This vaccine contains hepatitis B surface antigens, which are proteins on the outer surface of the virus that can be recognized by the immune system. Unlike older versions of the hepatitis vaccine, currently available vaccines (including Comvax) are not made using human blood products. Instead, they are made using recombinant DNA technology. This vaccine is not "live," so there is absolutely no chance that a person could get hepatitis B from it.
This vaccine also contains Hib polysaccharides, which are sugar molecules from the outside coating of the Hib bacteria.
The components of this vaccine "trick" the body into thinking it has been exposed to Hib bacteria and hepatitis B virus, without the risk of being exposed to the actual bacteria or virus. The body produces antibodies that will help fight infection if future exposure occurs.
Some general considerations to keep in mind about Comvax include the following:
- This vaccine is typically given as three doses. Ideally, the first dose is given at two months of age, although it can be given to newborns as young as six weeks old.
- Comvax is injected into a muscle (intramuscularly), usually in the thigh.
- Children can be vaccinated if they have a minor illness, such as the common cold. However, the vaccine should be postponed if the child is moderately or severely ill.
There is only one standard recommended dose for this vaccine (see Comvax Dosage for more information).