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TheGermDoctor, Doctor
Category: Medical
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Experience:  17 years as a physician, Board Certified in both Internal Medicine and Infectious Diseases
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I am living with two people who have just been diagnosed

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I am living with two people who have just been diagnosed with Hepatitis A. Although I practice good hygiene, they do not. I am worried I may have it/get it and have no symptoms yet. I am about to leave to go down to our local health dept. and get vacinated for it so I won't get it. However, the thought occured to me, that if I have already contracted it but have no symptoms yet, that maybe I should be tested for it first. I asked the health dept. about being tested and they said it would take 3 weeks for the results. I figure if I don't alrady have it, if I wait the 3 weeks for the results before being vaccinated, that I could get it by then. Can you tell me if I can get vaccinated at the same time I'm tested and if the results of the test 3 weeks from now are positive, will the vaccine do anything for me? Is there any negative impact from getting the vaccine after I've already contracted it, if that turns out to be the case? Also, what about the immunoglobulin shot. Is there a benefit to this for me?


The incubation for Hepatitis A is on average 25-30 days- it takes this long for symptoms to develop. So if you are housemates with patients with Hepatitis A, you could indeed already be incubating the virus- either from having contracted it from them, or from acquiring it the same place they did.

There have been several studies now that show a benefit in vaccination as "post-exposure " prophylaxis. Giving you the vaccine now, will be as effective as giving immune globulin, but it also will provide long term protection ( if you complete the vaccine series of 2 shots).

The immune globulin is a blood product- with low risk of side effects/ contracting infection, but would only give you short term protection.

As far as testing- I am not sure you may have understood ( or they may have misspoken) - Testing for Hepatitis A antibodies will get a result back within a couple hours- but this will just check if you ALREADY have protection. If you check a Hepatitis A total antibody, and it's positive, you already have pre-existing protection and nothing more needs to be done. If you do not have pre-existing antibodies, then as I noted above it can take 1-2 months for the incubating infection ( if you are infected) to show up- and you should have post-exposure vaccine or immune globulin now to prevent it.

If I saw you- I would consider checking hep A Total antibody and then vaccinate if negative ( and do nothing if positive). But I would give vaccine over immune globulin. Alternatively, one could consider just vaccinating and not testing, if you have been at low risk of prior infection.

Good luck.

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