19May06KL Vadheim Lecture 41 Hib, Pneumo, Hep A and B MedCh 401 Lecture 4.
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Transcript of 19May06KL Vadheim Lecture 41 Hib, Pneumo, Hep A and B MedCh 401 Lecture 4.
19May06 KL Vadheim Lecture 4 1
Hib, Pneumo, Hep A and B
MedCh 401
Lecture 4
19May06 KL Vadheim Lecture 4 2
Haemophilus influenzae b
• Gram negative coccobacillus
• Respiratory pathogen, primarily of children
• Encapsulated and unencapsulated strains
• Unencapsulated strains from respiratory tracts of adults
19May06 KL Vadheim Lecture 4 3
Hib Transmission• Person-to-person
• Respiratory droplets, contact with respiratory secretions
• Humans are only host
• May be carried in respiratory tract for long periods and transmitted to many people before causing disease
19May06 KL Vadheim Lecture 4 4
H. influenzae capsule
• Composed of polyribosylribitol phosphate (PRP), a repeating polymer of ribosyl and ribitol phosphate
• Polysaccharide
• Six serotypes, a - f
19May06 KL Vadheim Lecture 4 5
Type b capsule
• Antibody to serotype b conferred type-specific protection
• Type b strains account for 95% of all strains causing invasive disease ( bacteremia and meningitis)
19May06 KL Vadheim Lecture 4 6
Hib vaccine efficacy
• Incidence of invasive Hib disease in children <5 years of age has dropped from >20/ 100,000 in 1990 to near zero in 2004
19May06 KL Vadheim Lecture 4 7
Composition of Hib vaccinesVaccine Component,per 0.5 ml dose
HibTITER(HbOC)Lederle/Wyeth
PedvaxHIB(PRP-OMP)Merck
ActHIB(PRP-T)Sanofipasteur
Comvax(PRP-OMPHepB)Merck
Purified H. influenzaeb capsular saccharide
10 g 7.5 g 10 g 7.5 g
Diphtheria CRM197 25 g
N. meningitidis OMP 125 g 125 g
Tetanus toxoid 24 gAluminum adjuvant 225 g 225 g
Sucrose 8.5%
Sodium borohydrate 35 gNaCl 0.9 % 0.9 %
Preservatives None None NoneClear, colorlesssolution
Slightlyopaque whitesuspension
Lyophilized,with salinediluent
Slightlyopaque whitesuspension
19May06 KL Vadheim Lecture 4 8
ActHIB
• Lyphilized vaccine
• Reconstituted with:– Saline– DTP (sanofi Pasteur)– DTaP (Tripedia; sanofi Pasteur)
19May06 KL Vadheim Lecture 4 9
Hib Conjugates
• C. diphtheriae CRM197 - nontoxic variant of diphtheria toxin
• Tetanus toxin - toxoided with formalin
• Outer Membrane Protein Comples from B11 strain of N. meningiditis serogroup B
19May06 KL Vadheim Lecture 4 10
Manufacturing processes• H. influenzae grown in fermenters• PRP purified from cells• Conjugates grown in fermenters, proteins purified,
tetanus toxin toxoided• Conjugation reactions:
– ActHIB PRP covalently bound to tetanus toxoid
– HibTITET PRP coupled to CRM197 by reductive amination
– PedVaxHIB PRP covalently bound to N. meningitidis outer membrane protein complex (OMPC)
19May06 KL Vadheim Lecture 4 11
Pneumococcal Disease• Leading cause of morbidity and mortality
for all ages, worldwide
• U.S. annual incidence: – 15-30 cases/100k– case fatality rate 15-20%
• Major cause of :– invasive infections: bacteremia, meningitis– pneumonia, upper respiratory disease, acute
otitis media, sinusitis
19May06 KL Vadheim Lecture 4 12
Streptococcus pneumoniae
• Gram + coccus
• Increasingly resistant to antimicrobial agents
• Commonly occurs as carrier state
• Both capsulated and non-capsulated
• ~90 serotypes
19May06 KL Vadheim Lecture 4 13
Pneumococcal Vaccines
Component,per 0.5 ml dose
Prevnar (Wyeth) Pneumovax 23 (Merck)
16 g total polysaccharide 575 g total polysaccharideS. pneumoniaecapsularantigens
2 g each:4, 9V, 14, 18C,19F, 23F
4g 6B 25 g each of serotypes: 1, 2, 3, 4, 5, 6B,7F, 8, 9N, 9V, 10A, 11, 12F, 14, 15B, 17F,18C, 19F, 19A, 20, 22F, 23F, 33F
CRM197 20g
Aluminumadjuvant
0.125 mg
