Haemophilus influenzae type b vaccine

Haemophilus influenzae type b vaccine (Hib) is a prescription medication in the vaccine class.

The Haemophilus influenzae type b vaccine (Hib) is approved to prevent Hib disease in infants and young children. Hib disease is a bacterial infectious disease caused by Haemophilus influenzae and is characterized by symptoms such as meningitis (inflammation around the brain and spinal column), bloodstream infections, pneumonia, arthritis and infections of other parts of the body.

Injections provide the Hib vaccination against Haemophilus influenzae type b(Hib). It is absorbed from the muscle tissue into the bloodstream, which is then transported throughout the body, facilitating the production of antibodies by the immune system. Metabolic and immunological processes ultimately remove it from the body over time.

The common side effects of Haemophilus influenzae type b include redness, pain, swelling, a hard lump at the administered site, fever, fussiness, or irritability in infants and young children.

Haemophilus influenzae type b vaccine is available as a powder for injection.

Haemophilus influenzae type b (Hib)is available in the United States, the United Kingdom, India, Germany, China, Brazil, Japan, Mexico, Canada and Australia

Haemophilus influenzae type b(Hib), belonging to the vaccine class, acts by activating immunity by stimulating the production of endogenously produced antibodies.

Haemophilus influenzae type b (Hib). While this polysaccharide capsule functions as an antigen, unlike other antigens, it fails to stimulate a T-cell response. Because it predominantly stimulates antibody synthesis through a T-cell-independent immunological reaction, the polysaccharide variant of the Hib vaccine leads to limited antibody production. As a result, it is not particularly immunogenic in children under two.

The polysaccharide form is conjugated to a protein, covalently joining the PRP capsule with a protein component to increase the immunogenicity of the vaccine. This combination vaccination attracts T-cells and induces a more powerful immunological response, increasing anti-PRP antibody production.

The length of disease protection is long-lasting (years), although the onset of it is relatively slow.

Haemophilus influenzae type b vaccine is available as powder for injection.

Powder for injection: The Hib vaccine is supplied in two vials, one containing freeze-dried powder and the other a sterile diluent (often a saline solution). After thoroughly combining the powder and diluent, it is generally given.

It is to be administered parenterally, as applicable.

Haemophilus influenzae type b vaccine can be used as follows:

• Protection against Haemophilus influenzae type b (Hib) infections can cause severe illnesses like meningitis, pneumonia, and bloodstream infections, especially in young children.
• Children younger than age 5 years of age who are at the highest risk for infection.
• To reduce the occurrence of otitis media (ear infections) caused by Hib, which can be painful and lead to hearing problems.

Haemophilus influenzae type b vaccine can help support the following health benefits:

• Prevention: The Hib vaccine effectively prevents Haemophilus influenzae type b (Hib) infections in children, reducing the risk of severe diseases caused by Haemophilus influenzae bacterium.
• Otitis media: Otitis media, or middle ear infections, are frequently caused by hib infections in young children. These infections can be painful and damage the auditory system. The Hib vaccination lowers the incidence of ear infections, which improves hearing health and lessens the need for medications.
• Pneumonia: Hib bacteria have been known to cause pneumonia, a lung infection that may cause respiratory distress and complications. The Hib vaccination lowers the risk of pneumonia caused by Hib, enabling healthier lungs and minimizing respiratory problems. Vaccination prevents pain and difficulties with the respiratory system by protecting against pneumonia caused by the Hib bacterium.
• Meningitis: The membranes covering the brain and spinal cord are severely infected by Hib meningitis. Hib-related meningitis, which can result in fatality or irreversible neurological damage, can be effectively prevented by the Hib vaccination. This defence improves the overall health and well-being of immunized children.
• Community Immunity: Widespread Hib vaccination shields individuals and establishes herd immunity. Hib bacterium transmission is significantly reduced when a substantial percentage of the population is immunized. As a result, the community's Hib infection rates are decreased, and unvaccinated people are indirectly protected, including those not medically eligible for vaccination. Herd immunity is facilitated by high vaccination rates, protecting the unvaccinated and lowering Hib infection rates in the community.

