Bacterial Vaccines: Who Needs Them?
By Christine Climer
Diphtheria, tetanus, pertussis – the names of these diseases conjure horrifying illnesses that modern medicine has rendered impotent through vaccinations. At the other end of the spectrum are vaccinations like Prevnar and Hib, the new kids on the block that doctors say will help prevent diseases that continue to nettle American children.
So what are these diseases and their related vaccines? Do the diseases represent real threats to your child’s health today? Does your child need all these vaccines?
What is diphtheria?
Diphtheria is caused by a toxin released by the bacteria C. diphtheriae. These bacteria only release their toxin when a specific virus infects them. This toxin can damage tissue in the throat, nerves and the heart, which can result in abnormal heart rhythms and difficulty breathing. People with diphtheria are usually given antibiotics to kill the bacteria as well as an antitoxin, which is produced in horses, to neutralize circulating toxin.
Though the disease is rare, the bacteria continue to circulate in the United States without causing typical symptoms. Recent outbreaks in the former Soviet Union have been attributed largely to unavailable health care infrastructure, lack of sanitation services and inadequate supply of food and clean water.
What is tetanus?
Tetanus is a disease caused by toxins released by the bacteria C. tetani. These bacteria are commonly found in soil, manure and even the human intestinal tract. When the bacteria enter a wound, if there is very little oxygen, the toxins can be released into the body. These toxins interfere with nerve function, causing muscle spasms, seizures and difficulty breathing or swallowing.
Proper wound care is crucial to the prevention of tetanus. If a wound is properly cleaned and cared for, the bacteria should not be able to thrive. Puncture wounds are most commonly associated with tetanus because these wounds are most likely to have low oxygen levels. Patients with tetanus are usually given tetanus immune globulin (TIG) to neutralize circulating toxin.
What is pertussis?
Pertussis is an illness that is most severe among infants. B. pertussis bacteria attach themselves to cilia, the tiny hairs lining the respiratory tract. The bacteria release toxins that damage cilia and cause inflammation. Because cilia are responsible for helping clear mucus from the airway, people with pertussis tend to develop a cough as a means of compensating for difficulty clearing mucus.
It is not uncommon for older children and adults to have pertussis, but their symptoms are often so mild that it appears as no more than a common cold or mild bronchitis. Infants are most at risk of complications such as pneumonia due to their tiny airways and lack of immune experience. During severe coughing attacks, babies may turn blue or vomit.
The most severe phase of the illness usually lasts one to six weeks but has been known to persist for 10 weeks. Antibiotics may lessen the severity of the illness if begun early on. Otherwise, treatment focuses on simple supportive measures.
The pertussis vaccine protects for only a few years, at most. As vaccination coverage has increased over the past 20 years, so has the number of reported cases of pertussis. It is unclear at this time whether this is reflective of an actual increase in disease incidence or whether more reports are being made, as physicians are realizing pertussis frequently occurs even in vaccinated communities and have begun actively looking for it in ill patients.
The “meningitis” and the “ear infection” vaccines
Vaccines for diphtheria, tetanus and pertussis have been available since the 1950s, but Prevnar and Hib (Haemophilus influenzae type b) are newcomers to the vaccine scene. Hib was first added to the recommended vaccination schedule in 1991 and Prevnar was added in 2000.
Prevnar has received much attention as being “the ear infection vaccine.” Yet Wyeth, the vaccine’s manufacturer, states that protection against ear infections “is expected to be low” and that children who have received the vaccine have an increased risk of developing ear infections caused by other bacteria. Your decision to use this vaccine should be based solely on their effect on invasive disease such as meningitis and septicemia (blood infection).
Your physician may be eager to promote Prevnar and Hib vaccines because of their ability to prevent meningitis in some children, but it’s important to realize that many different types of organisms cause meningitis. The bacteria in these vaccines represent only a very small portion of those organisms, and vaccinated children can still get meningitis.
In fact, according to vaccine manufacturers and the Centers for Disease Control, if Prevnar and Hib are administered to a child under six weeks of age, the baby could develop “immune tolerance.” Because newborn immune systems are just learning to function, early vaccination with these vaccines makes babies unable to respond to these germs -- and so they are actually more susceptible to infection. And since scientists don’t thoroughly understand how newborn immune systems work, some parents question whether it is actually possible for immune tolerance to occur in some older babies as well.
