Advisory Committee has recently convened a workgroup that is outlining recommendations for stockpiling and using OPV in the event of outbreak.
For more information about polio or any other illnesses, speak with your health care provider and visit the references and resources listed below.
Resources
Learn more about the vaccines by accessing the manufacturer’s prescribing information:
Hepatitis A – Vaqta or Havrix
Chicken Pox
Inactivated Polio
Learn more about polio and the history of the vaccines from Janine Roberts’ online research notes.
References
1. American Academy of Otolaryngology Website Content
2. CDC. Epidemiology and Prevention of Vaccine-Preventable Diseases, 8th Edition online version.
3. CDC. Varicella and Herpes Zoster Clinical Questions & Answers
4. CDC. Varicella-Related Deaths Among Children -- United States, 1997.
MMWR 1998: 47(18);365-8.
5. Edmunds WJ, Brisson M. The effect of vaccination on the epidemiology of varicella zoster virus. J Infect. 2002 May;44(4):211-9.
6. Galil, K et al. Outbreak of Varicella at a Day-Care Center despite Vaccination
N Engl J Med. 2002 Dec 12;347(24):1909-15
7. GlaxoSmithKline Prescribing Information
8. Merck & Co, Inc. Prescribing Information
9. Merck & Co., Inc. Prescribing Information
10. Merck & Co., Inc. Website Content
11. NVIC Statement
12. NVPO Website Content
13. Porretto, D. Is It Worth a Shot? Better Homes and Gardens. February, 1999.
15. Stanford School of Medicine News Release
16. Stehlin, IB. First Vaccine for Chicken Pox. FDA Consumer Magazine. September, 1995.
17. Tugwell BD, et al. Chickenpox outbreak in a highly vaccinated school population. Pediatrics. 2004 Mar;113(3 Pt 1):455-9.
Whaley L and Wong D (1991). Nursing Care of Infants and Children, Fourth Edition. St. Louis, Missouri: Mosby-Year Book, Inc.
© Christine Climer
Christine Climer is a registered nurse with experience in pulmonary disease, pediatrics, home health and hospice services. Also trained in early childhood education, she is currently executive director and child care nurse for an early childhood health promotion organization. She lives with her husband and three children (including a set of twins) in Texas and enjoys researching health issues and gardening.
