Vaccines

Abstract page, Summary page, Body, about 6 paragraphs.Times Roman, Font 12

This is the chapter in my textbook, perhaps it will help.

Vaccines are drugs that are used to prevent certain contagious (easily transmitted) diseases that can be fatal or cause serious disabilities. These diseases include measles, mumps, rubella, hepatitis A, hepatitis B, diphtheria, tetanus, pertussis, influenza, pneumococcal pneumonia, meningococcal pneu-monia, and polio. This chapter discusses
The Bodys Immune Response
The immune response involves a coordinated effort between the blood and the lymphatic system to destroy microorganisms that invade the body. These microor-ganisms include bacteria, viruses, protozoa, fungi, yeasts, etc. Millions of bacteria live in the intestine and are beneficial to the body, but microorganisms that cause disease are known as pathogens. The combining form path/o-means disease and the suffix gen means that which produces; a pathogen is something that produces disease. Each type of pathogen has antigens (protein molecules on its bacterial cell wall or viral capsid/protein shell) that the immune system identifies as being for-eign to the body and something that must be destroyed. Pathogens can be present locally in the tissues at a site of entry into the body (the mouth, nose, or a break in the skin), or they can be widespread throughout the body and in the blood. Once a pathogen is detected, the body attacks it in several different ways. The next section briefly details the bodys immune response against bacteria and viruses because those pathogens are the only diseases for which vaccines are available. The body uses white blood cells (leukocytes) and antibodies (immunoglobulins)
to launch its immune response. There are five types of white blood cells: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each has a different role to play in protecting the body, but we will concentrate on the first three types as well as on antibodies.
Neutrophils engulf and destroy bacteria. Bacteria contain DNA and are able to reproduce themselves in the tissues and blood. Some bacteria also release toxins that damage body tissues.
Lymphocytes play several different roles in the immune response, mainly against viruses. Viruses only contain RNA, and so they must enter body cells in order to reproduce themselves. Special lymphocytes known as NK (natural killer) cells recognize foreign cells (a bacterium or a cell infected by a virus) even before the cell is coated with antibodies, and these lymphocytes release chemicals to destroy that bacterium or virus-infected cell. B lymphocytes (B cells) become active when a monocyte (another type of white blood cell) presents them with fragments of a bacteria or virus it has eaten. Then the B lymphocyte produces antibodies that coat that bacterium or virus-infected cell and mark it for destruction. T lympho-cytes (cytotoxic T cells) produce toxic granules to kill cells that are infected with a virus. When a T cell is exposed to a virus, it becomes a memory T cell. Memory T cells are inactive until the next time a virus enters the body; then they remember the virus and become cytotoxic T cells that kill pathogens.
Monocytes engulf and destroy bacteria and virus-infected cells that have been coated with antibodies. Then they take fragments of the pathogens they have eaten and present them to B lymphocytes and T lymphocytes. When monocytes eat virus-infected cells, they produce the substance interferon; interferon then produces an antiviral substance that keeps viruses from entering other cells and spreading throughout the body. Interferon also stimulates NK cells to attack and kill virus-infected cells even before they are coated with antibodies. Monocytes also produce tumor necrosis factor that destroys the endotoxins produced by certain gram-negative bacteria.
Antibodies (also known as immunoglobulins) are produced by B lymphocytes. There are five types of immunoglobulins, but we will concentrate on only three of them.
Immunoglobulin M (IgM) is produced the first time the body encounters a bacterium or virus.
Immunoglobulin G (IgG) is the most abundant of all of the immunoglobulins. It provides active immunity, the bodys response and defense against patho-gens it has encountered before. IgG can pass from the mothers blood through the placenta to the fetus.
Immunoglobulin A (IgA) is found in body secretions, such as tears and saliva, as well as in the mucous membranes of the nose, lungs, and intestines where pathogens first enter the body. IgA is also found in colostrum, the first milk produced by a breastfeeding mother.