The incidence of invasive diseases peaks between the ages of six and 18 months. Your child may have an increased risk of developing invasive Hib or pneumococcal disease if she:
is not breastfed
attends group child care
has older siblings
is immune-compromised or has a chronic disease
has taken antibiotics
has had at least one ear infection in the past three months
A peculiarity has been noted among physicians who administer the Prevnar and Hib vaccines. Dr. Jeanne Santoli of the CDC’s National Immunization Program has expressed concern over a recent Harvard study, which found that these doctors are less likely to perform diagnostic testing such as blood work and urine screening when children present with symptoms of potential bacterial illness. Many cases of bacterial illness go undetected because the doctors just aren’t looking. This also means that children with urinary tract infections are less likely to receive appropriate medical care.
What’s in these vaccines?
Prevnar and Hib vaccines are made in a similar way. The outer coatings of these bacteria are polysaccharides (sugar molecules linked together). The immature immune systems of babies are not able to recognize those outer coatings unless they are attached to a protein, so the vaccines are made by taking pieces of the bacterial coatings and attaching (conjugating) them to a protein from another bacteria. Prevnar uses diphtheria protein and Hib vaccines use either tetanus, diphtheria or meningococcal protein.
Most of these vaccines contain aluminum adjuvants. An adjuvant is added to some vaccines to increase and prolong the immune response; without the adjuvant, the vaccine would not work. Adverse reactions to these adjuvants include sterile abscesses, allergies and increased swelling, redness, tenderness and nodule formation at the vaccination site. “Aluminum also is a neurotoxin,” says Dr. Philip Rudnick, Professor Emeritus of Chemistry at West Chester University of Pennsylvania. “This has been known for over 100 years.” A neurotoxin is a substance that damages the tissues of the nervous system.
The pertussis vaccine component has been linked with the development of neurologic disorders, as well. Due to the high number of adverse reactions to this vaccine, the whole-cell pertussis component has been replaced in recent years by an acellular version that produces fewer reactions. Pertussis-containing vaccines are never administered to children over seven years of age, due to an increased risk of such reactions.
Contrary to what has been frequently reported in the media, some of these vaccines still contain thimerosal (a mercury-containing preservative). There has been much controversy in recent years as to whether thimerosal has the potential to cause regressive autism. In any case, mercury is a toxic substance that should be avoided. U.S. Representatives Dave Weldon, M.D., (R-FL) and Carolyn Maloney (D-NY) have recently introduced legislation to eliminate mercury from vaccines.
Quality control issues?
The United States has recently experienced shortages of Prevnar. News coverage has since reported that the vaccine’s manufacturer has fired a manager at the manufacturing plant for allegedly raising concerns about quality control and the potential for vaccine contamination or failure. The manufacturer has denied any safety problems, but the possibility is one that may, quite understandably, weigh heavily on your mind.
An ecosystem in balance
When evaluating the risks and benefits of these bacterial vaccines, it’s helpful to understand a little bit about the amazing ecosystem we each have in and on our bodies. There are millions of tiny bacteria that live on the outside of our bodies, inside our mouths and noses and throughout or gastrointestinal system. These bacteria live in a symbiotic relationship with us: we provide the proper environment and nutrients to assure their growth, and they in turn provide us with valuable nutrients, keep disease causing germs in check and help our immune systems to function properly. This bacterial population is known as our normal flora.
When something causes the population to become unbalanced, illness can occur. Our normal flora protect us from colonization by “potentially pathogenic organisms,” germs which have the potential to make us sick under just the right circumstances, by competing for nutrients, producing substances that kill or injure other germs and affecting environmental conditions such as pH and oxygen levels.
Some of the bacteria these vaccines strive to eradicate are actually carried as part of the normal flora in some people and never cause any illness. Individuals who have an unhealthy normal flora balance or those who are compromised in some way -- inadequate nutrition, stress, injury or immune system suppression -- are most likely to get sick from these opportunistic bacteria.
When Hib and pneumococcal vaccine components are eliminated from our normal flora, there is an increased likelihood of colonization and infection with other non-vaccine strains. This tendency has serious implications for the future of infectious disease and may well increase the number of vaccines required.
Bacteriotherapy, or using harmless bacteria to displace disease-causing germs, might be an interesting alternative. “Bacteriotherapy seems to be a promising candidate for the future treatment and prevention of respiratory tract and gastrointestinal infections,” says Dr. Pentti Huovinen, chief physician at the National Public Health Institute in Finland. Recent research demonstrates that ingesting certain “probiotic” bacteria decreases carriage of some potentially pathogenic organisms such as Hib, pneumococci and Staphylococci, which caused an unusually high number of complications this past flu season. As opposed to vaccination, which merely eliminates these bacteria, bacteriotherapy actually rebalances the ecosystem.
