• Product Name: Haemophilus b Conjugate Vaccine (Tetanus Toxoid Conjugate)
• Tradename: ActHIB
• Manufacturer: Sanofi Pasteur, SA
• Vaccine Ontology ID: VO_0000004
• CDC CVX code: 48
• Type: Conjugate vaccine
• Status: Licensed
• Location Licensed: USA (License #1724)
• Host Species for Licensed Use: Human
• Antigen: Haemophilus b capsular polyribosyl-ribitol-phosphate(PRP)- tetanus toxoid
• Preparation: The vaccine consists of the Haemophilus b capsular polysaccharide (polyribosyl-ribitol-phosphate, PRP), a high molecular weight polymer prepared from the Haemophilus influenzae type b (HiB) strain 1482 grown in a semi-synthetic medium, covalently bound to tetanus toxoid. The tetanus toxoid is prepared by extraction, ammonium sulfate purification, and formalin inactivation of the toxin from cultures of Clostridium tetani (Harvard strain) grown in a modified Mueller and Miller medium. The toxoid is filter sterilized prior to the conjugation process. When ActHIB vaccine is reconstituted with saline diluent, each single dose of 0.5 mL is formulated to contain 10 μg of purified capsular polysaccharide conjugated to 24 μg of inactivated tetanus toxoid, and 8.5% of sucrose (ActHIB 2005).
• Immunization Route: Intramuscular injection (i.m.)
• Virulence: Not virulent
• Storage: 2° to 8°C (35° to 46°F). DO NOT FREEZE.
• Approved Age for Licensed Use: Infants and children ages 18 months to 2 years old (ActHIB 2005).
• Contraindication: The vaccine should not be administered to anyone with a known hypersensitivity to any component of the vaccine (FDA: ACTHIB).
• Description: ActHIB vaccine was among the first conjugated Hib vaccines developed at the National Institutes of Health (NIH). It is now manufactured by Sanofi Pasteur SA in Lyon, France. The conjugation process changes the polysaccharide from a “T-cell–independent antigen” to a “T-cell–dependent antigen”, which greatly improves immunogenicity, particularly in young children. In addition, repeated doses elicit a substantial booster response in children who have been previously vaccinated (ActHIB 2005).

• Product Name: Haemophilus b Conjugate
• Tradename: COMVAX
• Manufacturer: Merck & Co., Inc
• Vaccine Ontology ID: VO_0000028
• CDC CVX code: 51
• Type: Conjugate vaccine
• Status: Licensed
• Location Licensed: USA (License #0002)
• Host Species for Licensed Use: Human
• Adjuvant:
  • VO ID: VO_0000127
  • Description: Description: It is a vaccination against invasive disease caused by Haemophilus influenzae type b and against infection caused by all known subtypes of hepatitis B virus in infants 6 weeks to 15 months of age born of HBsAg negative mothers.
• Preparation: It is grown in complex fermentation media. It is then purified from the culture broth by purification procedures which include ethanol fractionation, enzyme digestion, phenol extraction and diafiltration (FDA: COMVAX).
• Immunization Route: Intramuscular injection (i.m.)
• Storage: Store vaccine at 2-8°C (36-46*F). Storage above or belew the recommended temperature may reduce potency. DO NOT FREEZE since freezing destroys potency.(Comvax)
• Approved Age for Licensed Use: 2-15 months of age.
• Contraindication: Hypersensitivity to any component of the vaccine.
• Description: Immunization of persons 6 weeks to 15 months of age born to hepatitis B surface antigen (HBsAg) negative mothers.

• Vaccine Ontology ID: VO_0000627
• Type: Subunit vaccine
• Antigen: Haemophilus b capsular polysaccharide (polyribosyl-ribitol-phosphate, PRP)
• Preparation: H. influenzae type b vaccine, coded as M1 and M2, respectively, was prepared for this trial in Boston and bottled in ten-dose vials (BenVenue Laboratories, Inc., Ohio). The lyophilized vaccine was kept at -20 C; after reconstitution with sterile, pyrogen-free water is was kept at + 4 C and used within eight hours (Peltola et al., 1977).