Types of Immunity
Immunity is the state of the bodys own immune system being able to identify, attack, and destroy disease-causing pathogens (bacteria and viruses). This is natural immunity, a natural or innate ability of the immune system that is part of each indi-viduals genetic makeup, although its effectiveness varies from person to person. This natural immunity is in contrast to acquired immunity. Acquired immunity results from some type of exposure to a pathogen. Acquired immunity can be provided by antibodies from another source (such as from a fetus mother) or from a drug (such as an immune globulin drug), or it can be provoked by the immune systems response to a vaccine. There are four types of acquired immunity.
1. Passive immunity, naturally acquired. This is the first type of immunity that can be acquired, because it occurs when the fetus is still in the mothers uterus and continues during the first few months of a newborn babys life. Immunoglobu-lin G (IgG) antibodies in the mothers blood pass through the placenta and enter the fetal circulation. After birth, if the mother is breastfeeding, immunoglobulin A antibodies in the mothers milk (colostrum) enter the newborns blood. These antibodies circulating in the blood provide temporary immunity (for the first 18 months of life) to bacterial and viral diseases that the mother has had in the past.
2. Passive immunity, artificially acquired. This type of immunity comes from an immune globulin drug that contains immunoglobulins (antibodies) against a specific disease. This drug is given after the patient has been exposed to that disease. Examples: rabies immune globulin, hepatitis B immune globulin.
3. Active immunity, naturally acquired. This type of immunity occurs after expo-sure to a disease-causing pathogen. Exposure to diseases in the environment begins at the moment of birth, but at that time the childs naturally acquired pas-sive immunity with antibodies from the mother protect it to some extent until 18 months of age; then the child begins to produce its own antibodies. Naturally acquired active immunity begins at 18 months of age. Immunoglobulin M (IgM) antibodies are produced the very first time a new bacterium or virus enters the body. As each new pathogen is encountered, the childs maturing immune sys-tem is able to identify, attack, and destroy it. After that, immunoglobulin G (IgG) antibodies continue to provide active immunity against bacteria and viruses that the body has seen before.
4. Active immunity, artificially acquired. This type of immunity is the basis of vaccines and vaccination. The vaccine is a drug that artificially stimulates the patients immune system to develop antibodies against a disease it has never encountered. Vaccines provide active, immediate immunity to prevent a disease from ever occurring in the patient, even if the patient is later exposed to the pathogen that causes that disease.
A vaccine can be in one of several forms.
1. Live but attenuated (weakened) bacteria or viruses. This form of vaccine contains a pathogen that is grown in several different types of cultures to weaken it, or it is grown at temperatures that do not allow it to reproduce easily. The bacteria or viruses can also be subjected to target mutagenesis to create DNA/RNA mutations that further weaken the bacterium/ virus. Then, these less virulent (its ability to invade a person and produce dis-ease) strains that are weaker than the original strain are selected for the vaccine.
2. Intact but inactivated (killed) bacteria or viruses. This form of vaccine contains a pathogen that is grown in a culture and then inactivated (killed) with heat or chemicals. The bacteria or viruses are present but cannot reproduce. However, antigens on the outside surface of the bac-terium or virus are not destroyed and can still provoke a response from the patients immune system.
3. Subunits. This form of vaccine consists only of one part (a subunit) of the bacte-rium or virus, a part that contains just the antigens from its surface. These anti-gens cannot reproduce, but they can still provoke a response from the patients immune system. Example: hepatitis B surface antigen vaccine.
4. Toxoids. This form of vaccine consists only of the toxin produced by certain gram-negative bacteria. The toxin is inactivated by formaldehyde so that it can no longer cause fever and infection, but it can still provoke a response from the patients immune system. The combining form tox/o-means poison and the suf-fix oid means resembling. Toxoid vaccines resemble the poisonous endotoxin produced by the bacteria. Examples: tetanus toxoid and diphtheria toxoid.
