Titer testing, laboratory evidence of immunity, is available for some vaccines and in some situations.
Vaccine Titer Testing
With titer testing, you do a blood test to check your antibody levels, which can help determine if you are immune to a specific disease, like measles or chicken pox.
Titer testing is sometimes recommended to confirm the immunity status of:
- healthcare workers
- pregnant women – rubella and hepatitis B
- internationally adopted children
- children and adults with lost vaccine records
While not available for all vaccines, like Hib and pertussis, when necessary, you can check titers for MMR, hepatitis A, hepatitis B, diphtheria, tetanus, and varicella.
Should you get titer testing just in case your child is immune from an asymptomatic infection? While it is true that many viruses and bacteria can cause infections without symptoms, it is extremely unlikely that your child would have had a vaccine-preventable disease without symptoms, considering most are at low levels.
Titer testing to avoid a second MMR vaccine is also not recommended. Although the second MMR vaccine is technically not a booster shot, if your child is negative to any of the three components of the vaccine, then he will still need the second shot.
Is there a downside to doing vaccine titer tests?
“Commercial antibody assays, particularly the LA test, may not be sensitive enough to detect vaccine-induced antibody in some recipients.
Because of the potential for false-negative serologic tests, routine postvaccination serologic testing is not recommended.”
Immune response to varicella vaccine: infection versus vaccine response
Many people who have negative titer tests may still be immune because they have a retained anamnestic potential, instead of being a nonresponder to the vaccine or losing their immunity.
And then there is the pain and cost of doing a blood test.
Also, if titer testing is negative, even if it is a false-negative, you will have to get a vaccine anyway, which is why most doctors and parents opt for getting kids vaccinated and skipping titer testing unless it is necessary.
More on Vaccine Titer Testing
- How Often Should You Do Vaccine Titer Testing?
- Titers for Vaccine vs Natural Immunity
- How Do You Know If You Have Measles Immunity?
- Do You Need Another Dose of the MMR Vaccine?
- Seroconversion after measles or MMR vaccine
- CDC – Guidance for Evaluating Health-Care Personnel for Hepatitis B Virus Protection and for Administering Postexposure Management
- CDC – Pinkbook – Varicella
- Prevention of Measles, Rubella, Congenital Rubella Syndrome, and Mumps, 2013: Summary Recommendations of the Advisory Committee on Immunization Practices (ACIP)
- Immune response to varicella vaccine: infection versus vaccine response