Vaccines Provide Vital Dose of Immunity
Which vaccines should you receive?
Vaccinations are a foundational practice in the effort to limit the spread of infectious diseases. Outbreaks of vaccine-preventable diseases, such as whooping cough, have been associated with infected healthcare personnel (HCP) and, in recent years, have led to increased awareness regarding the need for HCP immunization.1 This has even resulted in multiple states requiring certain vaccines, notably influenza, for HCP.2 While not all vaccines are 100% effective, they play an important role in the achievement of community immunity, which means a critical number of people have been vaccinated against a disease.
In the United States, vaccine recommendations are made by the Advisory Committee on Immunization Practices (ACIP), which functions within the Centers for Disease Control and Prevention. As new vaccines are developed and scientific knowledge regarding immunizations advances, recommendations change frequently, including those for boosters or newly developed vaccines. HCP, including dental healthcare personnel (DHCP), should be aware of recommendations for vaccines and ensure immunizations are up-to-date, particularly because many communicable diseases are just a plane ride away.
Poliomyelitis, commonly referred to as polio, was widespread in the United States prior to 1955, with 13,000 to 20,000 individuals paralyzed annually. Polio also had accounted for 1,000 deaths each year in the United States alone.3 Because of the widespread vaccine use beginning in the mid 1950s, polio was successfully eradicated by 1979 in the United States. Although the disease is expected to be eradicated globally within the next 10 years,3 parts of the world still experience polio outbreaks and people traveling to those regions should check with their physicians to determine if boosters are indicated.
The inactivated polio vaccine (IPV) is administered to children beginning at 2 months of age, with a second dose at 4 months, a third between 6 and 18 months, and a final booster dose between the ages of 4 and 6 years.4 This vaccine is often given in combination with the diphtheria, tetanus, and acellular pertussis vaccine (Dtap) and hepatitis B vaccines, which will be discussed later.
Measles, Mumps, and Rubella
Measles was widespread in the United States before the 1963 development of a vaccine. In developing countries, the disease remains common and often fatal, with the World Health Organization reporting 164,000 deaths attributed to measles in 2008.5
Mumps is airborne and can cause serious complications, including deafness, meningitis, testicular or ovarian inflammation, and other less common conditions.
Rubella, although not related to measles, is sometimes called German measles because the German medical literature was the first to describe it as a separate disease.3 The potential complications are particularly significant for pregnant women because infants born to mothers who had rubella early in their pregnancies can be born with severe congenital disorders, including deafness, blindness, cardiac deformities, and other organ abnormalities.
The measles, mumps, and rubella (MMR) vaccine is always given as a combination vaccine, sometimes also including the varicella vaccine. The four-vaccine combination is called the MMRV. The first dose is given between the ages of 12 and 15 months, with a second dose given between ages 4 and 6 years.5
This vaccine is most commonly associated with side effects that may cause some mild discomfort. These include injection-site pain, fever, mild rash, and swollen glands. Rarely, more serious side effects can occur, such as higher fever accompanied with seizures.
Varicella, commonly referred to as chickenpox, can be spread to nonimmune individuals through contact with persons with either herpes zoster, also known as shingles, or through breathing the same air as a person infected with varicella. Individuals infected with varicella may be contagious for as long as 3 weeks before lesions appear.3 The period of contagion without symptoms combined with the fact that it is spread via the airborne route makes this disease particularly easy to spread once it takes hold in an unvaccinated population. Although complications are relatively rare, they can be significant and may include pneumonia, infection, or inflammation of the brain, sepsis, toxic shock syndrome, bone infections, and joint infections. Although less than 5% of cases occur in people older than age 20, 55% of deaths due to varicella or its complications occur in that age group.3
Even though a person has been vaccinated, disease contraction is still possible if exposure occurs because the immunity conferred by the vaccine wanes. Such breakthrough infections,3 as they are called, are less severe. Children who were previously vaccinated but experience a breakthrough infection will be less contagious than infected children who were never vaccinated. In these cases, the lesions are rarely bulbous or hemorrhagic, meaning they are less inclined to blister and bleed. The lesions in a breakthrough infection are also less likely to cause residual scarring. So, even though a vaccinated person can still acquire a mild case of varicella, the vaccine is strongly recommended for individuals who have no history of past infection.