Polysaccharide Versus Conjugate Vaccines
Polysaccharides are carbohydrate molecules found in the walls that surround certain bacteria. Although these capsules contain antigens, they do not provoke a strong immune response when these bacteria invade the body. A conjugate (joined) vaccine is one in which a polysaccharide taken from the capsule around a bacterium is joined to a protein carrier. This combination produces a longer-lasting immune response. The first conjugate vaccine was the Haemophilus influenzae type b vaccine, produced in 1987. The pneumococcal pneumonia vaccine is also a conjugate vaccine.
Valence
Vaccines that contain just a single type of antigen or a single strain of one pathogen are monovalent. Vaccines that contain three are trivalent. Vaccines that contain sev-eral strains are multivalent. Most vaccines contain several strains that are responsible for causing the majority of cases of that disease. Example: Each year, the Centers for Disease Control and Prevention (CDC) determine the most common strains of the influenza virus to include in that years flu shot. Example: Gardasil, a vaccine to prevent human papillomavirus infection, is a quadrivalent vaccine that contains four different strains of the virus. Example: One type of pneumococcal pneumonia vaccine contains 23 different strains; it is a 23-valent vaccine.
Single Versus Combined Vaccines
Single vaccines can be administered, but several vaccines are often combined into a single dose to avoid multiple injections. This is especially true for child-hood immunizations. Examples: The measles, mumps, and rubella vaccines are combined into one vaccine liquid in the trade name drug M-M-R II. The measles, mumps, rubella, and varicella (chickenpox) vaccines are combined in the trade name drug ProQuad.
Booster Shots
After the initial vaccine injection for a particular disease, the second, third, or fourth vaccine injection is known as a booster shot. It is used to boost the immune response to that disease after some time has elapsed. Example: Adults should receive a tetanus vaccine booster every 10 years.
ative thimerosal is a mercury-containing compound (50% mercury by weight). According to the FDA, thimerosal has been used since the 1930s as a preservative in many vaccines that did not contain live virus. In the 1970s, widespread mercury (methyl mercury, not thimerosal) poisoning from fungicide-treated seed grains produced neurologic damage (cerebral palsy, motor dysfunction, and developmental delays) in children but not adults. This event raised the issue of the safety of thimerosal in vaccines. In 1997, the FDA reviewed the use of thimerosal in vaccines for children and found that some vaccines could expose a child to a level of mercury that exceeded the recommended limit. The Public Health Service, the FDA, the CDC, and the National Institutes of Health recommended that thimerosal be removed from pediatric vaccines, and the drug companies did do this over time. In 2001, the Institute of Medicine (IOM) reviewed the potential link between thimerosal and neurodevelopmental disorders (attention-deficit hyper-activity disorder, speech delay) and between the measles/mumps/rubella vaccine and autism. Worldwide rates of autism increased in the 1980s and 1990s, but the IOMs research was inconclusive (no direct causal relationship was found), because exposure to thimerosal-containing vaccines was decreasing. However, the IOM did recommend removing thimerosal from vaccines as a public health goal. Accord-ing to a 2014 CDC Vaccine Fact Sheet, pediatric vaccines manufactured in the U.S. contain no thimerosal or only trace amounts. The exception is the inactivated influenza virus.
517 Immune Globulin Drugs
Immune globulins are drugs that are made by processing human blood plasma and extracting (removing) the antibodies (immunoglobulins). These immune globulin drugs are given to patients to provide short-term (temporary) protection against a disease after the patient has been exposed to that disease and does not have any anti-bodies of their own. Examples: hepatitis B immune globulin, varicella (chickenpox) immune globulin, rabies immune globulin, and tetanus immune globulin.
The Process of Immunization
Immunization is a procedure that inserts a vaccine into the body. The combining form immun/o-means immune response, and the suffix ization means process of creating. This procedure is also known as vaccination. An older word is inoculation. Prior to immunization, the patient is asked a series of questions; those questions help ensure that it is safe to give that patient a vaccination.
he routes of administration used for immunizations include the oral, intranasal, intradermal, subcutaneous, and intramuscular routes, although most immunizations are given by intramuscular injection.
The oral route is used for immunizations for adenovirus and rotavirus. Most vac-cines cannot be given orally because they are not absorbed from the intestines.
