Vaxem

Active immunisation against invasive disease caused by Haemophilus influenzae type b in children from 2 months of age. This vaccine does not stimulate protection against diseases caused by different Haemophilus Influenzae serotypes and from other meningitis types caused by different pathogen agents.

Haemophilus influenzae type b (Hib) bacteria are surrounded by polysaccharide capsules, which make the bacteria resistant to attack by white blood cells. However, human blood serum contains antibodies, which render the bacteria vulnerable to attack. The vaccine, which is composed of the purified polysaccharide from Hib bacterial cells, stimulates production of anticapsular antibodies and provides active immunity to the Haemophilus influenzae type b bacteria represented by the polysaccharide in the vaccine.

Haemophilus b polysaccharide vaccine, unlike the conjugate vaccine, predominantly stimulates B-cells to produce antibodies. This is known as being T-cell independent and is characteristic of polysaccharide vaccines. The initial stimulation of T-cells followed by stimulation of B cells (known as a T-cell response) is particularly important in young children to ensure adequate and persisting antibody production. Stimulation of T-cells also results in an anamnestic response to future doses of the vaccine and future natural exposure to Haemophilus influenzae type b. The poor T-cell response stimulated by the polysaccharide vaccine is thought to be one reason why the polysaccharide vaccine is not adequately immunogenic in children up to 18 months of age and may not be fully immunogenic in children 18 to 24 months of age. In addition, lack of initial T-cell stimulation probably is the reason that repeat doses of the polysaccharide vaccine do not boost the antibody response consistently.

In clinical studies, concomitant administration of this vaccine with various vaccines containing the following antigens did not affect immune responses to these other antigens: diphtheria and tetanus toxoids, whole cell or acellular pertussis components, polioviruses (live attenuated), hepatitis B, or live attenuated measles, mumps and rubella viruses. As with other vaccines it may be expected that in patients receiving immunosuppressive therapy or patients with immunodeficiency, an adequate immune response may not be achieved. Different injectable vaccines must not be mixed in the same syringe and should be administered at different injection sites.

Very common adverse reactions are tenderness, erythema, induration, unusual crying, irritability, vomiting, diarrhoea, change in eating habits, sleepiness, fever.

No reproductive studies have been conducted in animals since vaccination against Hib in adults is uncommon. There is no accurate information on the safety of this vaccine in pregnancy therefore this vaccine should not be used in pregnancy or during lactation.

In the presence of congenital or acquired immune deficiency, this vaccine may be administered but a protective immune response may not be elicited. Although a limited immune response to the diphtheria toxin component may occur, vaccination with this vaccine does not substitute for routine diphtheria vaccination. This vaccine does not elicit protection against diseases caused by other H.influenzae serotypes and does not protect against meningitis caused by other pathogenic agents. This vaccine should under no circumstances be administered intravascularly.

Vaccines, Anti-sera & Immunoglobulin

This vaccine has a shelf life of 2 years provided that the packaging is integral and the product correctly stored. Do not use the product after the expiry date. This vaccine should be stored and transported at a temperature between 2°C and +8°C.