Vaccines - VOICES FOR VACCINES

Vaccines

People of all ages should stay current on their vaccinations. The World Health Organization indexes vaccine recommendations for countries around the world. Specific information about U.S. standard and travel vaccines, as well as precautions and contraindications to vaccination, are available from the Centers for Disease Control and Prevention. The U.S. vaccination schedule is established by the Advisory Committee on Immunization Practices and endorsed by the American Academy of Pediatrics, the American Academy of Family Physicians, and the American College of Physicians.

In addition to the links below, for further information we recommend the American Academy of Pediatrics (AAP), the University of Pennsylvania Vaccine Ethics Project, and PATH.

Anthrax

Infectious Agent:	Bacillus anthracis
Mode of Transmission:	Animals are the natural reservoir; bacterial spores can live in soil or in animal products such as wool.
Clinical Manifestations:	Cutaneous anthrax causes painless blistering and ulceration. Gastrointestinal anthrax causes nausea, loss of appetite, bloody diarrhea, fever, and stomach pain. Inhalational anthrax causes sore throat, fever, muscle aches, cough, and other cold-like symptoms.
Outcomes:	Skin infections are treatable, but infections of the respiratory or digestive tracts are often fatal.
More Information:	CDC, IAC, VEC, NNii

Bacterial Meningitis

Infectious Agent:	Vaccines are available against the major causes of bacterial meningitis: Haemophilus influenzae type b (Hib); Neisseria meningitidis serogroups A, C, W-135, and Y; and the most pathogenic serotypes of Streptococcus pneumoniae (pneumococcus).
Mode of Transmission:	Exposure to respiratory secretions of infected persons via coughing or sneezing.
Clinical Manifestations:	Meningitis is characterized by sudden fever, stiff neck or back, vomiting, and lethargy. All three bacteria can also cause sepsis (blood infection) and pneumonia; in addition, Hib can cause epiglottitis and serious skin infections.
Outcomes:	Hib meningitis is fatal in about 5% of patients and causes brain damage in 10-30% of survivors. The fatality rate for N. meningitidis is about 10%; many survivors suffer long-term sequelae, including loss of limbs. About 30% of those with pneumococcal meningitis die of the disease.
More Information:	Hib: WHO, CDC, IAC, VEC, NNii N. meningitidis: WHO, CDC, IAC, VEC, NNii S. pneumoniae: WHO, CDC, IAC (children), IAC (adults), VEC, NNii

Cholera

Infectious Agent:	Vibrio cholerae (a bacterium)
Mode of Transmission:	Food or water contaminated with feces of infected persons.
Clinical Manifestations:	Diarrhea, vomiting, leg cramps.
Outcomes:	Some strains produce only mild diarrhea, but others can cause death within hours if untreated.
More Information:	CDC, VEC

Diphtheria

Infectious Agent:	Corynebacterium diphtheriae
Mode of Transmission:	Exposure to respiratory secretions of an infected person via coughing or sneezing
Clinical Manifestations:	Sore throat, fever; may progress to airway obstruction and coma
Outcomes:	Airway obstruction may result in coma or death. Diphtheria toxin can also cause myocarditis or neuropathy.
More Information:	WHO, CDC, IAC, VEC, NNii

Hepatitis A

Infectious Agent:	Hepatitis A virus
Mode of Transmission:	Ingestion of infected feces, usually facilitated by contaminated food or water.
Clinical Manifestations:	Fever, malaise, loss of appetite, jaundice, nausea. Adults are more severely affected than children, whose infections may be asymptomatic.
Outcomes:	Illness may persist for weeks or months, but fatalities are unusual.
More Information:	WHO, CDC, IAC, VEC, NNii

Hepatitis B

Infectious Agent:	Hepatitis B virus
Mode of Transmission:	Exposure to blood, saliva, or other body tissues or fluids
Clinical Manifestations:	Loss of appetite, vague abdominal discomfort, nausea, vomiting, rash, and jaundice. Most often asymptomatic at first, especially in children.
Outcomes:	About 1% of cases are fatal. Most infants who acquire the virus via childbirth will be chronically infected and have a 15-25% chance of premature death from cirrhosis or liver cancer. Pregnant women are at increased risk of fulminant disease.
More Information:	WHO, CDC, IAC, VEC, NNii