The intranasal route is used for one type of immunization for influenza. The subcutaneous route is used for immunizations for measles, mumps, rubella, varicella, and herpes zoster.
All other immunizations are given by the intramuscular route.
The U.S. Advisory Committee on Immunization Practices states that infants from newborn to 35 months should receive immunizations by intramuscular injection in the outer aspect of the thigh muscle. Children age 3 years and older, as well as adults, are given intramuscular injections in the upper arm. The muscle selected must be large enough to absorb the amount of the liquid drug and have enough bulk to it that the needle will not accidentally injure a nearby nerve. Following an immunization injection, common side effects include soreness, red-ness, or swelling at the injection site, fever, aches, headache, or fatigue, lasting one to two days. A severe reaction should be reported to the Vaccine Adverse Event Report-ing System (VAERS), sponsored by the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC).
ses Prevented by Vaccines
The immune response is an intricate and highly organized response to keep the body healthy and defend against pathogens. In most cases, the bodys immune response is sufficient to prevent widespread infection in the body. Sometimes, however, the pathogen is present in such a high concentration that it overwhelms the bodys defenses, or the pathogen is particularly virulent and is able to multiply rapidly within the body. In both instances, the bodys immune system defenses are overwhelmed. A bacterial or viral disease that causes a sudden, unexpected outbreak among many people is known as an epidemic. A pandemic is a bacterial or viral disease that has spread throughout an entire region, country, or the world. The role of vaccines and immunizations is to prevent epidemics and pandemics from occurring. Vaccines were developed because some diseases were highly contagious and posed a public health threat, or their symptoms were severe (often requiring hospi-talization), or the disease could cause permanent disability or even death. Accord-ing to the World Health Organization, vaccines are currently available to prevent 25 diseases. The most common vaccine-prevented diseases are discussed here, in alphabetical order.
Adenovirus
Adenovirus is a virus that can cause severe epidemics of respiratory illness. There are many types of adenoviruses, and the vaccine contains live adenovirus types 4 and 7. The adenovirus vaccine is given to everyone entering basic training in the military. It is approved for use only in the military. The vaccine is given orally, and it comes as two tablets that are taken at the same time. Each tablet contains one of the two types of the live virus.
adenovirus type 4 and type 7 vaccine Anthrax
Anthrax is a bacterial respiratory disease that is often fatal. It is spread by spores that can be transmitted by food or by touching infected animals or clothing. Before Louis Pasteur developed the first anthrax vaccine in 1881, anthrax killed hundreds of thou-sands of animals and humans worldwide. Terrorist attacks using powdered anthrax as a biological weapon led to a renewed interest in the vaccine. The anthrax vaccine is given to some military personnel and some persons who handle animals and animal products. This vaccine is given by intramuscular injection.
anthrax vaccine (BioThrax) Diphtheria
Diphtheria is a bacterial respiratory disease. It is highly contagious. It causes a high fever and sore throat and creates a gray membrane in the throat that can cause suf-focation. The bacterium can also cause heart and nerve damage because of a toxin it produces. Before a vaccine was available, diphtheria caused 200,000 deaths each year in the United States. The diphtheria vaccine is given to infants in four doses between ages 2 months and 18 months. This is in a combination vaccine that also includes tetanus and pertussis vaccines. This vaccine is given by intramuscular injection.
diphtheria/tetanus/pertussis (DTaP) vaccine (Adacel, Boostrix)
Haemophilus influenzae Type b (Hib) Unlike the well-known viral influenza (the flu), Haemophilus influenza is a bacterium. It causes severe pneumonia and meningitis in young children. The Hib vaccine is given to infants in four doses between ages 2 months and 15 months. This vaccine is given by intramuscular injection.
