Immunisation & Under 5 Card

Question 1

what are the types of immunization?

Answer 1

Active immunization: with live vaccines and non-live vaccines.
 Passive immunization

Question 2

what is active immunization?

Answer 2

Involves induction of long-term immunity through exposure to live attenuated or
killed (inactivated) infectious agents

Question 3

differentiate between live and non-live vaccines

Answer 3

Live vaccines induce long-lasting immunity but carry the risk of vaccine associated disease in the recipient or secondary host. These should be avoided in patients with compromised immunity e.g. cancer, congenital or drug induced immunodeficiency
 Non-live vaccines are not infectious and tend to induce immunity for shorter periods, thus requiring booster immunizations

Question 4

list examples of live vaccines

Answer 4

 Examples: Oral polio (OPV), varicella and Mumps, Measles and Rubella (MMR) vaccines

Question 5

list examples of non-live vaccines

Answer 5

 Examples: diphtheria, tetanus and acellular pertussis (DTaP), hepatitis A and B, inactivated polio (IPV), Haemophilus influenzae type b (HIB), influenza, pneumococcal and meningococcal vaccines

Question 6

what is passive immunization?

Answer 6

Involves delivery of preformed antibodies to individuals who have no active immunity against a particular disease but who have either been exposed to or are at high risk for exposure to the infectious agent.

Question 7

give examples of passive immunization

Answer 7

Varicella zoster immune globulin (VZIG) for immunocompromised patients who have been exposed to varicella and are at high risk for severe varicella infection.
 Newborns born to hepatitis B-positive mothers receive hepatitis B immune globulin at birth
 Visitors to high risk areas may receive hepatitis A Ig before travel

Question 8

outline the timing and route of administration of BCG vaccine

Answer 8

Timing of vaccination (in Zambia):
 At birth
 If no scar repeat dose at 12 weeks (3 months) unless in symptomatic HIV
 It is given intradermally usually on the left upper arm

Question 9

what is the purpose of the BCG vaccine?

Answer 9

 Rationale for Vaccine: protection against severe forms of TB e.g. TB meningitis
 It is not given to immunosuppressed people and individuals with active disease.

Question 10

what is the rationale of the polio vaccine

Answer 10

 Rational for vaccine: Poliovirus is an enterovirus with propensity for the CNS causing transient or permanent paresis of the extremities and meningoencephalitis

Question 11

compare the advantages and disadvantages of the types of polio vaccines

Answer 11

There are 2 types of vaccines
 Live attenuated (OPV-SABIN), administered orally
o Advantages: induction of both host immunity and secondary immunity because it is excreted in the stool of the recipient and may infect and thus immunize, close contacts (i.e. herd immunity)
o Disadvantages: possibility of vaccine related polio in host as well as unimmunized contacts.
 Non-live or inactivated (IPV-SALK), administered subcutaneously or intramuscularly, has the advantage of no vaccine-related polio but the disadvantage of not inducing secondary immunity

Question 12

outline the timing of the polio vaccine

Answer 12

 Timing of vaccination (in Zambia):
 At birth to 13 days: OPV0
 At 6 weeks: OPV 1
 After at least 4 weeks of OPV1: OPV2
 After at least 4 weeks of OPV 2: OPV3
 OPV 4 is given at 9 months only if OPV 0 was not given

Question 13

what is the rationale for the pneumococcal vaccines?

Answer 13

Rational for vaccine: Pneumococcus (Streptococcus pneumoniae) is the most common cause of acute otitis media and invasive bacterial infections in children younger than 3 years of age

Question 14

outline the timing and route of administration of the pneumococcal vaccines

Answer 14

Timing of vaccination (in Zambia):
 At 6 weeks: PCV 1
 After 4 weeks of PCV 1: PCV 2
 After 4 weeks of PCV 2: PCV 3
 The preferred site for infants and young children is intramuscular in the vastus lateralis muscle in the anterolateral thigh. The preferred injection site in older children and adults is the deltoid muscle.

Question 15

what are the advantages, disadvantages and indications of the types of pneumococcal vaccines?