In young children, the varicella vaccine is given in two doses: one at ages 12 to 15 months and the second at ages 4 to 6 years.5 Because the vaccine has only been available in the US since 1995, it is also recommended that adults and children older than 13 with no history of varicella receive the vaccine.5 It is still given in two doses. However, in older individuals, it only needs to be at least 28 days apart. This vaccine is recommended for all healthcare workers. Between 70% and 90% of adults do not remember having varicella but have blood antibodies, indicating infection at some point in their lives. Some may have had very few lesions or even subclinical cases and therefore did not realize they were infected. A blood test performed before giving the vaccine can detect those antibodies. If they are present, the vaccine is not needed.
Herpes zoster (shingles) is also vaccine preventable. Herpes zoster is caused by the varicella zoster virus and only occurs in people who have had past infections with varicella.3 People are more likely to develop zoster at an older age, although immunocompromised persons have an increased risk for developing herpes zoster at any age. Despite its name, it is not related to herpes simplex.
The zoster vaccine, Zostavax®, is recommended specifically for individuals ages 60 and older.5 However, it is approved for adults ages 50 and older. This is not recommended as a routine healthcare worker immunization.
Tetanus, Diphtheria, and Pertussis
In recent years, a surge of pertussis (whooping cough) cases has been highlighted in the popular media. Unvaccinated adults or those who have not received the booster can transmit the disease to infants who are too young to have yet received the pertussis vaccine. This has resulted in a pertussis epidemic that has lasted the past several years throughout the US.
Pertussis remains poorly controlled in the US for the reasons previously mentioned. In 2009 alone, 16,858 cases and 12 infant deaths from pertussis were reported to the US Public Health Service.3 The spread of pertussis can only be stopped by widespread use of the Tdap vaccine for adults. As of 2010, however, less than 6% of the adult US population had received that Tdap booster needed to control pertussis. It is especially important for HCP to be vaccinated because they may serve as a source of infection to susceptible contacts, including patients, coworkers, and family.7
Tdap is given as a single dose and should be given regardless of when the individual last received the tetanus booster.5 Subsequent tetanus boosters should be provided on 10-year interval schedules.
Influenza, or the flu, has been responsible for several devastating pandemics throughout the years. In 1917 to 1918, just as World War I was ending, pandemic influenza is believed to have killed 50 million people worldwide, more than 3 times the deaths in the war. Additional pandemics have occurred in 1957 and 1968. In 2009, H1N1, known as swine flu, spread from the northern to the southern hemispheres, continuing to propagate illness after the end of the typical flu season. The World Health Organization declared it a level-6 pandemic—the highest level.3 Fortunately H1N1 did not cause severe illness, and most people did recover.
Because the flu can result in serious illness and death, ACIP recommends annual flu vaccinations for everyone ages 6 months and older.6
Hepatitis B virus (HBV) is a serious illness that can be transmitted when a susceptible person comes into contact with the blood or other body fluids of a person harboring the virus. HBV may occur as an acute infection, which may or may not cause symptoms. Persons with acute infections can transmit the virus via body fluids. Most adults infected with HBV will clear the virus, develop natural antibodies, and will not be able to transmit hepatitis to others after the acute phase. A small percentage of adults and a large percentage of infants infected at birth will develop chronic infection. These individuals will have virus circulating in their bodily fluids for prolonged periods, many for a lifetime.3
The HBV vaccine is especially important for HCP because overwhelming evidence indicates that HCP, including DHCP, are at an elevated risk for occupational exposure to HBV. The virus is able to survive for prolonged periods on environmental surfaces and can be transmissible even when no visible blood is present.7 The vaccine for adults consists of 3 injections given over a 6-month period.5 Current recommendations include a birth dose for all infants. Some variations in HBV vaccinations exist, including a 2-dose vaccine sometimes given to adolescents and combination vaccines that include HBV, Dtap, and inactivated polio vaccine sometimes given to young children. Also available is a 2-dose immunization that combines the vaccines for hepatitis B and hepatitis A.3
One important element of HBV vaccination is post-vaccine testing. All HCP should have post-vaccine testing for surface antibodies (anti-HBS). The testing should be conducted 1 to 2 months after completion of the series. If the result is anti-HBS negative, an additional dose of vaccine should be given, followed by anti-HBS testing 1 to 2 months later. If no immune response occurs at that point, two additional doses should be given one month apart and anti-HBS testing performed 1 to 2 months later. Alternatively, an HCP worker who does not respond to the initial series can repeat the 3-injection series over a 6-month period and then have anti-HBS testing 1 to 2 months later.7
The Bloodborne Pathogens Standard from the Occupational Safety and Health Administration (OSHA) requires employers to offer all at-risk employees HBV vaccination within 10 days of employment.8 OSHA also mandates employers to pay for the recommended post-vaccine anti-HBS testing. Employees may decline vaccination, but only after having been educated regarding the safety and efficacy of the vaccine and the possible consequences of not being vaccinated.