Herpes Zoster (Shingles)

Infectious Agent:	Varicella-zoster virus
Mode of Transmission:	Disease results from reactivation of latent infection of the nervous system.
Clinical Manifestations:	Extremely painful, blistered rash.
Outcomes:	Rash can leave permanent neurological damage.Pain can persist for weeks or months after the rash heals.
More Information:	CDC, IAC, VEC, NNii

Human Papillomavirus (HPV)

Infectious Agent:	Human papillomavirus
Mode of Transmission:	Direct contact
Clinical Manifestations:	Warts on infected tissue
Outcomes:	A few of the many strains of human papillomavirus can cause cancer of the cervix or other sites which are infected with the virus.
More Information:	WHO, CDC, IAC, VEC, NNii

Influenza

Infectious Agent:	Influenza virus
Mode of Transmission:	Respiratory secretions from an infected person
Clinical Manifestations:	Sudden onset of fever, headache, fatigue, and cold symptoms
Outcomes:	Fatality rate is generally low but higher among the elderly and those with underlying medical conditions.
More Information:	WHO, CDC, IAC, VEC, NNii

Japanese Encephalitis

Infectious Agent:	Japanese encephalitis virus
Mode of Transmission:	Bite of an infected mosquito.
Clinical Manifestations:	Encephalitis is characterized by fever, headache, stiff neck, nausea, vomiting
Outcomes:	Severity varies greatly; infants are the most likely to experience neurological sequelae.
More Information:	CDC, VEC

Measles

Infectious Agent:	Measles virus
Mode of Transmission:	Respiratory secretions from an infected person.
Clinical Manifestations:	Rash, cough, runny nose, red and watery eyes followed by high fever and rash.
Outcomes:	Complications may include pneumonia, diarrhea, encephalitis, and severe skin infections. Fatalities are rare in the developed world, but in Africa, measles kills nearly half a million children annually.
More Information:	WHO, CDC, IAC, VEC, NNii

Mumps

Infectious Agent:	Mumps virus
Mode of Transmission:	Respiratory secretions from an infected person.
Clinical Manifestations:	Fever, headache, tiredness, swelling of parotid salivary gland
Outcomes:	Complications include meningitis and loss of hearing; postpubertal males may experience orchitis.
More Information:	WHO, CDC, IAC, VEC, NNii

Pertussis (Whooping Cough)

Infectious Agent:	Bordetella pertussis, a bacterium
Mode of Transmission:	Respiratory secretions from an infected person.
Clinical Manifestations:	Episodes of severe coughing that may persist for weeks. Coughing may be severe enough to induce vomiting, cyanosis, or loss of consciousness.
Outcomes:	Most pertussis deaths are in infants younger than 6 months of age.
More Information:	WHO, CDC, IAC, VEC, NNii

Plague

Infectious Agent:	Yersinia pestis, a bacterium
Mode of Transmission:	Bites of infected fleas usually carried into homes by rodents; cats and rabbits can also serve as vectors. May also be transmitted by respiratory secretions from an infected person.
Clinical Manifestations:	Swelling and pain in lymph nodes near site of the bite; high fever, chills, headache.
Outcomes:	May develop pneumonia and/or septicemia that can be fatal.
More Information:	CDC

Poliomyelitis

Infectious Agent:	Poliovirus
Mode of Transmission:	Primarily person-to-person via exposure to feces.
Clinical Manifestations:	Initial infection may be inapparent or cause mild fever, headache, nausea, and vomiting. Infection that spreads to the nervous system causes paralytic poliomyelitis – varying degrees of temporary or permanent paralysis.
Outcomes:	Paralytic poliomyelitis can be fatal. Survivors may experience post-polio syndrome later in life, with muscle weakness and pain.
More Information:	WHO, CDC, IAC, VEC, NNii

