Community Health study notes

1. CHAPTER SEVEN
IMMUNIZATION:
Objectives:
At the end of the chapter, the student should be able to:
1.Learn the different types of vaccines.
2.Define immunization.
3.Name the specific vaccines that are available.
4.Understand the immunization schedule in Kenya.
5.Understand the different vaccines required when travelling to East Africa.
Introduction:
Immunization is the process whereby a person is made immune or resistant to an
infectious disease, typically by the administration of a vaccine. Vaccines stimulate the
body’s own immune system to protect the person against subsequent infection or disease.
Immunization is a proven tool for controlling and eliminating life-threatening infectious
diseases and is estimated to avert over 2 million deaths each year. It is one of the most
cost-effective health investments, with proven strategies that make it accessible to even
the most hard-to-reach and vulnerable populations. It has clearly defined target groups;
it can be delivered effectively through outreach activities; and vaccination does not require
any major lifestyle change.
Types of Vaccines
Vaccines are of two general types:
 In live attenuated vaccines, the organism in the vaccine is alive but unable to infect
a person with a normal immune system. Patients with impaired immunity-such as
those with immune deficiencies, on chemotherapy for cancer, or with AIDS-and
pregnant women must not be given live vaccines. Examples of live attenuated
vaccines are measles, mumps, rubella, and oral polio.
 Inactivated or killed vaccines contain dead, but intact, organisms, so the immune
system can still recognize them. Most vaccines are inactivated.
Vaccines are usually given at multiple intervals because the immune system needs several
reminders to “boost” immunity. Specific vaccines are available forthe following infections:
 Diphtheria
Disease: Diphtheria is a bacterial illness acquired through inhalation of infected particles.
It causes a severe sore throat and possibly heart and nerve damage. The bacteria live in
the airways of healthy or recovering humans.
Vaccine: DTP
Interval: 2-, 4-, 6-, and 15 months and 5 years of age.
Pertussis
Disease: A bacterial illness acquired through inhalation of the infected particles. It causes
severe, life-threatening coughing spells (whooping cough), and possibly seizures and brain
damage. The bacteria usually live in the airways of adults with no or minimal cough.
Vaccine: DTP
Interval: 2-, 4-, 6-, and 15 months and 5 years of age.
Tetanus

2. Disease: Tetanus is a bacterial infection acquired through dirty wound infection. Tetanus
causes severe and painful muscle contractions. The bacteria are abundant in the soil.
Vaccine: DTP
Interval: 2-, 4-, 6-, and 15 months, 5 years of age. The vaccine must be repeated every
10 years.
 Polio
Disease: Polio is a viral infection involving the mouth and throat, and later the blood and
spinal cord. Approximately 10% of the infected people develop spinal cord infection,
causing muscle paralysis, usually one-sided.
Vaccine: OPV (oral=live) and Injected (inactivated); inactivated vaccine is
given to children with immunodeficiencies.
Interval: 2-, 4-, 6-, and 18 months and 5 years of age.
 Measles
Disease: Measles is a viral infection acquired through breathing infected particles. It
causes rash, croupy cough, pneumonia, diarrhea, and possibly brain infection and
bleeding.
Vaccine: MMR
Interval: 15 months and 12 years.
 Mumps
Disease: Mumps is a viral infection acquired through breathing infected particles. It
causes painful swelling of the Parotid gland, testes, and pancreas gland.
Vaccine: MMR
Interval: 15 months and 12 years.
 Rubella (German Measles)
Disease: Rubella is a viral infection acquired through inhalation of infected particles. It
causes rash, fevers, and enlarged lymph nodes. If a pregnant woman becomes infected,
the fetus could be severely and permanently damaged.
Vaccine: MMR
Interval: 15 months and 12 years.
 Haemophilis influenza type b (Hib)
Disease: Haemophilis influenza type b is a bacterial infection acquired through inhalation
of infected particles or through contact with infected objects. It causes life-threatening
conditions such as meningitis (infection of the lining of the brain), throat swelling, and
joint infection.
Vaccine: Hib
Interval: 2-, 4-, 6-, and 15 months
 Influenza Virus
Disease: Influenza is a viral infection of the upper- and lower respiratory tract. It can be
fatal in people with heart, lung, and other chronic diseases.
Vaccine: Flu shot; recommended for patients with heart and lung disease and residents
of nursing homes and long-term care facilities.
Interval: yearly
 Pneumococcal pneumonia