• Product Name: H. influenzae type b conjugate vaccine (Hb-OC)
• Tradename: HIBTITER
• Vaccine Ontology ID: VO_0000659
• Type: conjugate vaccines
• Antigen: Haemophilus influenzae type b capsular polyribosyl-ribitol-phosphate(PRP)-Diphtheria CRM197 Protein (HibTITER 2007).
• Preparation: The oligosaccharides are derived from highly purified capsular polysaccharide, polyribosylribitol phosphate, isolated from Haemophilus b strain Eagan grown in a chemically defined medium (a mixture of mineral salts, amino acids, and cofactors). The oligosaccharides are purified and sized by diafiltrations through a series of ultrafiltration membranes, and coupled by reductive amination directly to highly purified CRM197. CRM197 is a nontoxic variant of diphtheria toxin isolated from cultures of Corynebacterium diphtheriae C7 (β197) grown in a casamino acids and yeast extract-based medium that is ultrafiltered before use. CRM197 is purified through ultrafiltration, ammonium sulfate precipitation, and ion-exchange chromatography to high purity. The conjugate is purified to remove unreacted protein, oligosaccharides, and reagents; sterilized by filtration; and filled into vials (HibTITER 2007). The vaccine is a clear, colorless solution. Each single dose of 0.5 mL is formulated to contain 10 μg of purified Haemophilus b saccharide and approximately 25 μg of CRM197 protein (HibTITER 2007).
• Description: Linkage of Haemophilus b saccharides to a protein such as CRM197 converts the saccharide (HbO) to a T-dependent (HbOC) antigen, and results in an enhanced antibody response to the saccharide in young infants that primes for an anamnestic response and is predominantly of the IgG class.12 Laboratory evidence indicates that the native state of the CRM197 protein and the use of oligosaccharides in the formulation of HibTITER enhances its immunogenicity (Weinberg et al., 1988).
  In most cases HibTITER was administered concomitantly with other vaccines including DTP, DTaP, hepatitis B vaccine, IPV, OPV, pneumococcal 7-valent conjugate vaccine, MMR, and/or meningococcal group C conjugate vaccine (not licensed in the US).

• Vaccine Ontology ID: VO_0000474
• Type: Inactivated or "killed" vaccine
• Antigen: whole cell
• Preparation: The vaccine was enteric-coated tabletcontaining 10th power numbers of killed H influenzae with sodium tauroglycocholate. The organism was a non-serotypable biotype 2 H influertzae, and was formalin killed. The tablets were quality controlled for acid resistance, release in alkali, and sterility of content (Clancy et al., 1985).
• Immunization Route: Oral immunization
• Virulence: no virulence
• Description: Acute exacerbations of bronchitis and chronic obstructive pulmonary disease often occur in people with compromised respiratory function.The bacterial agents responsible for the acute exacerbations are commonly an expansion of the patient's own respiratory tract microbiota often following the arrival of a new strain of normal commensal. Nontypeable Haemophilus influenzae is of particular importance because it is the most commonly isolated bacterium at times of exacerbation (Foxwell et al., 2006). Successful vaccines for infections caused by H. influenzae serotype B (Hib) depend on immunity stimulated against the type-specific polysaccharide capsule of Hib. But this is not effective against infections caused by organisms lacking the polysaccharide, such as nontypeable H. influenzae. The oral whole-cell nontypeable. H. influenzae vaccine is developed to prevent nontypeable H. influenzae infections (Foxwell et al., 2006).

• Vaccine Ontology ID: VO_0000473
• Type: Subunit vaccine
• Antigen: NTHi rLP4/rLP6 and M. catarrhalis UspA2 proteins(Mason et al., 2004)
• Pal gene engineering:
  • Type: recombinant
  • Description: The P6 protein is an integral outer membrane protein and, as a peptidoglycan-associated lipoprotein , is thought to be necessary for the integrity of the bacterium’s outer membrane.(Mason et al., 2004)
  • Detailed Gene Information: Click Here.
• yscF gene engineering:
  • Type: recombinant
  • Description: The P4 protein is an integral outer membrane protein that has a role in acquiring hemin and nucleosides.(Green et al., 1991)
  • Detailed Gene Information: Click Here.
• Adjuvant:
  • VO ID: VO_0001239
• Preparation: Recombinant nontypeable H. influenzae LP4 (rLP4) and LP6 (rLP6) were expressed in E. coli strain BLR and purified (Mason et al., 2004). M. catarrhalis UspA was purified from outer membrane vesicles prepared from isolate O35E (Mason et al., 2004).
• Description: Nontypeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis are two of the leading causes of bacterial otitis media. The immunodominant exposed surface molecules of NTHi, including lipooligosaccharide (LOS) and outer membrane proteins, are extremely variable antigenically and infection with one strain provides immunity only to that strain. Thus, NTHi vaccine efforts have focused on antigenically conserved outer membrane protein such as the P4 and P6 proteins and LOS-conjugates. While the surface of M. catarrhalis appears to be much less antigenically variable, vaccine efforts have also focused on conserved outer membrane proteins and LOS. The ubiquitous cell surface protein A (UspA) of M. catarrhalis is a particularly interesting vaccine candidate (Mason et al., 2004).

• Vaccine Ontology ID: VO_0000480
• Type: Conjugate vaccine
• Antigen: lipooligosaccharide (LOS)
• Preparation: Tetanus toxoid (TT) was obtained from Pasteur-Merieux Connaught and purified through an S-300 Sephacryl column. LOS was prepared from NTHi strain 9274. It was used for preparation of dLOS and its derivative with adipic acid dehydrazide (AH–dLOS). The fusion dLOS–TT was further synthesized (Gu et al., 2003).
• Description: Nontypeable Haemophilus influenzae (NTHi) accounts for about one-third of purulent otitis media (OM) in children and is a common cause of pulmonary infection in adults with decreased resistance. Lipooligosaccharide(LOS) is both a virulence factor and a potential protective surface antigen. Human antibodies and mouse monoclonal antibodies against LOS are produced and can be bactericidal for NTHi (Gu et al., 2003).

