What Do The Following Rubella IgG Immunisation Test Results Indicate?

Posted on Thu, 20 Oct 2016

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Thu, 20 Oct 2016 Answered on

Thu, 10 Nov 2016 Last reviewed on

Question : Hi,I had a Rubella IgG done as a part of my immunization tests.But the test came out as "borderline" as in between 0.9-1.1. it says the values above 1 are positive and values below 0.8 are negative. So am I positive for the antibodies??OR should I repeat the test.?? what does Borderline mean??

Answered by Dr. Diptanshu Das (2 hours later)

Brief Answer:
retest after a month or so.

Detailed Answer:
Thanks for asking on Health care magic.

I would ask you why you want to test for rubella antibodies? The importance of rubella is low in males. IgG indicates old immunity. Borderline means that it might still be in development. You should retest after a month or so.

Regards

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Diptanshu Das (7 hours later)

Well,I had to get a Rubella IgG done since it is mandatory for a university that I am applying to in the US. It's a part of my application hence the need for the test..The thing is I have been vaccinated with MMR in my childhood but when I had the test done 2 years ago..it came as negative. I did'nt do anything about it then.But now since i had to test positive in my immunization records, I had a Rubella vaccination(just a single dose) about 2 months ago.I believed that this would solve my problem but still it says borderline,hence i thought i'd ask someone about it....I had the test done on 7/10/2016...Can i repeat it again before 30/10/2016..or should i wait longer??...Why did my test come back negative 2 years ago despite being vaccinated in my childhood..Is it not a live vaccine which is supossed to provide a better immunity than the other killed vaccines???

Answered by Dr. Diptanshu Das (3 hours later)

Brief Answer:
Immunity may take some time to develop

Detailed Answer:
Thanks for writing back.

Immunization can be of two types - active and passive. In case of active immunity the agent (irrespective of whether alive or killed) is injected and the body produces the antibodies in response. The process may take several weeks for the immunity to develop. I cannot say why the initial test had come negative but the subsequent dose that you took two months back, should have taken time to produce some immunity. The immunity might still not have been appreciable and could have lead to borderline results.

You can test before 30.10.16 and see if the results turn positive. If not, discuss with your doctor whether he recommends a booster.

Regards

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar