A Shot of Protection

Q. Why is it important for dental professionals to keep their vaccinations up-to-date?

A. Vaccinations are one of the fundamental components of an overall infection control program. They provide long-term immunity without the necessity for repeated administrative antibiotics. Protective vaccines have been developed against a number of common infections, such as influenza, pneumococcal pneumonia, measles, mumps, rubella, and polio.

Vaccination immunology has been a component of clinical science since the late 1700s when Dr. Edward Jenner developed the first smallpox vaccine and administered it to people in England. Since then, vaccinations have become an effective public health strategy for minimizing the impact of a number of life threatening infections on the population. Vaccinations are also important to health care professionals because many of these infections can present occupational risks. Many of these infections can be transmitted during the provision of care from infected patients, prior to the onset of symptoms. By receiving the recommended vaccines, health care workers can further protect themselves.

FIGHTING THE FLU

Q. Which vaccinations are the most important for health care professionals?

A. Hepatitis B is a major occupational infection to be immunized against, since it is the most infectious blood-borne pathogen and can be readily transmitted in health care settings via accidental exposure to blood. Hepatitis B virus is the microbial organism that was used to develop the universal and current standard infection control precautions. It is a widespread infection throughout the world and presents major occupational risks for unprotected dental and medical professionals. The vaccine, which was first introduced in 1982, has been well received by health care professionals. As a result of the vaccine’s success, along with improved infection control precautions, the incidence of hepatitis B in dental and medical health care workers has dropped precipitously. Hepatitis B vaccination is now required for all health care professionals.

Another important immunization is the influenza vaccine. This is an annual vaccine administered to protect against highly infectious airborne pathogens. Influenza is a very acute infection that knocks people off their feet for 5 to 7 days with severe muscle aches, fever, headaches, raspy cough, and a general run-down feeling. People don’t realize just how common the flu is, and as a result, they don’t treat it with the same seriousness as other diseases. This vaccine is typically injected, although a more recently developed version can be administered as a nose spray.

The injected influenza vaccine contains components of three inactivated viruses. The vaccine virus strains are initially grown in chick embryo cultures, then harvested, inactivated, and split into components. There isn’t any intact virus—live or inactivated—in the vaccine preparation. It takes about 4 to 6 weeks to develop very high-levels of antibody that are specific for the strains of influenza circulating in the population that year. Health care, including dental professionals, are at very high risk of exposure to people with undiagnosed cases of influenza, and therefore are among the groups highly recommended for vaccination.

Influenza virus is very efficiently spread person-to-person by aerosols, such as through sneezing and coughing. It can also be spread through direct contact with contaminated hands, which makes proper hand hygiene integral to preventing influenza transmission. Using the correct barrier protection, ie, gloves; the appropriate hand hygiene agent; maintaining healthy, intact skin; keeping nails short with smooth edges; and utilizing an effective handwashing protocol are all key to reducing the risk of infection.

Q. Do most health care professionals get vaccinated against the flu?

A. No, many dental and medical health care workers still do not get the influenza vaccine on an annual basis. A common excuse is that they “don’t get sick.” What they don’t realize is that influenza symptomatology is much more dramatic than other flu-like illnesses, including a severe cold. They are putting themselves at risk for a serious illness by not getting vaccinated. Another major reason people don’t get vaccinated is because of the common misconception that you can get influenza from the vaccine.

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VACCINE-PREVENTABLE DISEASES

Anthrax

Cervical Cancer
Diphtheria
Hepatitis A
Hepatitis B
Hæmophilus influenzæ type b (Hib)
Human Papillomavirus (HPV)
Influenza
Japanese Encephalitis (JE)
Lyme Disease
Measles
Meningococcal
Monkeypox
Mumps
Pertussis (Whooping Cough)
Pneumococcal
Poliomyelitis (Polio)
Rabies
Rotavirus
Rubella (German Measles)
Shingles (Herpes Zoster)
Smallpox
Tetanus (Lockjaw)
Tuberculosis
Typhoid Fever
Varicella (Chicken Pox)
Yellow Fever

Centers for Disease Control and Prevention. Vaccines and Immunizations. Available at: www.cdc.gov/vaccines/vpd-vac/default.htm. Accessed December 7, 2007.

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RISKS VS BENEFITS

Q. Are there risks associated with vaccinations?

A. Inflammation at the site of a vaccine injection is possible and may cause a low grade fever and some myalgia. The same stimulus that allows inflammatory cells to move in to trigger an effective, protective immune response may cause this reaction. Reactions to vaccines are also very individualized. Some people have more negative reactions than others. However, when considering the overall public health value of influenza vaccinations, they are absolutely crucial for the overall health of the population, especially for the elderly and those with immune compromised defenses. These individuals have a much higher risk of secondary pneumonia after contracting influenza, thus, it is very important for them to comply with influenza vaccine recommendations.