3. Disease: Pneumococcal pneumonia is a bacterial illness causing pneumonia.
Vaccine: Pneumococcal vaccine; recommended for people with heart, lung, or other
chronic illnesses.
Interval: Every ten years.
Also available, based on specific circumstances, are vaccines for the following:
 Varicella-Zoster (Chickenpox): Varicella-Zoster is a viral infection acquired
through inhalation of infected particles. It causes painful blistering and later crusty
rash and fevers. Rare complications include infections of the brain, joints, and
kidneys and/or hemorrhaging. Vaccination is recommended for children with
immunodeficiencies, but it is safe and frequently given to healthy children.
 Hepatitis B: Hepatitis B is a viral infection of the liver. It is acquired through
exposure to blood (such as in a transfusion), through sexual intercourse, and from
a mother to her fetus. Vaccination is recommended in high-risk patients, especially
the health care providers.
 Cholera: Cholera is a bacterial infection of the small intestine. It causes severe
watery diarrhea and dehydration that could lead to death. The vaccine is
recommended for travelers to Africa, Middle East, and the Far East.
 Plague: Plague is a bacterial infection carried by rodents. It causes fever, skin
sores, enlarged lymph nodes, and if not treated, death. Humans are accidentally
infected by fleas that feed off the infected rodents. The vaccine is recommended for
people traveling to or working in areas where plague is prevalent.
 Typhoid fever: Typhoid is a bacterial infection caused by Salmonella. It causes
diarrhea, fevers, and if left untreated, death. The vaccine is recommended for
travelers to Africa, South America, the Middle East, and the Far East.
 Rabies: Rabies is a viral infection acquired through the bite of an infected mammal.
It causes fevers, headaches, restlessness, seizures, coma, and death. Immunization
is passive by injection of anti-Rabies antibodies.
 Lyme Disease: Lyme Disease is a bacterial infection acquired through the bite of a
tick that feeds on deer. It causes rash, fever, and, left untreated, possible
neurological or heart damage. Vaccination is recommended to those who live in
areas where deer population is large and in contact with the human population.
The following vaccines may be recommended when one is travelling to East Africa.
 Hepatitis A or immune globulin (IG). Transmission of hepatitis A virus can occur
through direct person-to-person contact; through exposure to contaminated water,
ice, or shellfish harvested in contaminated water; or from fruits, vegetables, orother
foods that are eaten uncooked and that were contaminated during harvesting or
subsequent handling.
 Hepatitis B, especially if you might be exposed to blood or body fluids (for example,
health-care workers), have sexual contact with the local population, or be exposed
through medical treatment. Hepatitis B vaccine is now recommended for all infants
and for children ages 11–12 years who did not receive the series as infants.
 Meningococcal (meningitis) if you plan to visit countries in this region that
experience epidemics of meningococcal disease during December through June.

4.  Rabies, pre-exposure vaccination, if you might have extensive unprotected outdoor
exposure in rural areas, such as might occur during camping, hiking, or bicycling,
or engaging in certain occupational activities.
 Typhoid vaccine. Typhoid fever can be contracted through contaminated drinking
water or food, or by eating food or drinking beverages that have been handled by a
person who is infected. Large outbreaks are most often related to fecal
contamination of water supplies or foods sold by street vendors
 As needed, booster doses for tetanus-diphtheria, measles, and a one-time dose of
polio vaccine for adults.
Summary of immunization schedule in Kenya:
Vaccine Age of administration
BCG At birth
OPV At birth,6wk,10wk,14wk
DPT-Hep B-Hib 6wk,10wk,14wk
Measles 9months
Yellow fever 9 months
TT Given in pregnancy under the 5TT
schedule.
Vitamin A 6m,12m,18m,24m,30m,36m,42m,
48m.Also given to mothers within
six weeks after delivery.
Revision questions
1.Describe the different types of vaccines.
2.Define immunization.
3.State four vaccines available in Kenya.
4.Describe the immunization schedule in Kenya.