• Product Name: Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate)
• Tradename: PedvaxHIB
• Manufacturer: Merck & Co, Inc.
• Vaccine Ontology ID: VO_0000083
• CDC CVX code: 49
• Type: Conjugate vaccine
• Status: Licensed
• Location Licensed: USA
• Host Species for Licensed Use: Human
• Antigen: Haemophilus b capsular polyribosyl-ribitol-phosphate( PRP)-Neisseria meningitidis outer membrane protein complex (OMPC)
• Adjuvant:
  • VO ID: VO_0000127
  • Description: PedvaxHIB is a highly purified capsular polysaccharide (polyribosylribitol phosphate or PRP) of Haemophilus influenzae type b (Haemophilus b, Ross strain) that is covalently bound to an outer membrane protein complex (OMPC) of the B11 strain of Neisseria meningitidis serogroup B. The covalent bonding of the PRP to the OMPC which is necessary for enhanced immunogenicity of the PRP is confirmed by quantitative analysis of the conjugate’s components following chemical treatment which yields a unique amino acid
• Preparation: Haemophilus influenzae type b and Neisseria meningitidis serogroup B are grown in complex fermentation media. The PRP is purified from the culture broth by purification procedures which include ethanol ractionation, enzyme digestion, phenol extraction and diafiltration. The OMPC from Neisseria meningitidis is purified by detergent extraction, ultracentrifugation, diafiltration and sterile filtration (PedvasHIB).
• Immunization Route: Intramuscular injection (i.m.)
• Virulence: No virulence
• Storage: Store vaccine at 2-8°C (36-46°F).
• Approved Age for Licensed Use: Infants and children 2 to 71 months of age (PedvasHIB).
• Contraindication: Hypersensitivity to any component of the vaccine or the diluent or persons who develop symptoms suggestive of hypersensitivity after an injection should not receive further injections of the vaccine.
• Description: PedvaxHIB is a highly purified capsular polysaccharide (polyribosylribitol phosphate or PRP) of Haemophilus influenzae type b (Haemophilus b, Ross strain) that is covalently bound to an outer membrane protein complex (OMPC) of the B11 strain of Neisseria meningitidis serogroup B. The covalent bonding of the PRP to the OMPC which is necessary for enhanced immunogenicity of the PRP is confirmed by quantitative analysis of the conjugate’s components following chemical treatment which yields a unique amino acid (PedvasHIB).
  
  Nonconjugated PRP vaccines are capable of stimulating B-lymphocytes to produce antibody without the help of T-lymphocytes (T-independent). The responses to many other antigens are augmented by helper T-lymphocytes (T-dependent). PedvaxHIB is a PRP-conjugate vaccine in which the PRP is covalently bound to the OMPC carrier29 producing an antigen which is postulated to convert the T-independent antigen (PRP alone) into a T-dependent antigen resulting in both an enhanced antibody response and immunologic memory (Marburg 1986).

• Product Name: H. influenzae type b conjugate vaccine (PRP-D)
• Tradename: ProHIBiT
• Vaccine Ontology ID: VO_0000660
• Type: conjugate vaccines
• Antigen: Haemophilus b capsular polyribosyl-ribitol-phosphate(PRP)-diphtheria toxoid (D)
• Preparation: ProHIBiT was prepared from the purified capsular polysaccharide, a polymer of ribose, ribitol and phosphate (PRP) of the Eagen Haemophilus influenzaetype b strain covalently bound to diphtheria toxoid (D) and dissolved in sodium phosphate buffered isotonic sodium chloride solution. The polysaccharide- protein conjugate molecule is referred to as PRP- D. Thimerosal (mercury derivative) 1:10,000 is added as a preservative. The vaccine is a clear, colorless solution. Each single dose of 0.5 mL is formulated to contain 25 µg of purified capsular polysaccharide and 18 µg of diphtheria toxoid protein (ProHIBiT 2007).
• Description: The manufacturing process utilizes a technology of covalent bonding the capsular polysaccharide of Haemophilus influenzae type b to diphtheria toxoid, to produce an antigen which is postulated to convert a T- independent antigen into a T- dependent antigen. The protein carries both its own antigenic determinants and those of the covalently bound polysaccharide. As a result of the conjugation to protein, the polysaccharide is presented as a T- dependent antigen resulting in both an enhanced antibody response and an immunologic memory (Lepow et al., 1987).