For more information about bacterial vaccines and the illnesses discussed above, speak with your health care provider and investigate the resources and references below.
Resources
· To learn more about meningitis, visit MUSA.
· To access prescribing information for all the vaccines mentioned above and to view thimerosal content, visit Dr. Neal Halsey’s Institute for Vaccine Safety.
· To search the VAERS database of adverse vaccine reactions, visit Medalerts.
· To learn more about the principles of disease and epidemiology, review the corresponding chapters in Microbiology: An Introduction by Tortora, Funke and Case. This is a textbook that can frequently be located at used bookstores, college bookstores and college campus libraries.
References
1. Aventis Pasteur Prescribing Information
2. Centers for Disease Control Epidemiology and Prevention of Vaccine-Preventable Diseases, 8th Edition online version.
3. Centers for Disease Control National Immunization Program. ““Epidemiology & Prevention of Vaccine-Preventable Diseases” satellite broadcast, Session II, February 26, 2004.
4. Centers for Disease Control National Immunization Program. “Record of the Meeting of the Advisory Committee on Immunization Practices, February 26-27, 2003.”
5. Centers for Disease Control National Immunization Program. “Record of the Meeting of the Advisory Committee on Immunization Practices, October 15 16, 2003.”
6. Centers for Disease Control National Immunization Program. “Vaccine Safety Issues of Interest”
7. Centers for Disease Control Update: Influenza Activity-- United States, 2003-04 Season. MMWR 2003; 52(49);1197-1202.
8. Cripps AW, Foxwell R, Kyd J. Challenges for the development of vaccines against Haemophilus influenzae and Neisseria meningitidis. Curr Opin Immunol. 2002 Oct;14(5):553-7.
9. Gluck U, Gebbers JO. Ingested probiotics reduce nasal colonization with pathogenic bacteria (Staphylococcus aureus, Streptococcus pneumoniae, and beta-hemolytic streptococci). Am J Clin Nutr. 2003 Feb;77(2):517-20.
10. Gupta RK, Siber GR. Adjuvants for human vaccines--current status, problems and future prospects. Vaccine. 1995 Oct;13(14):1263-76.
11. Huovinen P. Bacteriotherapy: the time has come. BMJ. 2001 Aug 18;323(7309):353-4.
12. Inpharma Weekly, Opinion and Evidence in Respiratory Medicine. Pneumococcal Vaccination in the Pediatric Population. Am J Respir Med. 2002;1(1):75-76.
13. Institute of Medicine. Immunization Safety Review: Vaccines and Autism
14. Kiser KB, Cantey-Kiser JM, Lee JC. Development and characterization of a Staphylococcus aureus nasal colonization model in mice. Infect Immun. 1999 Oct;67(10):5001-6.
15. Levine OS, Farley M, Harrison LH, Lefkowitz L, McGeer A, Schwartz B. Risk factors for invasive pneumococcal disease in children: a population-based case-control study in North America. Pediatrics. 1999 Mar;103(3):E28.
16. Lipsitch M. Bacterial vaccines and serotype replacement: lessons from Haemophilus influenzae and prospects for Streptococcus pneumoniae. Emerg Infect Dis. 1999 May-Jun;5(3):336-45.
17. Merck & Co., Inc. Prescribing Information
18. Mulholland EK. Conjugate pneumococcal vaccines: an overview. Med J Aust 2000 Oct 2;173 Suppl:S48-50
19. Obaro SK. Confronting the pneumococcus: a target shift or bullet change?
Vaccine. 2000 Dec 8;19(9-10):1211-7.
20. Obaro SK, Adegbola RA, Banya WAS, Greenwood BM. Carriage of pneumococci after pneumococcal vaccination. Lancet 1996;348:271-2.
21. Spratt BG, Greenwood BM. Prevention of pneumococcal disease by vaccination: does serotype replacement matter? Lancet. 2000 Oct 7;356(9237):1210-1.
22. TEST Foundation, Website Content
23. Texas Department of Health, Immunization Division. “Licensure Dates for Vaccines and Toxoids, United States.”
24. Tortora GJ, Funke BR, Case CL. Microbiology: An Introduction. 5th Ed. Redwood City, California: Benjamin/Cummings Publishing Company, Inc., 1995. ISBN 0-8053-8496-0
25. U.S. Representative Dave Weldon, MD, Website Content
26. Wyeth Prescribing Information
27. Wyeth Prescribing Information
© 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.
