Titre: Variant spelling of “titer” — the degree of dilution of a substance such as an antibody, reflecting the strength of the solution. Americans spell it “titer” while the English spell it “titre,” French for “title,” derived from the Latin “titulus,” an inscription or label.

A titer is a laboratory test that measures the presence and amount of antibodies in blood. A titer may be used to prove immunity to disease. A blood sample is taken and tested. If the test is positive (above a particular known value) the individual has immunity.

The greater the concentration of the specific antibody in the serum sample, the higher the titer. For example, a titer for an influenza hemagglutination inhibition assay of 1:10 would be very low; a titer of 1:320 would be high. A low or undetectable titer indicates very little antibody present in the serum.

Titers are blood tests that check your immune status to vaccinations or diseases you may have received in the past. If you’re titers results are positive, it means that you have adequate immunity to a particular infectious disease.

The normal values of an antibody titer depend on the type of antibody. If the testing is done to detect autoantibodies, the normal value should essentially be zero or negative. In the case of testing the efficacy of a vaccine, the normal test result depends on the definite value that is specific for that immunization.

The “titer” is the measurement of the amount of a substance in a solution. The titer indicates the number of times a solution can be diluted and still contain detectable amounts of a particular molecule.

Certain diseases are more likely to have certain patterns. The higher the titer, the more likely the result is a “true positive” result, meaning you have significant ANAs and an autoimmune disease. For example, for a ratio of 1:40 or 1:80, the possibility of an autoimmune disorder is considered low.

The titer of a virus stock can be calculated in plaque-forming units (PFU) per milliliter. To determine the virus titer, the plaques are counted. To minimize error, only plates containing between 10 and 100 plaques are counted, depending on the size of the cell culture plate that is used.

The antibody titer score is generated by the number of times the scientist can dilute a patient’s serum and still be able to detect the presence of antibodies. Titers of 1:80 and 1:160 were categorized as low titers; 1:320 moderate; and 1:960 or ≥ 1:2880 were high.

A titer of 1:160 or above is commonly considered a positive test result. Other conditions with ANA associations include Crohn’s disease, mononucleosis, subacute bacterial endocarditis, tuberculosis, and lymphoproliferative diseases.

Definition. Antibody titer is a laboratory test that measures the level of antibodies in a blood sample.

Low Titer Type O Whole Blood means the complete product contains Type O red blood cells and plasma containing low levels of antibodies making it safe to transfuse to a patient with any blood type. There are Anti-A and Anti-B antibodies present in the plasma of type O donors.

Titer tests are among the tools that dog owners and veterinarians can use to help minimize the risks of both infectious diseases and unnecessary vaccinations. A titer test is an antibody blood test that can tell you if a previous vaccine is still protecting your dog’s immune system.

A titer test is a measure of antibodies in the blood, providing a check of disease immunity. The results of a titer test then allow a clinician to determine whether a vaccination is required. A titer test involves a simple blood draw. The sample is analyzed, and results are returned within 24 to 72 hours.

If you are unsure if you have had all the recommended immunizations, you can find out through an Immunization Titer Test. These tests measure the antibodies in your blood to determine if you have immunity to a disease or if a vaccination may be required.

A three-year interval is appropriate for the majority of adult dogs and cats when quantitative tests are used. The manufacturers of in-clinic (“yes/no”) screening tests recommend they be used annually. A titer test within the first 6 months of life and again at one year is appropriate for puppies.

Blood Testing A blood test can provide proof of immunity, which helps you avoid getting unneccessary vaccines. See our information sheet: Testing for Immunity to Vaccine-Preventable Diseases.

The MMR Titer is a blood test that checks if you are immune to Measles, Mumps and Rubella. It measures your antibody levels to get a sense for whether your immune system has the capability to respond to an infection with one of these diseases.

Immunizations

Immunizations, Titers and TB tests	Cost per Shot
Hepatitis A Titer	$37
Hepatitis B Titer	$14
Varicella Titer	$13
MMR Titer Measles/Mumps/Rubella	$41 $13/$13/$15

Titers & immunity testing. MinuteClinic® providers are trained to perform titer testing to confirm immunity. Your MinuteClinic provider will review your medical and vaccination histories, discuss any symptoms and order the appropriate lab tests.

13.5-16.4 AU/mL: Equivocal – Repeat testing in 10-14 days may be helpful. 16.5 AU/mL or greater: Positive – IgG antibody to measles (rubeola) detected, which may indicate a current or past exposure/immunization to measles (rubeola).

If a college student or other person at increased risk of exposure cannot produce written documentation of either immunization or disease, and titers are negative, they should receive two doses of MMR.

How much do vaccines cost at CVS?

In-demand vaccines	Retail costs
High-dose flu vaccine	$69.99
Shingles vaccine	Costs may range from $180 to $200 per dose. Call your local CVS Pharmacy for the exact cost.
COVID-19 vaccine	Free
Tdap (tetanus, diphtheria, and pertussis)	$77

On MDsave, the cost of a Hepatitis B Surface Antibody ranges from $10 to $43.

The first and second dose should be separated by at least 4 weeks. Serologic testing should be repeated 1 month after the last dose. If the results remain subtherapeutic or negative, the person is considered a nonresponder. No further immunizations are required after the series has been repeated.

Has a parent, brother, or sister with a history of immune system problems. Has ever had a condition that makes them bruise or bleed easily. Has recently had a blood transfusion or received other blood products. You might be advised to postpone MMR vaccination for 3 months or more.