A titer test is a blood test that can help determine whether a child or adult has developed immunity and whether he or she needs a vaccine. It measures the amount of antibodies - proteins in a person's immune system which determines whether there is enough to adequately fight the disease.
This kind of test is especially useful to parents who want to make sure their child is protected from diseases such as measles, mumps, rubella and chickenpox but would like to avoid the second round of vaccines - the boosters for these diseases while following an alternative vaccination schedule.
Having this test done is also useful if parents have skipped some shots, but shots are required by law or school. This test can be done to demonstrate immunity.
Although he believes this kind of test can be very useful, Dr. Sears does not recommend checking titers for babies or toddlers because the likelihood of a young child having developed immunity without vaccination is very unlikely.
Vaccines contain inactivated forms of bacteria or viruses that still retain the characteristic antigens - bacteria or virus' which helps build antibodies to fight against these illnesses. It's not that vaccines produce the antibodies to fight these antigens, but rather, they stimulate your body to produce antibodies against that antigen - bacterial or viral.
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As a result, some kids still have an adequate supply of antibodies made by their immune systems from their first round of vaccines. Alternatively, antibodies are also made by exposure to these diseases.
The test may turn out to be positive, indicating immunity as a result of:
Elizabeth Cohen, senior medical correspondent for CNN's Health, Medical and Wellness unit and author of The Empowered Patient
, suggests checking “titers” (blood immunity levels) for various shots before doing boosters. She states:
"Some kids don’t need some of the booster shots at age 5 years because their original infant series may still be working just fine. While this is a costly and time-consuming approach, some parents prefer it instead of automatically getting all the boosters."
This kind of test can be used for a child or adult and the protective level is the same regardless of age.
If you are a mom or dad who prefers to limit vaccines, administering as few as possible to your child, and follow an alternative vaccination schedule a titer test can be a very useful tool to determine immunity.