Thimerosal Content and Other ConcernsMMRV does not contain thimerosal, a mercury-containing preservative. People who are concerned about exposure to this substance can be confident that this vaccine does not even contain trace amounts of it. Some people are also concerned about the aluminum content of vaccines. MMRV also does not contain any aluminum.
This vaccine is grown in animal and human fetal components. Specifically, parts of the MMRV vaccine are grown in chick embryo cells, fetal bovine (cow) serum, and a cell line developed from an aborted human fetus.
How Does MMRV Work?MMRV is a live attenuated vaccine. This means that it contains living viruses, which have been altered in such a way as to prevent them from actually causing diseases. However, the body's immune system still responds to the viruses, providing future protection from the diseases.
In general, live vaccines provide better protection from infections compared to other types of vaccines, but can actually cause the diseases in rare cases, particularly in people who have weakened immune systems.
When and How to Take ItSome general considerations with the MMRV vaccine to keep in mind include the following:
- This vaccine can be given in place of the individual MMR and varicella vaccines, both of which are usually given as two doses each. Typically, the first dose would be given at age 12 to 15 months, and the second dose would be given at 4 to 6 years of age.
- Because of the increased risk for fever and febrile seizures (seizures caused by fevers) in children 12 to 23 months of age, it is generally preferred to give the first MMR and varicella vaccines separately instead of using MMRV. Giving them separately has a lower risk for such problems. Therefore, this vaccine will typically be used primarily for the second dose only (in children 4 to 6 years of age).
- As with other live vaccines, MMRV is injected subcutaneously (just under the skin), preferably on the upper arm.
- Children can be vaccinated if they have a minor illness, such as the common cold. However, the vaccine should be postponed if the individual is moderately or severely ill.