Human Response

• Vaccination Protocol: ActHIB vaccine is indicated for active immunization of infants and children 2 through 18 months of age for the prevention of invasive disease caused by H influenzae type b.
  
  The number of doses of ActHIB vaccine indicated depends on the age at which immunization is begun. For previously unvaccinated children, the first, second, third and fourth dose were given at 2, 4, 6, and 12 to 18 months. A child 7 to 11 months of age should receive 2 doses at 8-week intervals and a booster dose at 15 to 18 months. A child 12 to 24 months of age should receive 1 dose and a booster dose 2 months later. Preterm infants should be vaccinated according to their chronological age from birth (ActHIB 2005).
  
  ActHIB vaccine reconstituted with the saline diluent (0.5 mL per dose) should be administered intramuscularly in the outer aspect of the midthigh or deltoid. Do not inject intravenously. It should not be injected into the gluteal area or areas where there may be a nerve trunk. When administering multiple vaccines during a single visit, separate injection sites and syringes should be used. Administer ActHIB vaccine within 24 hours after reconstitution (ActHIB 2005).
• Side Effects: The most common side effects with ActHIB vaccine may include redness, swelling, and tenderness where the injection was given; fever, fussiness, and drowsiness. Other side effects may occur. ActHIB vaccine should not be given to children who have had a serious allergic reaction (anaphylactic reaction) after a previous dose of the vaccine. When administering an intramuscular injection, like ActHIB vaccine, to people with bleeding disorders, caution should be exercised because they may develop a serious bruise or collection of blood at the injection site (ActHIB 2005).
• Efficacy: Two clinical trials supported by the National Institutes of Health (NIH) compared the anti-PRP (polyribosyl-ribitol-phosphate) antibody responses to three Hib conjugate vaccines in racially mixed populations of children. In these trials, ActHIB vaccine consistently produced high rates of seroconversion (83% to 97%) to antibody levels that correlate with long-term protection (>1.0 µg/mL) following the 3-dose primary series (Decker et al., 1992). Consistently high rates of seroconversion (83% to 99%) with an ActHIB vaccine 3-dose primary series were also obtained in 11 non-comparative clinical trials (N=1225) (Fritzell et al., 1992). Additionally, three NIH trials demonstrated that ActHIB vaccine produced consistently high geometric mean anti-PRP antibody titers (Decker et al., 1992).

Human Response

• Vaccination Protocol: COMVAX SHOULD NOT BE USED IN INFANTS YOUNGER THAN 6 WEEKS OF AGE.(Comvax)
• Immune Response: No impairment of immune response to individually tested vaccine antigens
• Side Effects: Injection site reactions as well as systemic complaints occur.
• Efficacy: A protective efficacy of 93% was achieved with an anti-PRP level of >l.O mcg/mL in 60% of vaccines and a GMT of 1.43 mcg/mL one to three months after the second dose.(Comvax)
• Description: It is a vaccination against invasive disease caused by Haemophilus influenzae type b and against infection caused by all known subtypes of hepatitis B virus in infants 6 weeks to 15 months of age born of HBsAg negative mothers.

Human Response

• Vaccination Protocol: A total of 98,272 Finnish children, or 75.5% of the 130,178 children between the ages of 3 months to 5 years in the area, were vaccinated in three provinces in Finland. The campaign took place within two weeks in November 1974. A booster dose was given three months later to those who had been 3 to 17 months old at the time of the primary vaccination. The participation in the booster vaccination was 73.3%. Every other child (total, 49,295) received the group A meningococcal vaccine, every other (total, 48,977) the H. influenzae type b vaccine, coded as M1 and M2, respectively: All age groups and both sexes were equally represented. The dose of H. influenzae type b was 12.7 ug of polysaccharide in a volume of 0.5 ml except for the smallest infants (ages 3 to 5 months) who received only half of this dose. The subcutaneous injection was given by needle and syringe, usually into the upper part of the right arm. Children with an acute febrile disease, extensive eczema, or symptomatic asthma were not vaccinated (Peltola et al., 1977).
• Persistence: The serum antibodies induced by the vaccination proved short-lived (less than 6 months) in the infants younger than 18 months. Elevated serum antibody levels were detectable for 1and half year but less than 3 and half years in the children who were vaccinated when 18 to 35 months old. In the children who were 3 to 5 years old when vaccinated, the elevated anti-H influenzae type b capsular polysaccharide levels persisted for at least 3 and half years (Kayhty et al., 1984).
• Immune Response: The serum antibody response to the H. influenzae type b polysaccharide, measured by radioimmunoassay, was poor in children below 18 months of age and good in those above it. No effect of the vaccine could be seen on the nasopharyngeal carriage of H. influenzae type b, which was approximately 6% in this age group (Peltola et al., 1977).
• Side Effects: Adverse effects of the vaccine were mild
• Efficacy: The protection as well as senim antibody response was strongly age-dependent. Among children who had received the H. influenwe type b vaccine when 18 months of age or older, there were no cases of bacteremic disease caused by H. influenzae type b in the first year after vaccination. At the same time 1 1 such cases were seen in the control group of the same age, a highly significant difference. In the second year after vaccination two cases occurred in the H. influenzoe type b-vaccinated group, five in the meningocoecal-group A vaccinated group. No protection Was seen among children who had been younger than 18 months when vaccinatedı even if they received a booster dose of the vaccine.

Human Response

• Vaccination Protocol: Haemophilus b Conjugate Vaccine (Diphtheria CRM197 Protein Conjugate) HibTITER is indicated for the immunization of children 2 months to 71 months of age against invasive diseases caused by H. influenzae type b. HibTITER is for intramuscular use only.
  
  For infants 2 to 6 months of age, the immunizing dose is three separate injections of 0.5 mL given at approximately 2-month intervals. Previously unvaccinated infants 12 from 7 through 11 months of age should receive two separate injections approximately 2 months apart. Children from 12 through 14 months of age who have not been vaccinated previously receive one injection. All vaccinated children receive a single booster dose at 15 months of age or older, but not less than 2 months after the previous dose. Previously unvaccinated children 15 to 71 months of age receive a single injection of HibTITER. Preterm infants should be vaccinated with HibTITER according to their chronological age, from birth (AAPC 1991).
  
  Data support that HibTITER may be interchanged with other Haemophilus influenzae type b conjugate vaccines for the primary immunization series and booster dose.
  Each dose of 0.5 mL is formulated to contain 10 μg of purified Haemophilus b saccharide and approximately 25 μg of CRM197 protein.
• Persistence: Long-term persistence of the antibody response was observed. More than 80% of 235 infants who received three doses of vaccine had an anti-HbPs antibody level ≥ 1 μg/mL at 2 years of age (Reinholdt et al., 1997).
• Side Effects: Side effects associated with a single vaccination of HibTITER include fever, local reactions, rash, diarrhea , vomiting , prolonged crying.
• Efficacy: The immunogenicity of HibTITER was evaluated in US infants and children.Infants 1 to 6 months of age at first immunization received three doses at approximately 2-month intervals. Children 7 to 11 and 12 to 14 months of age received 2 doses at the same interval.Children 15 to 23 months of age received a single dose. HibTITER was highly immunogenic in all age groups studied, with 97% to 100% of 1,232 infants attaining titers of ≥ 1 μg/mL and 92% to 100% for bactericidal activity (HibTITER 2007).
  
  Postlicensure surveillance of immunogenicity was conducted during the distribution of the first 30 million doses of HibTITER and during the time period over which Haemophilus b disease in children has been decreasing significantly in areas of extensive vaccine usage.After three doses, titers ranged from 2.37 to 8.45 μg/mL with 67% to 94% attaining ≥ 1 μg/mL (HibTITER 2007).
  
  A comparative clinical trial was performed in Finland where approximately 53,000 infants received HibTITER at 4 and 6 months of age and a booster dose at 14 months in a trial conducted from January 1988 through December 1990. Only two children developed Haemophilus b disease after receiving the two-dose primary immunization schedule. One child became ill at 15 months of age and the other at 18 months of age; neither child received the scheduled booster at 14 months of age. No vaccine failure has been reported in children who received the two-dose primary series and the booster dose at 14 months of age. Based on more than 32,000 person-years of follow-up time, the estimate of efficacy is about 95% when compared to historical control groups followed between 1985 and 1988.20 Historical controls were used since all infants received one of two Haemophilus b conjugate vaccines during the period of the trial (HibTITER 2007).

Human Response

• Vaccination Protocol: A prospective, double-blind, placebo-controlled trial was performed during the Australian winter of 1983. 50 patients with established COLD were recruited from the chest clinic of the Royal Newcastle Hospital and randomly allocated to three groups. No patient was taking corticosteroids or mmunosuppressive agents, but many took bronchodilator drugs and antibiotics. Three groups were tested: one took enteric-coated glucose tablets; the second took enteric-coated tablets containing 25 mg sodium tauroglycocholate; while the third took enteric-coated tablets each containing 10th power of killed H influenzae with sodium tauroglycocholate. Three courses of tablets were given at 0, 28, and 56 days. Each course consisted of two tablets taken before breakfast each day for 3 consecutive days. Each patient was assessed at 0, 28, 56 and 84 days (Clancy et al., 1985).
• Persistence: Over a similar 3-month period through the subsequent winter (1984), during which no tablets were given, 11 of 22 patients available from the combined placebo groups had one or more acute episodes of bronchitis, while 4 of 14 available from the group who had previously taken the H influenzae tablets, had acute episodes. This trend towards continued protection was not significant (Clancy et al., 1985).
• Efficacy: The vaccine provided a more than 9007o protection rate against clinical episodes of acute bronchitis, with no noticeable effect on the incidence of upper respiratory tract infection. No significant difference in the incidence of acute upper respiratory tract infection was detected between the three groups. There was significant reduction in both the number of subjects with episode(s) of acute bronchitis (p<0 . 005), and the absolute number of episodes of acute bronchitis (p<0 . 002), in the group taking tablets containing H influenzae. If results were analysed according to the relative incidence of infection, there was a tenfold reduction in incidence in those taking the active tablet (p<0 . 001) (Clancy et al., 1985). No significant difference in antibody level to HI/H2 antigen existed between the three groups at zero time or at any point in the trial.

Human Response

• Vaccination Protocol: Randomised, double-blind, placebo-controlled study of six months duration including winter. 40 patients with chronic bronchitis, 3 withdrawals, 2 from placebo and 1 from active treatment group. 20 given a placebo, 20 vaccinated. Mean age 46.3, sex ratio (m/f) 8/12 for the placebo group and 47.4, sex ratio 11/9 for the vaccine group. Vaccine consisting of 10 to the 11th formalin killed nontypeable Haemophilus infuenzae in 3 courses of enteric coated tablets given at days 0, 28 and 56. Each course consisted of two tablets given over three consecutive days before breakfast. Placebos were enteric coated glucose tablets (Clancy et al., 1990).
• Efficacy: The vaccine resulted in a marked reduction in the total number of episodes of acute bronchitis and acute wheezy bronchitis concomitant with a reduction in antibiotic use. They also warned that the small group number and a possible favouring of the vaccine group might have occurred. They also demonstrated a prevention of increase of H. inuenzae colonization in the vaccinated group (Clancy et al., 1990).

Human Response

• Vaccination Protocol: Randomised, double-blind, prospective placebo-controlled study of 12 months duration starting in October. 62 patients with chronic bronchitis or more than 2 episodes of acute bronchitis in 2 years. 32 given a placebo,30 vaccinated. Mean age 53.7, sex ratio (m/f) 15/17 for the placebo group and 52.6, sex ratio 15/17 for the vaccine group: Drop-outs were 11 from vaccine group and 4 from placebo group. Vaccine consisting of 10 to the 11th formalin killed nontypeable Haemophilus influenzae in 3 courses of enteric coated tablets given at days 0, 28 and 56. Each course consisted of two tablets given over three consecutive days before breakfast. Placebos were enteric coated glucose tablets (Lehmann et al., 1991).
• Efficacy: the vaccine group had significantly lower acute bronchitic episodes post vaccination than the control group in individuals who had less severe but not severe disease. The carriage rate of H. influenzae also declined in the vaccinated group (Lehmann et al., 1991).

Human Response

• Vaccination Protocol: Randomised, double-blind, placebo-controlled study of 12 months duration starting in March. 77 patients with chronic bronchitis. 10 were withdrawn (7 in placebo group and 3 in vaccine group). 3 from the vaccine group died. 33 given a placebo, 31 vaccinated. Mean age 71.1, sex ratio (m/f) 30/3 for the placebo group and 73.1, sex ratio 22/9 for the vaccine group. Vaccine consisting of 10 to the 11th formalin killed nontypeable Haemophilus influenzae in 3 courses of enteric coated tablets given at days 0, 28 and 56. Each course consisted of two tablets given over three consecutive days before breakfast. Placebos were enteric coated glucose tablets (Tandon et al., 1991).
• Efficacy: A reduction in acute bronchitic episodes in patients who received the vaccine was observed. They also needed to prescribe fewer antibiotics despite the number of individual's requiring antibiotics being similar. A reduction in H. influenzae colonization also occurred in vaccinated individuals (Tandon et al., 1991).

Human Response

• Vaccination Protocol: At weeks of 0, 1, 3 and 5, groups of 10, 6 to 8-week-old, female BALB/c mice were immunized intranasally with 30 μg purified rLP4/rLP6/UspA2 (10 μg each protein) mixed with or without 10 μg RC529-AF in 15 μl of volume. Control mice received Delbecco's phosphate buffered saline (D-PBS) alone or D-PBS with 10 μg RC529-AF, again in 15 μl volumes. The vaccine was delivered by pipette in a volume of 7.5 μl per nostril. The pipette was positioned so that the tip touched the opening of the nostril and liquid was drawn into the nasopharynx during breathing. Immediately following immunization, mice were placed in a supine position for 3~5 min (Mason et al., 2004).
• Immune Response: These proteins combined with RC529-AF administered intranasally to mice elicited (1) significantly increased rLP4/rLP6/UspA2 protein-specific circulating IgG and IgA antibody responses; (2) local rLP4/rLP6/UspA2-specific IgA responses in the respiratory tract. The serum IgG subclass distribution was predominantly IgG2a, representing a Th1 response.
• Challenge Protocol: Two weeks after the final immunization, animals were challenged intranasally with approximately 1 million colony forming units (CFU) of NTHi strain SR7332.P1. Mice were anesthetized, and 5 μl of bacteria were administered into each nostril. Twenty minutes after the challenge, an aliquot of the bacterial suspension was diluted in D-PBS and plated onto brain-heart infusion XV (BHI-XV) agar to determine the actual inoculum. Three days after challenge, nasal turbinates were harvested, weighed, homogenized, serially diluted and plated on BHI-XV plates containing 100 μg/ml streptomycin. Following incubation of plates overnight, colonies were counted, and CFU per gram of nasal tissue were determined (Mason et al., 2004).
• Efficacy: These proteins combined with RC529-AF administered intranasally to mice elicited more than a two log reduction of nasal colonization of NTHi strain SR7332 from the nasal tissues of mice. The antiserum also exhibited bactericidal activities to several strains of M. catarrhalis.

Human Response

• Vaccination Protocol: This is a Phase I clinical trial for this vaccine. Forty healthy adult volunteers of either sex, between 18 and 35 years of age, were recruited and informed consent was obtained. All 40 volunteers received an injection in the deltoid muscle with 0.5 mlof the investigational vaccine (25ug saccharide), and 28 of them also received a second injection in 3–4 months after the first injection. Their injection sites and body temperatures along with other reactions were monitored by a medically credentialled provider or nurse before and 1, 6, 24, and 48 h after each injection. Local and systemic reactions were monitored and sera, taken before and 2, 6, 14, 16, and 38 weeks after injection, were assayed for IgG, IgA, and IgM antibodies to the LOS by ELISA and for bactericidal activity (Gu et al., 2003).
• Immune Response: All volunteers had pre-existing IgG anti-LOS. The geometric mean (GM) level rose from 14 to 40 at 2 weeks, remained at 35 at 6 weeks (40 or 35 versus 14,P <0.01) and dropped to 27 at 14 weeks after the first injection. There was also a rise 2 weeks after the second injection (27 versus 37,P <0.05 ). A total of 52.5% of subjects showed serum-conversion (greater than four-fold increase) after one and two injections. At 38 weeks, the GM IgG anti-LOS was still higher than before initial injection (20 versus 14,P < 0.05). A similar pattern of reactivity was observed for IgA and IgM anti-LOS (Gu et al., 2003).
• Side Effects: Analysis of the frequency and degree of local signs and symptoms at the injection area showed that all reactions were mild or moderate. There were four subjects complained of mild to moderate pain, one subject showed mild to moderate erythema (1–2 cm), two showed mild to moderate induration (1–2 cm). For systemic reactions, two subjects showed temperatures of 37.6 and 37.7 ◦C after the first injection and one subject reached 37.7 ◦C after the second injection. None reported abdominal discomfort or skin rashes. All other complaints were judged to be mild or moderate and medication was rarely required for the symptoms. There was no significant difference in systemic symptoms between two injections except for the incidence of myalgia (P = 0.039) (Gu et al., 2003).

Human Response

• Vaccination Protocol: Liquid PedvaxHIB is indicated for routine vaccination against invasive disease caused by Haemophilus influenzae type b in infants and children 2 to 71 months of age. Liquid PedvaxHIB is ready to use and does not require a diluent. Each 0.5 mL dose of Liquid PedvaxHIB is a sterile product formulated to contain: 7.5 mcg of Haemophilus b PRP, 125 mcg of Neisseria meningitidis OMPC and 225 mcg of aluminum as amorphous aluminum hydroxyphosphate sulfate (previously referred to as aluminum hydroxide), in 0.9% sodium chloride, but does not contain lactose or thimerosal.
  
  Infants 2 to 14 months of age should receive a 0.5 mL dose of vaccine ideally beginning at 2 months of age followed by a 0.5 mL dose 2 months later (or as soon as possible thereafter). When the primary two-dose regimen is completed before 12 months of age, a booster dose is required . Infants born prematurely, regardless of birth weight, should be vaccinated at the same chronological age and according to the same schedule and precautions as full-term infants and children.
  
  Children 15 months of age and older previously unvaccinated against Hib disease should receive a single 0.5 mL dose of vaccine.
  
  In infants completing the primary two-dose regimen before 12 months of age, a booster dose (0.5 mL) should be administered at 12 to 15 months of age, but not earlier than 2 months after the second dose (PedvasHIB).
• Persistence: A booster dose of PedvaxHIB is required in infants who complete the primary two-dose regimen before 12 months of age. This booster dose will help maintain antibody levels during the first two years of life when children are at highest risk for invasive Hib disease.
• Side Effects: The most frequently reported (>1%) adverse reactions, in decreasing order of frequency, were irritability, sleepiness, injection site pain/soreness, injection site erythema (≤2.5 cm diameter), injection site swelling/induration, unusual high-pitched crying, prolonged crying (>4 hr), diarrhea, vomiting, crying, pain, otitis media, rash, and upper respiratory infection (PedvasHIB).
  
  The use of Haemophilus b Polysaccharide Vaccines and another Haemophilus b Conjugate Vaccine has been associated with the following additional adverse effects: early onset Hib disease and Guillain-Barré syndrome (Meekison et al., 1989).
• Efficacy: PedvaxHIB was initially evaluated in 3,486 Native American (Navajo) infants, who completed the primary two-dose regimen in a randomized, double-blind, placebo-controlled study (The Protective Efficacy Study). Each infant in this study received two doses of either placebo or lyophilized PedvaxHIB with the first dose administered at a mean of 8 weeks of age and the second administered approximately two months later. Following the primary two-dose regimen, the protective efficacy of lyophilized PedvaxHIB was calculated to be 93% with a 95% confidence interval of 57%-98% (p=0.001, twotailed).All original participants were then followed two years and nine months from termination of the study. Efficacy for this follow-up period, estimated from persondays at risk, was 96.6% (95 C.I., 72.2-99.9%) in children under 18 months of age and 100% (95 C.I., 23.5-100%) in children over 18 months of age (PedvasHIB).
  
  Lyophilized PedvaxHIB induced antibody levels greater than 1.0 mcg/mL in children who were poor responders to nonconjugated PRP vaccines (PedvasHIB). In addition, lyophilized PedvaxHIB has been studied in children at high risk of Hib disease because of genetically-related deficiencies [Blacks who were Km(1) allotype negative and Caucasians who were G2m(23) allotype negative] and are considered hyporesponsive to nonconjugated PRP vaccines on this basis. The hyporesponsive children had anti-PRP responses comparable to those of allotype positive children of similar age range when vaccinated
  with lyophilized PedvaxHIB. All children achieved anti-PRP levels of >1.0 mcg/mL (PedvasHIB).

Human Response

• Vaccination Protocol: ProHIBiT ® is indicated for immunization against invasive diseases caused by Haemophilus influenzae type b. ProHIBiT ® may be administered as a booster vaccination at 12 to 15 months of age in children who received primary immunization with Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate) or Haemophilus b Conjugate Vaccine (Diphtheria CRM 197 Protein Conjugate). This vaccine also may be administered as primary immunization at 15 months of age in children who have not received primary immunization with any licensed Haemophilus b Conjugate Vaccine (AAPC 1991). The immunizing dose is a single injection of 0.5 mL given intramuscularly in the outer aspect area of the vastus lateralis (mid- thigh) or deltoid.
• Immune Response: In studies conducted with ProHIBiT ® in several locations throughout the US, the antibody responses of 18- to 26- month- old children were measured, mean antibody levels induced by ProHIBiT ® in children 18 to 20 months of age are 30- fold higher than those induced by polysaccharide vaccines in the same age group. Following immunization of 16 to 24- month- old children with a single dose of ProHIBiT ® , 89% (109/ 123) had antibody levels ³ 0.15 µg/ mL 12 months post- immunization, compared to 93% one month post- immunization (ProHIBiT 2007).
• Side Effects: Side effects associated with a single vaccination of HibTITER include fever, local reactions, rash, diarrhea , vomiting , prolonged crying.

chinchillas Response

• Vaccination Protocol: The 58 chinchillas animals were randomly assigned to three groups (saline [n = 19], dLOS-TT [n = 20], and dLOS-HMP [n = 19]), and a blood sample was collected from the transverse venous sinus of each chinchilla to assess antibody levels. Three days later, the animals were immunized with three doses of the two conjugates or saline (as a control) at 4-week intervals. Blood samples were also collected from all of the chinchillas 14 days after the first and second immunizations, 10 days after the third immunization, and before sacrifice. The animals were anesthetized with ketamine-HCl (30 mg/kg of body weight given intramuscularly) prior to all operative procedures (Gu et al., 1997).
• Immune Response: Three injections of saline did not elicit a rise of LOS antibodies in controls. In contrast, both conjugates elicited significant levels of anti-LOS IgG and IgM antibodies.
• Challenge Protocol: The animals were challenged by injection of 140 CFU of strain 9274 into the right ME 14 days after the last immunization. Both ears were examined daily by otoscopy for evidence of acute OM for 21 days postchallenge. On days 3, 7, 14, and 21 postchallenge, four or five animals from each group were sacrificed by ketamine injection followed by cervical dislocation and the ME fluids from both ears were cultured for bacterial counting (Gu et al., 1997).
• Efficacy: All controls developed OM with culture-positive NTHi effusions up to 21 days postchallenge. In contrast, 60% of chinchillas from both conjugate groups developed OM on day 3, 80% did so on day 7, and 60% did so on day 14. On day 21, no animals in the dLOS-TT group and only 50% of the animals in the dLOS-HMP group showed OM with effusions. The incidence of OM was significantly lower in the dLOS-TT group than in the controls on day 21 and over the whole course. There was no significant difference between the dLOS-TT and dLOS-HMP groups.