Q. Should health care professionals get the chicken pox vaccination?

A. The varicella (chicken pox) vaccination is indicated for health care professionals who did not have chicken pox when they were young. They are at risk of contracting it from people they treat and, unfortunately, adult cases of chicken pox tend to be much more severe than childhood cases. In addition, a health care worker who has active chicken pox can spread it to patients who may not have had the infection. This scenario could be very serious, especially when dealing with immune compromised individuals on either end.

A very high percentage of young children have been vaccinated against chicken pox since 1995, when the vaccine was first released. This has resulted in a dramatic decline in new cases of varicella, which also has lessened the risk for people who have never contracted chicken pox. Even with this demonstrated success, the vaccine is still appropriate as chicken pox continues to exist in the population. As an off-shoot of varicella vaccine science, a licensed herpes zoster or shingles vaccine is now available. The latter is a modification of the chicken pox vaccine, primarily an increased dose of the varicella vaccine given to people 60 years and over to minimize the potential for recurrent varicella-zoster virus infection, which leads to shingles. This vaccination restimulates the body’s immune response to varicella-zoster virus that is latent in the sensory nerve cells located near the spinal cord.

To summarize, for those health care workers who have never had chicken pox there is the Varivax vaccine, and for those who have had chicken pox or are at increased risk of developing shingles—such as people over 60—there is Zostavax, the shingles vaccine.

Q. Is the pertussis vaccine necessary for dental professionals?

A. Pertussis or whooping cough is one of the more recent re-emerging diseases. It is also a problem for clinicians because it is a difficult disease to diagnose. In the mid 1970s, there were less than 1,500 cases of pertussis in the United States. However, by 2001, this number had risen to more than 10,000 cases. The re-emergence is caused in part by the inclusion of the latest form of pertussis vaccine with the diphtheria and tetanus vaccine or DPT. Immunity against Bordetella pertussis following receipt of DPT appears to wane during adolescence. This respiratory infection can also be misdiagnosed because the current manifestations of pertussis do not necessarily include the classic “whooping”cough of years ago. This characteristic sound is missing from the cough, and the patient instead presents with a more chronic, prolonged cough. It has been referred to as the “100 day cough.” Diagnosis can also be problematic because Bordetella pertussis is a difficult organism to culture and isolate. Because a resurgence of this respiratory infection is occurring in adolescence and even adults, health care professionals should be aware and protected.

THE BIG PICTURE

Q. Are there any new vaccinations on the horizon that dental professionals should consider getting?

A There is an ongoing effort to create a hepatitis C vaccine in part because an effective cure for hepatitis C does not currently exist. There are some treatments with promise, but the infection can still persist for life in carriers and cause serious health impairments.

Q. How is Hepatitis C transmitted?

A. It is primarily blood-borne. It’s not as efficiently transmitted sexually or perinatally from mother to offspring, but it does happen. One of the major problems with developing an effective hepatitis C vaccine is that the virus changes during infection. It possesses a feature called genetic diversity, in that with each replication cycle in the liver, viral components can become altered in structure. These changes in surface components subsequently make the virus appear different to the body’s immune defenses. Thus, the host immune system is constantly trying to catch up and respond to new antigens that are emerging with each replication cycle. Scientists have not found a stable antigen yet that would enable them to develop a vaccine.

Q. What is the importance of vaccines for world health?

A. In 1999, vaccination was listed by the CDC as one of the 10 greatest achievements of the 20th century. Vaccinations have changed the face of infectious diseases by lowering the incidence dramatically of many infectious diseases that were quite common less than 50 years ago, and have resulted in increasing health and life expectancy of the population.

Diseases that were rampant in areas where antibiotics were unavailable or where the medical system was not advanced enough to treat these infections have been controlled by vaccinations. Some of these diseases have virtually disappeared from the face of the earth as a result of ongoing vaccination programs. Examples include smallpox, which has been eradicated, and poliomyelitis, which is getting close to elimination. Unfortunately, in some countries were vaccine programs have been cut back, the incidence of polio has started to increase again.

Vaccinations play a very important role in public health. They’re a good way to protect the overwhelming majority of populations without re-administration of antibiotics or other types of medications that would be far more costly, time consuming, and almost impossible to deliver in many areas of the world.

From Dimensions of Dental Hygiene. January 2008;6(1): 20, 22, 24.