The bacteria Streptococcus pneumoniae can cause several types of infections, including pneumonia, ear infections, sinus infections, meningitis, and bacteremia (bloodstream infection).3 Two different vaccines are available to prevent infection. The pneumococcal conjugate vaccine (PCV13) is recommended for all children younger than 5 years old and for adults with certain risk factors. Children 2 years or older who are at high risk for pneumococcal disease should also receive the pneumococcal polysaccharide vaccine (PPSV23). All adults 65 or older and those 19 or older with risk factors should receive PPSV23.5
Immunizations are an important element in protecting communities against infectious disease outbreaks. Many vaccine-preventable diseases carry a risk for serious, sometimes fatal, complications. Although known side effects can be associated with vaccines, most are mild and no scientific evidence links vaccines with the development of autism in young children. One published study that claimed to show a correlation between the MMR vaccine and autism was later discredited and retracted. No other researcher has been able to replicate those results. Some vaccines may contain egg products, and anyone with an egg allergy should discuss the safety of receiving the vaccine with a medical professional.
The vaccinations listed in this article are generally recommended for children and adults in the United States. Additional vaccines may be indicated when working with certain high-risk populations, and when working, traveling, or living in areas known for harboring specific diseases not normally seen in the United States. In addition, several vaccines that are limited to specific age groups are not included in this article, including HPV and Hib. Always consult with a medical professional regarding which vaccines are indicated for yourself and your children. Discuss the risks and benefits of vaccines, including the potential consequences of not being vaccinated, with a physician or other health professional.
1. Talbot TR. Update on immunizations for healthcare personnel in the United States. Vaccine. 2013. https://dx.doi.org/10.1016/j.vaccine.2013.10.090.
2. Stewart AM, Cox MA. State law and influenza vaccination of health care personnel. Vaccine. 2012;31(5):827–832. https://dx.doi.org/10.1016/j.vaccine.2012.11.063.
3. Epidemiology and Prevention of Vaccine-Preventable Diseases. Atkinson W, Wolfe S, Hamborsky J, eds. 12th ed. Washington DC: Public Health Foundation; 2012.
4. Prevots DR, Burr RK, Sutter RW, Murphy TV; Advisory Committee on Immunization Practices. Poliomyelitis prevention in the United States. Updated recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2000;49(RR-5);1-22.
5. Centers for Disease Control and Prevention. Advisory Committee on Immunization Practices (ACIP) recommended immunization schedules for persons aged 0 through 18 years and adults aged 19 years and older—United States, 2013. MMWR Surveill Summ. 2013 62(suppl 1):1.
6. Centers for Disease Control and Prevention. Prevention and control of seasonal influenza with vaccines. Recommendations of the Advisory Committee on Immunization Practices—United States, 2013–2014. MMWR Surveill Summ. 2013;62(RR-07):1-43.
7. National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC. CDC guidance for evaluating health-care personnel for hepatitis B virus protection and for administering postexposure management. MMWR Surveill Summ. 2013;62(RR-10):1-19.
8. U.S. Department of Labor. Occupational Health and Safety Administration. https://www.osha.gov. Accessed February 4, 2014.
About the Author
Eve Cuny, MS
Associate Professor, Dental Practice
Director, Environmental Health and Safety
University of the Pacific
Arthur A. Dugoni School of Dentistry
San Francisco, California