15 vaccine preventable childhood diseases

1. Vaccine preventable childhood
diseases

2. Modes of action of vaccines for childhood diseases.
• Active Immunity:
• Active immunity is induced by vaccines that contain weakened or
inactivated pathogens, their toxins, or specific components of the
pathogen. These vaccines stimulate the immune system to produce a
targeted immune response, resulting in long-lasting protection against
subsequent exposure to the pathogen.
• Passive Immunity:
• Passive immunity is achieved by administering preformed antibodies or
immune cells to an individual. This immediate protection is temporary and
does not induce long-term immunity. Passive immunity is commonly used
for infants and individuals with compromised immune systems.

3. I. Measles
• Measles is a highly contagious viral illness caused by the
Measles morbillivirus..
• It is one of the leading causes of vaccine-preventable
deaths in children worldwide.
• Symptoms include high fever, rash, cough, runny nose,
and red, watery eyes.
• The measles vaccine is administered as part of the
measles-mumps-rubella (MMR) vaccine.
• The first dose, containing live attenuated virus, is typically
given at 12-15 months of age.
• A second dose is administered at 4-6 years to ensure
long-term immunity.
• The vaccine provides immunity by stimulating the
immune system to produce antibodies against the
measles virus.

4. II. Mumps (Epidemic Parotitis):
• Mumps is a viral infection caused by the mumps virus.
• It primarily affects the salivary glands, leading to painful
swelling.
• Symptoms include swollen and painful salivary glands,
fever, headache, and fatigue.
• The mumps vaccine is given as part of the MMR
vaccine.
• The first dose, containing live attenuated virus, is
usually administered at 12-15 months of age.
• A second dose is given at 4-6 years to enhance long-
term immunity.
• The vaccine stimulates the production of antibodies
against the mumps virus, providing protection.

5. III. Rubella (German Measles):
• Rubella is a viral infection caused by the rubella
virus.
• It causes a mild rash, fever, and swollen lymph
nodes.
• While usually mild, rubella can cause serious birth
defects if contracted during pregnancy.
• The rubella vaccine is included in the MMR vaccine
to prevent congenital rubella syndrome.
• The MMR vaccine, containing live attenuated
viruses, is typically administered at 12-15 months
of age.
• A second dose is given at 4-6 years to ensure long-
term immunity.
• The vaccine stimulates the immune system to
produce antibodies against the rubella virus,
providing protection.

6. IV. Pertussis (Whooping Cough)
• Pertussis is a highly contagious bacterial infection caused by Bordetella pertussis.
• It causes severe coughing spells, whooping sound, and difficulty breathing.
• Infants are at the highest risk of severe complications and death.
• Pertussis can cause episodes of apnea, where breathing temporarily stops, leading to a lack of
oxygen supply to the body. This can result in cyanosis, a bluish discoloration of the skin and
mucous membranes due to inadequate oxygenation
• Vaccination against pertussis is included in the diphtheria-tetanus-pertussis (DTaP) vaccine series.
• The DTaP vaccine, containing inactivated bacterial components, is given in a series of doses.
• The primary series consists of doses at 2, 4, 6, and 15-18 months of age.
• A booster dose is given at 4-6 years to maintain immunity.
• The vaccine stimulates the production of antibodies against B. pertussis, providing protection.

7. v. Polio (Poliomyelitis)
• Polio is a viral infection caused by the poliovirus.
• It spreads through contaminated food, water, or
direct contact with an infected person.
• The polio vaccine is administered as inactivated
poliovirus vaccine (IPV) or oral poliovirus vaccine
(OPV).
• IPV, containing inactivated poliovirus, is given in
a series of doses at 2, 4, and 6-18 months.
• A booster dose is administered at 4-6 years to
enhance long-term immunity.
• The vaccine induces the production of
antibodies, providing protection against
poliovirus.

8. VI. Hepatitis B
• a viral infection caused by the hepatitis B
virus.
• It affects the liver and can lead to chronic
liver disease and liver cancer.
• The hepatitis B vaccine contains viral
surface antigens and is given as part of
routine immunization.
• The vaccine is usually administered as a
series of doses, starting shortly after
birth.
• The exact dosing schedule may vary
depending on the specific vaccine used.
• The vaccine stimulates the immune
system to produce antibodies against the
hepatitis B virus.

9. VII. Pneumococcal Disease:
• Pneumococcal disease is caused by Streptococcus pneumoniae bacteria.
• It can result in pneumonia, meningitis, and bloodstream infections.
• Vaccination with pneumococcal conjugate vaccine (PCV) and pneumococcal
polysaccharide vaccine (PPSV) is used to prevent this disease.
• The PCV vaccine is typically administered in a series of doses at 2, 4, 6, and 12-15
months of age.
• The PPSV vaccine is usually given to older children or individuals at high risk.
• PCV provides immunity against the most common serotypes responsible for
disease, while PPSV provides broader coverage against a wider range of
serotypes.
• Depending on the specific vaccine schedule and risk factors, a booster dose of
PCV or PPSV may be recommended.

10. VIII. Rotavirus:
• Rotavirus is a highly contagious viral infection that
causes severe diarrhea, vomiting, and dehydration,
particularly in infants and young children.
• Vaccination against rotavirus has been successful in
reducing the burden of rotavirus gastroenteritis.
• There are oral vaccines available to prevent rotavirus
infection.
• The vaccine is given in a series of doses, with the first
dose usually administered at 2 months of age.
• Additional doses are given at 4 months and 6
months.
• The vaccine stimulates the immune system to
produce antibodies against the rotavirus.

11. IX. Hepatitis A
• Hepatitis A is a viral infection affecting the liver, typically spread through
contaminated food or water.
• Symptoms may include fatigue, nausea, abdominal pain, and jaundice.
• Vaccination against hepatitis A is recommended for children in areas with
high disease prevalence or individuals at increased risk.
• The hepatitis A vaccine is administered as a two-dose series.
• The first dose is given at 12-23 months of age, and the second dose is
administered 6-18 months later.
• The vaccine stimulates the immune system to produce antibodies against
the hepatitis A virus.

12. X. Influenza (Flu):
• Influenza is a viral respiratory illness that causes fever, cough, sore throat,
runny or stuffy nose, body aches, and fatigue.
• Children, especially young ones, are susceptible to severe complications
from the flu.
• Annual vaccination against influenza is recommended for all children aged
6 months and older.
• The flu vaccine formulation is updated each year to provide protection
against the most prevalent circulating strains.
• Depending on the child's vaccination history and age, one or two doses
may be recommended.
• A booster dose may be required in the first year for some children to
establish optimal immunity.

13. XI. Tetanus:
• Tetanus is a bacterial infection caused by Clostridium tetani.
• This bacterium enters the body through wounds or cuts and produces a
toxin that affects the nervous system
• The infection eventually spreads to the rest of the body where it causes
severe muscle stiffness and spasms
• can affect the ability to breathe and is life-threatening.
• Vaccination against tetanus is typically included in the diphtheria-tetanus-
pertussis (DTaP) vaccine series.
• The primary series consists of five doses given at 2, 4, 6, and 15-18 months
and 4-6 years of age.
• Booster doses, known as Tdap or Td vaccines, are recommended in
adolescence and adulthood to maintain immunity.
• The vaccine is also given at pregnancy to prevent congenital transmission.

14. XII. Varicella (Chickenpox):
• Varicella, commonly known as chickenpox, is a highly
contagious viral infection caused by the varicella-zoster
virus.
• It is characterized by an itchy rash, fever, and general
discomfort.
• Complications can arise, especially in older children
and adults.
• Vaccination against varicella is recommended to
prevent the disease and its complications.
• The varicella vaccine is typically given as two doses.
• The first dose is administered at 12-15 months, and the
second dose is given at 4-6 years of age.
• The vaccine stimulates the immune system to produce
antibodies against the varicella-zoster virus.

15. XIII. Tuberculosis (TB):
• TB is a bacterial infection primarily affecting the lungs, caused by Mycobacterium
tuberculosis.
• BCG (Bacillus Calmette-Guérin) is a vaccine used to protect against tuberculosis.
• BCG vaccination is recommended in areas where TB is endemic or for individuals
at high risk of exposure or severe TB disease.
• It is typically given shortly after birth, usually within the first few days or months.
• BCG vaccination can cause a localized skin reaction at the injection site, resulting
in a small raised bump or sore that eventually heals.
• The vaccine provides variable and partial protection against severe forms of TB,
such as disseminated or meningeal TB.
• BCG vaccination does not provide lifelong immunity, and additional measures,
such as regular TB screening, may be necessary in high-risk individuals.
•

16. XIV. Diphtheria
• Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae.
• It affects the respiratory system and can lead to severe complications,
including breathing difficulties and heart problems.
• The diphtheria vaccine is typically administered as part of the diphtheria-
tetanus-pertussis (DTaP) vaccine series:
• Mode of Action: The DTaP vaccine contains inactivated diphtheria toxoid,
which is a modified form of the toxin produced by C. diphtheriae. Upon
vaccination, the immune system recognizes the toxoid and produces
antibodies that neutralize the diphtheria toxin. These antibodies protect
against diphtheria by preventing the toxin from causing harm.

17. XV. Haemophilus influenzae type b (Hib) Disease:
• Haemophilus influenzae type b (Hib) is a bacterium that can cause severe
invasive diseases, including meningitis, pneumonia, and bloodstream
infections, primarily affecting young children.
• The Hib vaccine is administered as part of the routine childhood
immunization schedule:
• Mode of Action: The Hib conjugate vaccine contains a polysaccharide
component of the Haemophilus influenzae type b bacterium, conjugated
with a protein carrier. Upon vaccination, the immune system recognizes the
polysaccharide component and produces antibodies that specifically target
the bacteria. These antibodies help prevent invasive Hib disease by
neutralizing the bacteria and enhancing immune clearance.

18. Assignment
Question :
1. Discuss the routine childhood immunization program schedules in
Kenya.
2. Discuss the Kenyan national strategies to ensure universal
vaccination of children.