Haemophilus influenzae type b vaccine (PedvaxHIB) Hepatitis A
Hepatitis A is caused by the hepatitis A virus (HAV). It is an acute, but short-lived infection, and most patients recover completely. Hepatitis A is caused by exposure to water or food that contains the virus because it is contaminated with the feces of a person who is already infected. The vaccine was first developed for children in high-risk areas in the United States but, because this disease is so prevalent in underdeveloped countries in the world and travelers to those countries bring the disease back to the United States, the hepatitis A vaccine is now given to all children. The first dose is given between ages 12 months and 23 months. A second dose (booster shot) is given one to one and one-half years later. This vaccine contains inactivated/ killed virus, and it is given by intramuscular injection.
hepatitis A vaccine (Havrix, Vaqta) Hepatitis B
Hepatitis B is caused by the hepatitis B virus (HBV). It is an acute infection, but most patients recover completely. Other patients have a chronic infection, although they may have no symptoms. A patient with chronic hepatitis B is a carrier of the disease and can infect others. Hepatitis B is caused by exposure to the blood, saliva, or vaginal secretions of a person who is already infected. This exposure can occur from sexual activity, from drug addicts sharing needles, from healthcare workers being stuck by a contaminated needle, or from patients receiving a blood transfusion with infected blood. An infected mother can pass hepatitis B to her fetus before birth or when breastfeeding her newborn infant. Hepatitis B vaccine, which contains only antigens from the surface of the hepatitis B virus, is given to all children. The first dose is given between ages 1 and 2 months. The second dose (booster shot) is given between ages 6 months and 18 months. Because of their constant exposure to blood and body fluids, healthcare workers are vaccinated prior to employment. This vaccine is given by intramuscular injection.
hepatitis B vaccine (Engerix-B, Recombivax HB) Hepatitis B immune globulin is given after exposure to the virus (healthcare work-ers after being stuck by a used needle; babies born to women who have hepatitis B). This immune globulin drug is given by intramuscular injection.
hepatitis B immune globulin (HepaGam B) Herpes Zoster
Herpes zoster is caused by the varicella-zoster virus, the same virus that causes vari-cella (chickenpox) in childhood. After a patient recovers from chickenpox, the virus remains dormant in the body until it is triggered and reactivated by stress, illness, or a medicine. Then it forms clusters of painful vesicles (blisters) on the skin that follow the course of a particular nerve, often on the side of the body. This disease is known as shingles. The herpes zoster or shingles vaccine is given to persons 50 years of age or older who have had chickenpox in childhood and are at risk for developing shingles. This vaccine is given by subcutaneous injection.
Human Papillomavirus
Human papillomavirus (HPV) is a virus that is common in nearly all sexually active adults. There are more than 40 different strains of HPV that cause genital warts, a sexually transmitted disease. HPV also causes cervical cancer in women. This vaccine was first approved by the FDA in 2006 to prevent HPV infection and cervical cancer in women. Later, it was found that the human papillomavirus could also cause throat can-cer in a person who had oral sex with an infected partner. Since 2011, the vaccine has been recommended for girls and boys, ages 9 to 26. It is given in three doses. Cervarix is a bivalent vaccine that contains two of the strains of the virus (types 16 and 18). Gardasil is a quadrivalent vaccine that contains four of the strains of the virus (types 6, 11, 16, and 18) that cause 75% of cervical cancer, 70% of vaginal cancer, and 90% of the cases of genital warts. This vaccine is given by intramuscular injection.
Influenza
Influenza (the flu) is a viral respiratory disease that is particularly contagious. A vaccine was developed for influenza because of the severity of the illness and its worldwide spread. There are three types of the influenza virus (A, B, and C). Types A and B cause the most severe illness and are included in the influenza vaccine. Begin-ning in 2012, the CDC recommended annual influenza immunizations for all persons, beginning at 6 months of age, throughout life. The type of influenza vaccine given depends on the patients age, whether she is pregnant or not, and whether he/she is allergic to eggs. A high-dose influenza vaccine (Fluzone High-Dose) is recommended for persons age 65 and over. It contains four times the number of inactivated viruses. This higher dose is needed to adequately stimulate the weaker immune response in patients of this age. The most common route of administration is intramuscular injection. The trade name vaccine Fluzone Intradermal can be given by intradermal injection. The trade name vaccine FluMist is a live attenuated virus that is given by nasal spray (intranasal).