Q Fever

Infectious Agent:	Coxiella burnetii, a bacterium
Mode of Transmission:	Direct contact with infected sheep, cattle, goats, or other domestic and wild animals; organism can also travel long distances through the air.
Clinical Manifestations:	Chills, headache, general malaise
Outcomes:	Infection may become chronic, mainly affecting the endocardium, but is rarely fatal.
More Information:	CDC

Rabies

Infectious Agent:	Rabies virus
Mode of Transmission:	Bite of an infected animal, such as a fox, skunk, raccoon or bat.
Clinical Manifestations:	Headache, fever, and malaise, progressing to delirium, and convulsions
Outcomes:	After symptoms develop, rabies is almost always fatal if untreated; vaccine is effective if given after exposure but before onset of symptoms.
More Information:	CDC, IAC, VEC, NNii

Rotaviral Gastroenteritis

Infectious Agent:	Rotavirus
Mode of Transmission:	Fecal-oral route; virus can persist for long periods on hard surfaces or in water.
Clinical Manifestations:	Fever, vomiting, diarrhea
Outcomes:	Can cause fatal dehydration, particularly in infants; responsible for several hundred thousand deaths annually in the developing world.
More Information:	WHO, CDC, IAC, VEC, NNii

Rubella

Infectious Agent:	Rubella virus
Mode of Transmission:	Respiratory secretions of an infected person.
Clinical Manifestations:	Mild rash; many cases are subclinical
Outcomes:	Infection during the first trimester of pregnancy often leads to severe birth defects, mental retardation or intrauterine death.
More Information:	WHO, CDC, IAC, VEC, NNii

Smallpox

Infectious Agent:	Variola virus
Mode of Transmission:	Eradicated from natural circulation in 1977, but laboratory specimens still exist. Transmitted from person to person through direct contact or by exposure to respiratory secretions.
Clinical Manifestations:	Fever, malaise, infective rash with pustules on the skin
Outcomes:	Fatal in up to 30% of infected persons.
More Information:	CDC, IAC, NNii

Tetanus

Infectious Agent:	Clostridium tetani
Mode of Transmission:	Introduction of the bacterium into a puncture wound or, less commonly, through injection of contaminated street drugs or unhygienic surgical practices.
Clinical Manifestations:	The toxin secreted by the bacterium causes painful, progressively more severe muscular spasms
Outcomes:	Most likely to be fatal in the very young and old
More Information:	WHO (neonatal), WHO (general), CDC, IAC, VEC, NNii

Tuberculosis

Infectious Agent:	Mycobacterium tuberculosis
Mode of Transmission:	Respiratory secretions and airborne droplets of an infected person.
Clinical Manifestations:	Initial infection is usually asymptomatic, but leads to active disease in about 10% of those infected; infants and immunosuppressed individuals are at elevated risk. Disease is primarily pulmonary but can also affect the lymph nodes, pericardium, and other sites.
Outcomes:	About 65% of pulmonary cases are fatal within 5 years if not treated.
More Information:	WHO, CDC, VEC, NNii

Typhoid Fever

Infectious Agent:	Salmonella typhi
Mode of Transmission:	Exposure to food or water contaminated with feces or urine of infected persons
Clinical Manifestations:	Fever, headache, bradycardia, skin markings, digestive disturbance
Outcomes:	Severe cases may be fatal if untreated; about 500,000 deaths annually, mainly in the developing world.
More Information:	CDC, VEC, NNii

Varicella (Chickenpox)

Infectious Agent:	Varicella-zoster virus
Mode of Transmission:	Respiratory secretions of an infected person or with vesicular fluid from a varicella lesion.
Clinical Manifestations:	Skin rash with blister-like sessions; sometimes fever.
Outcomes:	Generally mild in healthy children. May be severe or fatal among adults and immunocompromised persons. Latent infection can reappear as herpes zoster (shingles).
More Information:	WHO, CDC, IAC, VEC, NNii

Yellow Fever

Infectious Agent:	Yellow fever virus
Mode of Transmission:	Bite of an infected mosquito.
Clinical Manifestations:	Mild fever, headache, jaundice, vomiting; some cases appear to remit and then progress to a phase that includes bleeding from the nose, gums, and gastrointestinal tract.
Outcomes:	About 5% fatal
More Information:	WHO, CDC, VEC, NNii