Haemophilus influenzae type b vaccine (Hib) is approved for its use in the following clinical indications:

• Children between 6 weeks and 7 years old should have a primary immunization to protect against tetanus, diphtheria, pertussis, hepatitis B, and severe Haemophilus influenzae type B infections.
• It is indicated as a booster dose in paediatric patients aged 15 months to 4 years for active immunization to avoid the spread of invasive disease caused by Haemophilus influenzae type B.
• Individuals who, regardless of their immunization history, have undergone a hematopoietic stem cell transplant.

Parenterally: Haemophilus influenzae type b vaccine (Hib) is available in powder for injection. It should be administered intramuscularly or subcutaneously but advised not to be administered in the GLUTEAL MUSCLE-like buttock areas. Injectable Hib vaccine is typically injected into the muscles of the upper arm or thigh (for infants and young children) as a single-dose injection. It can be only given by a healthcare professional in a hospital setting or during routine immunization programs.

After administration, the healthcare provider will document the vaccination, including the date, time, dose, and injection site.

The dosage and duration of treatment should be as per the treating physician's clinical judgement.

Powder for Injection

ActHIB, Hiberix

10mcg Haemophilus b, 25mcg tetanus toxoid/0.5mL

PedVaxHib

7.5 mcg Haemophilus b PRP, 125mcg Neisseria meningitides OMPC/0.5 mL

Dosage Adjustment for Adult Patients

H. influenzae Type B Immunization

Routine immunization is not advised for otherwise healthy individuals.

Asplenia

Indicated for adults who have functional or anatomic asplenia (including sickle cell disease) or have undergone elective splenectomy

If the Hib vaccine has not been received previously, one dose should be given.

HIB vaccination should be given ≥14 days prior to splenectomy

Complement deficiency

Indicated for adults with recurring complement component deficiencies

If the HIB vaccine has not been received previously, one dose should be given.

Post-HSCT Recipients

Regardless of any vaccination history, recipients of a hematopoietic stem cell transplant (HSCT) should receive a 3-dose immunization schedule 6 to 12 months following a successful transplant.

Separate dosages by at least 4 weeks.

Haemophilus influenzae type b vaccine is available as powder for injection.

Haemophilus influenzae type b vaccine should be used to prevent Haemophilus influenzae type b bacterial infection along with no appropriate dietary restrictions. Consuming regular foods and drinks before and after receiving the vaccine is safe.

However, it is always recommended to maintain a balanced and healthy diet to support overall immune system function, which can boost the effectiveness of vaccines.

The dietary restriction should be individualized as per patient requirements.

Haemophilus influenzae type b vaccine (Hib) may be contraindicated in the following conditions: -

• Anaphylaxis (H. influenzae type B- or tetanus toxoid-containing vaccine or any component of the vaccine)
• Allergic to natural rubber latex
• Encephalopathy (brain disease or disorder)
• Guillain-Barré Syndrome (GBS)

The treating physician must closely monitor the patient and keep pharmacovigilance as follows.

• Children with weak immune systems, such as those who have HIV infection or cancer or are taking certain drugs, may not respond as well to the Hib vaccine and may consult a healthcare professional who might suggest modifying the vaccine schedule or giving additional doses to these people to improve protection.
• It may be advisable to postpone the vaccination if the child is currently experiencing a fever or a moderate to severe sickness.
• Healthcare professionals should assess the risk and benefits of the vaccination in case of any severe allergic reaction or a severe reaction to a previous dose of the Hib vaccine.

Caution is advised when consuming alcohol with Haemophilus influenzae type b vaccine (Hib).

There is no sufficient scientific evidence regarding the use and safety of the Haemophilus influenzae type b vaccine in the breastfeeding population.

There is no sufficient scientific evidence traceable regarding the use and safety of the Haemophilus influenzae type b vaccine in the pregnant population.

There is no sufficient scientific evidence traceable regarding the use and safety of the Haemophilus influenzae type b vaccine in concurrent use with any particular food.

The adverse reactions related to Haemophilus influenzae type b vaccine can be categorized as

• Common: Pain, redness, swelling, hard lump at the injection site, irritability and low-grade fever.
• Less Common: Loss of appetite and GI symptoms like nausea or diarrhoea.
• Rare: Seizures, high fever (over 105°F or 40.5°C) and allergic reactions.