Measles
Measles, also known as rubella, is often thought of as a mild childhood disease with a rash. In fact, it is a highly contagious disease that is caused by a virus. It is spread by coughing, and a person can become infected just by breathing the air where someone with measles coughed two hours before. Symptoms include a high fever, a hacking cough, and a red rash. In the 1950s, measles caused 48,000 people each year to be hospitalized, 7,000 to have seizures, and 500 to die. The vaccine is given at 12 to 15 months of age and again at 4 to 6 years of age. This is a combination vaccine that also includes mumps and rubella vaccines. This vaccine is given by subcutaneous injection.
Meningococcal Meningitis Meningococcal meningitis is caused by the bacterium Neisseria meningitidis. It causes inflammation of the brain and spinal cord and can cause deafness, kidney damage, nervous system damage, and even death. This disease can kill a child in 24 hours. Adolescents between ages 11 and 12 receive the first dose, and the second at age 16. It is recommended that college freshman living in dormitories also be immunized with this vaccine. Persons older than 55 years are given a different vaccine (Menomune). This vaccine is given by intramuscular injection.
meningococcal meningitis vaccine (Menactra, Menomune, Menveo) Mumps
Mumps is a very contagious disease that causes swelling of the salivary glands, par-ticularly those in the cheeks. It is spread by coughing. Mumps can cause inflammation of the brain, deafness, and swelling of the testicles in boys. The vaccine is given at 12 to 15 months of age and again at 4 to 6 years of age. This is a combination vaccine that also includes measles and rubella vaccines. This vaccine is given by subcutane-ous injection.
measles/mumps/rubella vaccine (M-M-R II, ProQuad) Pertussis
Pertussis, or whooping cough, is a bacterial disease that causes respiratory distress and severe coughing. The cough has a characteristic choking sound from spasms of the voice box. The disease is spread by coughing and is very contagious. Half of unvaccinated babies who contract pertussis become sick enough to require hospital-ization. The pertussis vaccine is given to infants in four doses between ages 2 months and 18 months of age. This is in a combination vaccine that also includes diphtheria and tetanus vaccines. Women who are pregnant are advised to get the vaccine for themselves during the third trimester of their pregnancy. This vaccine is given by intramuscular injection.
diphtheria/tetanus/pertussis (DTaP) vaccine (Adacel, Boostrix) Pneumococcal Pneumonia
Pneumococcal pneumonia is caused by the bacterium Streptococcus pneumoniae. It is spread by droplets in the air and is the leading cause of respiratory illness in the world. It causes pneumonia, meningitis, sinusitis, and otitis media, mostly in chil-dren under age 5. Children are given the pneumococcal conjugate vaccine (PCV13) because it produces a longer-lasting immune response. (The 13 means it contains the 13 strains of pneumococcus that cause the majority of respiratory infections.) Children receive four doses between 2 months and 15 months of age. All adults age he pneumococcal polysaccharide vaccine (PPSV23), par-ticularly those in long-term care facilities. (The 23 means it contains 23 different strains.) This vaccine is given by intramuscular injection.
pneumococcal conjugate vaccine (PVC13) (Prevnar 13) pneumococcal polysaccharide vaccine (PPSV23) (Pneumovax 23)
Polio
Polio or poliomyelitis is a viral disease of the spinal cord that causes weakness of the muscles, paralysis, an inability to breathe, and even death. It is spread by infected persons through feces and contaminated water and food. In the past, those who were infected and were unable to use their paralyzed breathing muscles spent the rest of their lives in iron lung machines that breathed for them. Even those who recovered were often left with partial paralysis. Children receive four doses of killed inactivated polio virus (IPV) from 2 months to 4 years of age. This vaccine is given by subcutane-ous or intramuscular injection.
