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Can Twinrix Vaccination Cause False Positive For Hepatitis A?
Question: so my blood work tested positive for hep a. it says it can be a false positive if previously immunized. I had twinrix years ago could that still show a false positive in my blood? how long could I read a false positive for?
Brief Answer:
Information
Detailed Answer:
Hello XXXXXXX
If you had the full series of Twinrix vaccinations then you will always test positive for Hepatitis A and likely also for Hepatitis B as well.
The vaccination causes your body to produce antibodies against the Hep A and B viruses. If the test you had detects antibodies (rather than the virus itself), then it will detect the antibodies you made against the vaccine, which means you are immune to Hepatitis A.
Regarding how long your immunity (and false positive) will last: Theoretically, it may give lifetime immunity, however it has not been around long enough to test that.
A Canadian study of Twinrix duration of effectiveness stated that when tested at 15 years after the vaccination series it was still effective against Hepatitis A virus (HAV):
[From GlaxoSmith Kline - manufacturer of Twinrix]
"In two long term clinical studies conducted in adults, 15 years after the primary vaccination with TWINRIX®, the anti-HAV seropositivity rates were 100% in both studies and the anti-HBs seroprotection rates were 89.3% and 92.9% respectively in study HAB-142 (LT-ATP, n=28) and in study HAB-147 (LT-ATP, n=28)."
So it is fair to say that if you had Twinrix, it would be expected for you to have antibodies (false positive for the actual infection) and this immunity may be lifelong, although we can't say for sure yet just how long it will last.
I hope this information helps. Please let me know if I can provide further information.
Information
Detailed Answer:
Hello XXXXXXX
If you had the full series of Twinrix vaccinations then you will always test positive for Hepatitis A and likely also for Hepatitis B as well.
The vaccination causes your body to produce antibodies against the Hep A and B viruses. If the test you had detects antibodies (rather than the virus itself), then it will detect the antibodies you made against the vaccine, which means you are immune to Hepatitis A.
Regarding how long your immunity (and false positive) will last: Theoretically, it may give lifetime immunity, however it has not been around long enough to test that.
A Canadian study of Twinrix duration of effectiveness stated that when tested at 15 years after the vaccination series it was still effective against Hepatitis A virus (HAV):
[From GlaxoSmith Kline - manufacturer of Twinrix]
"In two long term clinical studies conducted in adults, 15 years after the primary vaccination with TWINRIX®, the anti-HAV seropositivity rates were 100% in both studies and the anti-HBs seroprotection rates were 89.3% and 92.9% respectively in study HAB-142 (LT-ATP, n=28) and in study HAB-147 (LT-ATP, n=28)."
So it is fair to say that if you had Twinrix, it would be expected for you to have antibodies (false positive for the actual infection) and this immunity may be lifelong, although we can't say for sure yet just how long it will last.
I hope this information helps. Please let me know if I can provide further information.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
this is my blood work. I just got a job at the hospital so I am worried it will effect it.
Brief Answer:
I wouldn't worry about this effecting your employment status.
Detailed Answer:
I looked at your lab results and what is positive is antibody IgG. This is means that you either had an infection in the past or were immunized (and it states that below the result as well). In your case, of course it is positive because you are immune to Hep A from your vaccine series.
So I don't think there is anything to worry about here. Even if it were positive from a previous infection, IgG does not represent a current active infection (that would be IgM). My guess is they ordered this test to see if you are immune (which you are), rather than to see if you have a current infection and are contagious (for which they would order IgM).
If you can provide proof of the Twinrix, I'm sure that would satisfy any questions, but I don't think there will be any problem either way.
Does that make sense to you? I think they are testing whether you are immune (so you won't pick up Hep A from patients) rather than wether you are contagious with it. This test shows immunity, nothing else.
Did they also test Hep B antibody? That would be a more concerning thing for a health care worker than Hep A, which is a limited gastrointestinal infection.
I wouldn't worry about this effecting your employment status.
Detailed Answer:
I looked at your lab results and what is positive is antibody IgG. This is means that you either had an infection in the past or were immunized (and it states that below the result as well). In your case, of course it is positive because you are immune to Hep A from your vaccine series.
So I don't think there is anything to worry about here. Even if it were positive from a previous infection, IgG does not represent a current active infection (that would be IgM). My guess is they ordered this test to see if you are immune (which you are), rather than to see if you have a current infection and are contagious (for which they would order IgM).
If you can provide proof of the Twinrix, I'm sure that would satisfy any questions, but I don't think there will be any problem either way.
Does that make sense to you? I think they are testing whether you are immune (so you won't pick up Hep A from patients) rather than wether you are contagious with it. This test shows immunity, nothing else.
Did they also test Hep B antibody? That would be a more concerning thing for a health care worker than Hep A, which is a limited gastrointestinal infection.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
I hope my doctor has records because they had no records of shots because they switched systems they said and I had to contact Canada health. on my Canada health it doesn't say I had twinrix but I know 100% I did. I am neg for hep B
Brief Answer:
Thoughts on this.
Detailed Answer:
That is unfortunate that you are negative for Hepatitis B antibodies. The Twinrix is more effective for Hep A, but it is usually quite effective for Hep B too. Unless they did a different kind of test for Hep B than they did for Hep A which distinguished current from past infection/immunity. That is a possibility.
I wouldn't worry about the positive IgG Hepatitis A results. It just shows you are immune.
Thoughts on this.
Detailed Answer:
That is unfortunate that you are negative for Hepatitis B antibodies. The Twinrix is more effective for Hep A, but it is usually quite effective for Hep B too. Unless they did a different kind of test for Hep B than they did for Hep A which distinguished current from past infection/immunity. That is a possibility.
I wouldn't worry about the positive IgG Hepatitis A results. It just shows you are immune.
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Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
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