The clinically relevant drug interactions of the Hib vaccine are briefly summarized here:

• Immunosuppressants- Drugs like prednisone or cyclosporine suppress the immune system and may reduce the effectiveness of Hib vaccine.
• Antibiotics: Antibiotics, like rifampin, can interfere with the effectiveness of the Hib vaccine. Rifampin is often used to treat certain bacterial infections, including tuberculosis. It is recommended not to take it concurrently and advised to adjust the vaccination schedule or consider additional doses of the Hib vaccine.
• Other Vaccines: The Hib vaccine is often administered alongside other childhood vaccines, such as the DTaP (diphtheria, tetanus, and acellular pertussis) vaccine. To reduce any risk, medical professionals frequently adhere to vaccination regimens considering the time and space of vaccines.

The common side of Haemophilus influenzae type b vaccine (Hib) includes the following-

• Tenderness, rash, pain, soreness, warmth, swelling, or hard lump at the site where the shot was given.
• Low or high fever.
• Irritability
• Joint pain, body aches.
• Drowsiness
• Vomiting.
• Fever
• Loss of appetite
• Continuous crying for three hours or longer in case of infants and children
• Seizures
• Unexpected weakness or fatigue
• Prolonged, unusual, high-pitched crying
• Sleepiness
• Infections of the ear
• Upper respiratory tract infection

The use of the Hib vaccine should be prudent in the following group of special populations.

• Pregnancy: There is no sufficient scientific evidence traceable regarding the use and safety of the Haemophilus influenzae type b vaccine for pregnant populations.

• Paediatrics: Paediatricians recommend the Hib vaccination to avoid serious illnesses, including meningitis and pneumonia. Immunization in children also boosts herd immunity, improves children's general health, and lowers child mortality, adverse effects, and costs associated with healthcare.

Dosage Adjustment for Paediatric Patients

H. influenzae Type B Immunization

IM injection is recommended for children aged 2 to 15 months and up to 5 years for routine immunization and catch-up vaccination.

Primary series (2 or 3 doses): 6 weeks - 12 months

Booster: 3rd or 4th dosage administered between 12-15 months

PRP-OMP

Polyribosylribotol phosphate (PRP)-conjugated outer membrane protein (OMP) complex from Neisseria meningitis; monovalent vaccinations

PEDvaxHIB: 2 and 4 months (primary series) followed by booster dose between 12–15 months.

PRP-T

Polyribosylribotol phosphate (PRP) conjugated to tetanus toxoid (T); monovalent vaccines.

ActHIB, Hiberix: 0.5 mL Intramuscularly as a 4-dose a series of 2, 4, and 6 months (primary series) and between 12 to 15 months (booster)

Combination of vaccines

PRP-OMP-HepB (Comvax): 2 and 4 months (primary series) followed by booster dose between 12 to15 months

DTap-IPV/PRP-T (Pentacel): 2, 4, and 6 months (primary series) followed by booster dose between 12 to15 months

MenCY-PRP-T (MenHibRix): 2, 4, and 6 months (primary series); 12 to15 months (booster)

Considered fully immunized if,

An initial minimum of 1 dose after 14 months, 2 doses between 12 and 14 months old, or

More than 2 doses in the first year of life, then a booster when the child is older than 1 year.

Immunosuppressed individuals.

Consider administering if a patient is 5 years or older, not vaccinated and is immunosuppressed, having one of the following conditions: HIV, leukaemia, sickle cell disease, or functional or anatomical asplenia.

Dosing Considerations

PRP-T: Polyribosylribotol phosphate conjugated to tetanus toxoid

OMP: Outer membrane protein complex from Neisseria meningitidis

A minimum age of 6 weeks old is required for vaccination of PRP-T (ActHIB), DTaP-IPV/Hib (Pentacel), and Hib-MenCY (MenHibrix), or PRP-OMP (PedvaxHIB, Comvax)

PRP-T (Hiberix) vaccinations need a minimum age of 12 months.

ActHIB: Reconstituted with 0.4% NaCl diluent is recommended for active immunization of children between the ages of 2 and 5 to avoid the spread of invasive Haemophilus influenzae type B disease.

TriHIBit: TriHIBit vaccine, which is made by reconstituting ActHIB with Tripedia (DTP) vaccine, is recommended for use in children between the ages of 15 and 18 months for the active immunization against invasive illness caused by Haemophilus influenzae type b and diphtheria, tetanus, and pertussis.

• Geriatrics: There is no sufficient scientific evidence traceable regarding the use and safety of the Haemophilus influenzae type b vaccine for geriatric populations.

• Lactating mothers: There is no sufficient scientific evidence traceable regarding the use and safety of Haemophilus influenzae type b vaccine for lactating mothers populations.

Dosage Adjustment in Kidney Impairment

There are no specific dosage adjustments provided.

Dosage Adjustment in Hepatic Impairment

There are no specific dosage adjustments provided.

Overdosage of Haemophilus influenzae type b (Hib) vaccine rarely occurs as the healthcare professionals administer it according to specific or precise dosing guidelines.

There is no specific antidote or treatment for excessive intake of Hib vaccine. Medical attention should be sought immediately when an overdose is suspected, followed by monitoring any adverse effects or allergic reactions. Supportive therapy should also be given, addressing any symptoms that persist or worsen. Physical treatment might be added if necessary.

Pharmacodynamics of Haemophilus influenzae type b(Hib) vaccine:

The Haemophilus influenzae type b vaccine has a physiological mechanism that plays a role in its pharmacodynamics. When administered, the vaccine components from the Hib bacteria activate the immune system. The Hib polysaccharide capsule is the target of B lymphocytes that are stimulated to produce antibodies, predominantly IgG. The immune system develops a memory response as a result of time, making it more likely that it will be able to promptly identify and eliminate the Hib germs if they ever infect the body. This adaptive immunity offers long-lasting protection, particularly in young children who are most at risk, avoiding invasive Hib infections. The effectiveness of the vaccination is based on its capacity to strengthen the immune system for an effective defence against Hib, thus lowering the chance of serious infections.

Pharmacokinetics of Haemophilus influenzae type b(Hib) vaccine

• Absorption: The Haemophilus influenzae type b(Hib) vaccine, which contains Hib bacterium, is given intramuscularly, allowing it to be absorbed from the muscle tissue into the bloodstream.

• Distribution: After absorption, the vaccine's active ingredients pass through the bloodstream and reach the lymph nodes and other immune-system organs.
• Metabolism: Unlike drugs and nutrients, the vaccine does not undergo metabolic processes. Instead, it serves as a trigger for the immune system to recognize and respond to the Hib bacterium.

• Elimination: The vaccine is eventually eliminated from the body through normal metabolic and immune system processes. The body's immune memory retains information about Hib, enabling it to respond effectively if it is exposed to the actual bacterium in the later period.

• Bavdekar, Ashish et al. “Clinical study of safety and immunogenicity of pentavalent DTP-HB-Hib vaccine administered by disposable-syringe jet injector in India.” Contemporary clinical trials communications vol. 14 100321. 9 Jan. 2019, doi:10.1016/j.conctc.2019.100321
• Sharma, Hitt et al. “A phase I, open-label, clinical study to assess the safety and immunogenicity of indigenously developed liquid (DTwP-HepB-IPV-Hib) hexavalent combination vaccine in healthy toddlers aged 16-24 months.” Human vaccines & immunotherapeutics vol. 18,6 (2022): 2146435. doi:10.1080/21645515.2022.2146435

• Inform the caregivers of the schedule for administering the Hib vaccine doses, including the specific ages they should be given.
• Assure caregivers that Hib immunizations are generally safe, with only minor, short side effects. Encouraging them to immediately report any unexpected or severe responses to the healthcare physician and, whenever applicable, to use reporting systems like the Vaccine Adverse Event Reporting System (VAERS)
• Inform caregivers of the recommended immunization schedule, which usually consists of two or three doses, depending on the vaccine brand. Also, mention the ages at which the doses should be administered and give the Vaccine Information Statements, which must be disclosed before immunization by the National Childhood Vaccine Injury Act of 1986 about the Centres for Disease Control and Prevention (CDC) website (www.cdc.gov/vaccines), these resources are freely accessible.

https://www.cdc.gov/vaccines/vpd/hib/hcp/about-vaccine.html

https://www.ncbi.nlm.nih.gov/books/NBK553112/

Kelly DF, Moxon ER, Pollard AJ. Haemophilus influenzae type b conjugate vaccines. Immunology. 2004 Oct;113(2):163-74.

http://www.cdc.gov/vaccines/schedules/hcp/index.html