Answer 15

 There are 2 types of vaccines:
 Pneumovax: composed of polysaccharide capsular antigens from 23 pneumococcal serotypes.
o Advantages: vaccine contains antigens from pneumococcal strains causing almost all cases of bacteremia and meningitis during childhood.
o Disadvantages: little immunogenicity in children younger than 2 years.
o Indications: older children and adults at high risk for pneumococcal disease (e.g. patients with sickle cell anemia who are functionally asplenic, immunodeficiency, chronic liver disease and nephrotic syndrome, and patients with anatomic asplenia)
 Prevnar: composed of 7 pneumococcal serotypes
o Advantages: immunogenicity and efficacy in preventing meningitis, pneumonia, bacteremia and otitis media from the most common pneumococcal strains in children younger than 2 years of age.
o Disadvantages: does not confer as broad coverage against pneumococcal strains as Pneumovax.
o Indication: all children younger than 2 years of age and selected children older than 2 years of age who are at high risk for pneumococcal disease

Question 16

outline the rationale for the DPT-HepB-HiB vaccines

Answer 16

 Rationale for vaccine:
 Diphtheria, tetanus and pertussis all may cause serious disease, especially in young infants.
 Hepatitis B infects 300 million worldwide.
 H. influenza type B was a serious cause of invasive bacterial infection, including meningitis, epiglottitis and sepsis before vaccine licensure in 1985. Since licensure it has become a rare cause of such infection

Question 17

outline the timing and route of administration of the DPT-HepB-HiB vaccine

Answer 17

Vaccine is inactivated (injected).
 The preferred site for infants and young children is intramuscular in the vastus lateralis muscle in the anterolateral thigh. The preferred injection site in older children and adults is the deltoid muscle.
 Timing of vaccination (in Zambia):
 At 6 weeks: DPT-HepB-HiB 1
 After 4 weeks of DPT-HepB-HiB 1: DPT-HepB-HiB 2
 After 4 weeks of DPT-HepB-HiB 2: DPT-HepB-HiB 3

Question 18

what is the rationale for MMR vaccines?

Answer 18

Rational for vaccine: immunizes against 3 viral diseases:
 Measles: a severe illness with complications that include pneumonia associated with significant mortality.
 Mumps: most commonly associate with parotitis but may also cause meningoencephalitis and orchitis
 Rubella: causes a mild viral syndrome in children but may cause severe birth defects in offspring of susceptible women infected during pregnancy

Question 19

outline the timing of the MMR vaccine

Answer 19

 Timing of vaccination (in Zambia):
 At 9 months or soon after unless if symptomatic HIV
 At 18 months or soon after unless if symptomatic HIV

Question 20

what is the rationale of the ROTA vaccine?

Answer 20

 Rationale for vaccine: protection against viral diarrhea causes by Rota virus

Question 21

outline the timing of the rota vaccine

Answer 21

 Timing of vaccination (in Zambia):
 At 6 weeks: ROTA 1
 After 4 weeks of ROTA 1: ROTA 2

Question 22

what are the adverse effects of immunization?

Answer 22

Most vaccine side effects are mild to moderate in severity and occur within the first 24 hours after administration e.g. local inflammation and low grade fever.
 Because MMR and varicella vaccines are live attenuated vaccines fever and rash may occur 1-2 weeks after immunization (i.e. after the incubation period of the virus)
 Serious side effects that may result in permanent disability or be life-threatening are rare (e.g. vaccine related polio after OPV)

Question 23

what are the contraindications of immunization?

Answer 23

ONTRAINDICATIONS
1. Anaphylaxis to a vaccine or its constituents
2. Encephalopathy within 7 days after DTaP vaccine
3. Patients with progressive neurologic disorders including uncontrolled epilepsy should not receive the DTaP vaccine until neurologic status is stabilized.
4. Immunodeficient patients should not receive OPV, MMR and Varicella vaccine.
 Household contacts of immunodeficient patients should not receive OPV as it is shed in stool
5. Pregnant patients should not receive live vaccines.

Question 24

what are the precautions of immunization?

Answer 24

PRECAUTIONS
 For all vaccines, moderate to severe illness (with or without fever) are not contraindication to immunization.
 DTaP vaccine:
 Temperature of 40.5OC within 48hours after prior vaccination
 Collapse or shock-like state within 48hours after prior vaccination
 Seizures within 3 days after prior vaccination
 Persistent, inconsolable crying lasting more than 3 hours occurring within 48 hours after prior vaccination
 MMR and Varicella vaccines
 Immunoglobulin (IVIG) administration within the preceding 3-11 months which might interfere with the patient’s immune response to these vaccines