Immunization and Disease Prevention Flashcards
What does WHO say is the 2 public health interventions that have the greatest impact?
- clean water
- vaccines
Aim for the Malawi Expanded Programme on Immunization (EPI)?
Aims to decrease childhood morbidity and mortality from vaccine preventable diseases
- It is largely based on the WHO-recommended immunization schedule and guidelines
What is an immunization?
It is the process of inducing immunity against a specific disease
What are the types of immunity?
- passive(through administration of antibody)
- active(antigen or toxoid administration)
- Produces a prolonged humoral and/or cellular immune response
- Vaccines can be whole or parts of microorganisms
What are the types of vaccines?
- bacterial vaccines
- viral vaccines
What are bacterial vaccines?
- Whole organism e.g., inactivated oral typhoid vaccine
- Inactivated toxins e.g., diphtheria and tetanus vaccines
- Specific antigens e.g., Haemophilus influenzae b and pneumococcal polysaccharide vaccines
What are viral vaccines?
- Attenuated live viruses e.g. measles, polio and rotavirus vaccines
- Viral components e.g. hepatitis B vaccines
What is Bacillus Calmette-Guerin (BCG)?
- Freeze-dried live attenuated strain of Mycobacterium bovis
- Limited effectiveness in preventing pulmonary tuberculosis (about 50% efficacy)
- More (80%) effective against milliary and meningeal TB
- Contraindicated in symptomatic HIV infection (AIDS) or immunosuppressive conditions
What is the measles vaccine?
- Attenuated virus
- The WHO recommends immunization at nine months
- Earlier immunization (e.g at six months) would have limited immunogenicity
What is pneumococcal conjugate vaccine (PCV)?
- Includes the 13 of the 93 pneumococcal serotypes
- Three doses given at 6, 10 and 14 weeks
- Less efficacious in HIV-infected children (65% vs 83%) in reducing invasive pneumococcal disease
PCV has resulted in?
- Reduction in hospitalization for all cause pneumonia (30—40%)
- Reduction of acute otitis media in middle and high income countries (15-40% )
What is hepatitis B vaccine?
- Recombinant hepatitis B vaccine provided at 6,10,14 weeks
- Infants born to HBsAg+ mothers should receive both 0.5ml HepB immunoglobulin within 12 hours of birth and hepatitis B vaccine
Describe the Hemophilus influenzae type b (Hib) vaccine?
- Is part of a multi-component vaccine (DPT-HepB-Hib)
- Protects against epiglottitis, Hib meningitis, pneumonia, and osteomyelitis
What is the impact of Hib?
- has reduced invasive hib disease ( > 90%)
- Has reduced radiographically proved pneumonia (20-25%)
Describe the pertussis vaccine?
used against whooping cough