polio virus vaccine (IPOL)
Rabies
Rabies is a viral disease that is carried by dogs, cats, and other mammals (such as bats, raccoons, skunks, foxes) and is transmitted via the saliva in an animals bite. The virus causes inflammation of the brain and spinal cord, with seizures, and is fatal in both humans and animals. There is a rabies vaccine for veterinarians and those who work with animals or those who travel to countries where rabies is prevalent. About 18,000 people in the United States are bitten by an animal that might have rabies and are given the rabies immune globulin drug to provide temporary immunity. The immune globulin drug is given by subcutaneous or intramuscular injection around the area of the animal bite. The vaccine is given by intramuscular injection.
rabies immune globulin (HyperRab S/D, Imogam Rabies-HT) rabies vaccine (Imovax, RabAvert)
Rotavirus
Rotavirus (RV) is a viral illness that causes fever, vomiting, and severe diarrhea. It is a highly contagious disease. About 500,000 children worldwide die from it each year. A vaccine became available in 2006. The vaccine is given in three doses, at 2 months, 3 months, and 4 months of age. This vaccine is a liquid that is given orally.
rotavirus vaccine (Rotarix, Rota Teq) Rubella
Rubella or German measles is caused by the rubella virus and is contacted by air drop-lets from coughing. It is a relatively mild upper respiratory infection (and is known as the three-day measles), but it can cause birth defects in the fetus when the pregnant mother becomes infected, with miscarriage in 20% of the pregnancies. The vaccine is given at 12 to15 months of age and again at 4 to 6 years of age. This is a combina-tion vaccine that also includes measles and mumps vaccines. This vaccine is given by subcutaneous injection.
measles/mumps/rubella vaccine (M-M-R II, ProQuad) Tetanus
Tetanus, also known as lockjaw, is caused by the bacterium Clostridium tetani. The bacteria produce a toxin that causes muscle spasms, difficulty breathing, difficulty swallowing, and even death. The spores of this bacterium live in soil, dust, and manure. The bacteria enter the body through a skin wound, such as when a person steps on a rusty nail. The tetanus vaccine is given to infants in four doses between 2 months and 18 months of age and again at 4 to 6 years. This is in a combination vaccine that also includes the diphtheria and pertussis vaccines. This vaccine is given by intramuscular injection.
diphtheria/tetanus/pertussis (DTaP) vaccine (Adacel, Boostrix)
Varicella
Varicella or chickenpox causes a fever and an itchy rash with blisters. It is caused by the varicella-zoster virus. Although mild, it is very contagious and is spread by coughing, sneezing, sharing food, or even touching the fluid from a skin blister. The varicella vaccine is given to children between 12 and 15 months of age. This vaccine is given by subcutaneous injection.
varicella vaccine (Varivax) Other Vaccines Human Immunodeficiency Virus
In 1988, the National Institutes of Health began efforts to develop a vaccine to pre-vent HIV/AIDS. A vaccine for HIV is difficult to develop, however, because HIV is a complex virus that mutates often. Much research is still being conducted because this disease is a serious public health issue. About 50,000 Americans and 2.3 million people worldwide become HIV positive each year.
Cancer Vaccine
The only cancer vaccine now in existence is designed to treat (not prevent) male patients who already have cancer of the prostate gland. Because cancer cells are a patients own cells that have become abnormal, each type of prostate cancer can be different. This vaccine is created by collecting 50 million of the cancer patients own lymphocytes and combining them with a protein that is similar to the antigen on the cell membrane of prostate cancer cells. This vaccine is known as an autologous cellular immunotherapy drug. Autologous means pertaining to the study of the self (the patients own cells). This vaccine is given intravenously in three doses, several weeks apart, and costs $93,000. It extends the life span of patients with advanced prostate cancer by about four months. In 2010, this drug became the first cancer vaccine approved for use in the United States. This vaccine is given by the intrave-nous route.
sipuleucel-T (Provenge)
Childhood and Adult Immunization Schedules
Recommended immunization schedules are published by the Centers for Disease Control and Prevention (CDC) in cooperation with the American Academy of Pediat-rics and the American Academy of Family Physicians.

Last Completed Projects