Phenol(preservative)
0.25%
19May06 KL Vadheim Lecture 4 14
Comparative efficacy
• Prevnar - 100%
• Pneumovax - ~57%
19May06 KL Vadheim Lecture 4 15
Capsular serotypes
• Differ in prevalence
19May06 KL Vadheim Lecture 4 16
Pneumococcal Vaccines
• Serotypes 4, 6B, 9V, 14, 18C, 19F and 23F (Prevnar) have been responsible for ~80% of invasive pneumococcal disease in children <6
• Pneumovax-23 - additional 16 serotypes gains protection against ~10%
19May06 KL Vadheim Lecture 4 17
Manufacturing Pneumococcal vaccine
• Pneumovax 23 - capsular polysaccharides purified from 23 types of S. pneumoniae
• Prevnar - capsular polysaccharides from 6 S. pneumoniae serotypes are purified, then conjugated to diphtheria CRM197 protein
19May06 KL Vadheim Lecture 4 18
Hepatitis A
• Systemic viral infection with liver pathology
• Symptoms indistinguishable from most other viral hepatitis infections
• Incubation period is ~15 - 50 days
• Disease may range from asymptomatic, to hepatitis, to fatal infection
19May06 KL Vadheim Lecture 4 19
HepA Transmission• Fecal-oral transmission
– Person-to-person– Infected food or water
• Replicates in the liver
• Humans are the only natural host
• No chronic infection or carrier state
• Virus shed in feces ~3 weeks, starting 1-2 weeks before symptoms
19May06 KL Vadheim Lecture 4 20
HepA vaccine efficacy
• >95% seropositive after one dose
• 100% seropositive after two doses
19May06 KL Vadheim Lecture 4 21
Hepatitis A Manufacturing
• Attentuated virus is propagated in MRC-5 cells
• Cells are harvested by centrifugation
• Cells are lysed to form a viral suspension
• Virus is inactivated with formalin
• Adsorbed onto aluminum adjuvant
19May06 KL Vadheim Lecture 4 22
Hepatitis A Vaccines
Component, per dose Havrix (GSK) Vaqta Merck)
Adult (1ml)
Pediatric(0.5 ml)
Adult(1 ml)
Pediatric(0.5 ml)
Viral antigen 1440 EL.U. 720 EL.U. 50 U 25 U
Aluminum adjuvant 0.5 mg 0.25 mg 0.45 mg 0.225 mg
Sodium Borate 70g 35 g
NaCl 0.9% 0.9%
2-Phenoxyethanol 0.5% 0.5%
Amino acid supplementin PBS
0.3% 0.3%
Polysorbate 20 0.05 mg/ml 0.05 mg/ml
Residual MRC-5 cellproteins
<5g/ml <5g/ml
19May06 KL Vadheim Lecture 4 23
Hepatitis B• Systemic infection with liver pathology
• Symptoms indistinguishable from Hepatitis A or other viral hepatitis infections
• Can cause primary hepatocellular carcinoma
• Lifetime risk of infection:– 100% for high-risk groups (e.g., IV drug users)– <20% for general U.S. population
19May06 KL Vadheim Lecture 4 24
Hepatitis B Carriers
• 200-300 million worldwide
• 1-1.25 million in U.S.
• 90% of neonates and 6-10% of infected adults will become carriers
• Carriers can infect others
19May06 KL Vadheim Lecture 4 25
Hepatitis B Transmission• No host outside humans (no other reservoir
of infection)
• Bloodborne transmission – parenteral– mucosal – perinatal
• Communicable 1-2 months before and after onset of symptoms
19May06 KL Vadheim Lecture 4 26
Hepatitis B Vaccine
• Recombinant
• Old vaccine was pooled human plasma
19May06 KL Vadheim Lecture 4 27
Hep B Vaccine Manufacturing• Cloned, purified Hepatitis B Surface Antigen
(HBsAg) • Genetically engineered into Saccharomyces
cerevisiae (yeast) cells• Yeast grown in fermenters• HBsAg release by yeast cell disruption• Purified • Formalin-treated (Recombivax only)• Adsorbed to aluminum adjuvants
19May06 KL Vadheim Lecture 4 28
Hepatitis B VaccinesComponent,
per doseRecombivax HB
MerckEngerix-B
GSK
Pediatric0.5 mldose
Adult1 ml dose
Dialysis1 ml dose
Pediatric0.5 ml
Adult1 ml
Hepatitis B surfaceantigen (HbsAg)
5 g 10 g 40 g 10g 20g
Aluminum adjuvant 0.5 mg 0.5 mg 0.5 mg 0.25 mg 0.5 mg
Thimerosal None None None Trace Trace
NaCl 9 mg/ml 9 mg/ml