What is Prevenar?
Prevenar is a vaccine available as a suspension for injection containing parts of the bacterium Streptococcus pneumonite (S. pneumoniae) .
What is Prevenar used for?
Prevenar is indicated for the vaccination of infants and children from two months to five years against diseases caused by S. pneumoniae. These diseases include : sepsis (blood infection), meningitis (inflammation of the membranes surrounding the brain and spinal cord), pneumonia (inflammation of the lungs), otitis media (inflammation of the middle ear) and bacteremia (presence of bacteria in the blood ).
The medicine can only be obtained with a prescription.
How is Prevenar used?
The vaccination program to be administered depends on the age of the child and must be based on official recommendations:
- for infants aged between two and six months, three doses are required. The first dose is usually given at the second month of age, with an interval of at least one month between doses. A fourth (reinforcement) dose is recommended during the second year of life. Instead, when Pevenar is administered as part of a universal infant immunization program (collective and almost simultaneous vaccination of all infants residing in a given area) two doses can be given with an interval of at least two months, followed by a dose of reinforcement between 11 and 15 months of age;
- for infants between the ages of seven and 11 months, two doses are required, with an interval of at least one month between doses. A third dose is recommended during the second year of life;
- for children between 12 and 23 months two doses are required, with an interval of at least two months between doses;
- for children aged between 24 months and five years only one dose is required.
The vaccine should be given to infants by injection in the muscle in the thigh or in the deltoid muscle of the arm for young children.
How does Prevenar work?
Vaccines act by "teaching" the immune system (the body's natural defense system) to defend itself against a disease. When a person is vaccinated, the immune system recognizes the bacterium contained in the vaccine as "foreign" and produces antibodies against it. In the event of exposure to the bacterium after vaccination, the immune system will be able to produce the antibodies more quickly. The body can therefore protect itself from diseases caused by these bacteria.
Prevenar contains small amounts of polysaccharides (a type of sugar) extracted from the capsule that surrounds the S. pneumoniae bacterium. These polysaccharides are purified and subsequently "conjugated" (bound) to a vector to promote better recognition by the immune system. The vaccine is also "adsorbed" (fixed) to a compound containing aluminum to stimulate a better response. Prevenar contains polysaccharides from different types of S. pneumoniae (serotypes 4, 6B, 9V, 14, 18C, 19F and 23F). It is estimated that in Europe they are responsible for about 54% and 84% of invasive infections (extended to the whole body) in infants and children less than two years old, and about 62% to 83 % of invasive infections in children aged between two and five years.
How has Prevenar been studied?
The efficacy of Prevenar in the prevention of invasive diseases caused by S. pneumoniae has been studied in almost 38, 000 infants. Half of the children were vaccinated with Prevenar and the other half with another vaccine, not active against S. pneumoniae . Prevenar was given at two, four, six and 12-15 months of age. The study measured the number of children who developed an invasive disease caused by S. pneumoniae over the course of the 3.5-year study duration. Further studies measured the efficacy and safety of Prevenar in older infants, and the development of antibodies in infants after the two-dose immunization program followed by a reinforcement dose.
What benefit has Prevenar shown during the studies?
Prevenar was effective in preventing invasive diseases caused by S. pneumoniae . During the main study, 49 cases of infection due to serotypes 4, 6B, 9V, 14, 18C, 19F and 23F of S. pneumoniae were observed among the children who were given the control vaccine compared to 3 cases registered among the children who had been vaccinated with Prevenar. Additional studies showed that Prenavar was safe and effective in children up to five years old. In infants, the two-dose immunization program led to the development of antibodies against S. pneumoniae, although at lower levels than in the three-dose program. However, the CHMP considered it unlikely that there will be a difference in the level of protection against S. pneumoniae infections after the reinforcement dose when Prevenar is used as part of a routine immunization program that involves the vaccination of most part of the infants.
What is the risk associated with Prevenar?
The most frequent side effects with Prevenar (seen in more than 1 patient in 10) are vomiting, diarrhea, loss of appetite, local reactions at the injection site (redness, induration, swelling or pain), fever, irritability, drowsiness and restless sleep. For the full list of all side effects reported with Prevenar, see the Package Leaflet.
Prevenar should not be used in children who may be hypersensitive (allergic) to the Streptococcus vaccine or any of the other substances or to diphtheria toxoid (a attenuated toxin from the bacterium that causes diphtheria). As with all vaccines, if Prevenar is given to very premature infants, there is a risk that it causes an apnea (short pause in breathing). Breathing of infants must therefore be checked up to three days after vaccination.
Why has Prevenar been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Prevenar's benefits are greater than its risks for active immunization against invasive disease (including sepsis, meningitis, pneumonia, bacteraemia and acute otitis media) caused by serotypes 4, 6B, 9V, 14, 18C, 19F and 23F of S. pneumoniae in infants and children from two months to five years of age. The Committee therefore recommended that Prevenar be given marketing authorization.
More information on Prevenar
On 2 February 2001, the European Commission issued a marketing authorization valid throughout the European Union to Wyeth Lederle Vaccines SA for Prevenar. The marketing authorization was renewed on 2 February 2006.
The full EPAR for Prevenar can be found here.
Last update of this summary: 02-2008.
