Acute and/or Chronic infection despite being vaccinated against hepb, possible or not?


So it is possible that someone can be acute infected or become chronic infection despite being vaccinated against hepb ? Are there real life cases for this to be the case ?


Only if the vaccine was faulty. I haven’t heard of any cases thou.
I do know those that are vaccinated are supposed to check if the vaccine is effective.
@hepb1 @Bansah1 @ThomasTu

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Hi @hepb1,

There are two possibilities that can make this occur:

  1. That despite vaccination, there are no anti-HBs antibodies produced. This can be checked by testing your antibody levels and they are high enough. If they aren’t, then you can get booster vaccinations to try to increase it. About 90-95% of people given the vaccine will respond well, but some people will not raise antibodies.

  2. That despite vaccination and anti-HBs levels at protective levels, infection still occurs. There are some reports of “vaccine-escape mutants”, that is HBV that have changes that cannot be recognised by the anti-HBs antibodies. As far as I know, these are exceedingly rare, but there are a couple of case reports of this happening (e.g., Hepatitis B surface antigen escape mutations: Indications for initiation of antiviral therapy revisited - PMC).

Hope this helps,


Hi @ hepb1
Your question is interesting about the complex and mysterious of hepatitis B virus.As @ Thomas Tu mentioned about the case reports of “vaccine- escape mutants “ which is rarely occurred. It’s due to the fact that CHB patients who have “immune escape mutants “ from natural occurring or selective pressure eg. from antiviral drug ;mostly have low HBV DNA mutant viremia ,so the chance of horizontal transmission to HBV vaccinated persons rarely occur except for these CHB patients are in immunosuppressive stages in which there is increased viral replication resulting in high HBV DNA mutants viremia.

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I don’t know the full history here. Some people have vaccination against HBV without first testing that they do not have HBV. In these cases, the vaccination would be useless. I think in regions with high prevalence of HBV infection, it may be wise to have a test for HBV before vaccination.


Hi @hepb,
Great question. I agree with @ThomasTu and what others have shared. Just wanted to add to the conversation. As @Stephenw was saying that is very true. For instance in the US when you are doing lab work for employment they screen for HBsAb (antibodies) they do not screen for surface antigen (HBsAg). If HBsAb is negative they vaccinate you. That was the case for me with 2 different companies, I never knew my status when this happened and because the companies did not test for (HBsAg) they provided the vaccines which did not do anything since I had the virus already. This gives a lot of false hope and people find out later they are positive and wonder what happened. As it was in my case. I think the best way to avoid this is to run both ABsAg and HBsAb tests, then determine what to do next.

Also, some HIV patients have trouble developing immunity for HBV through vaccination. I think this has to do with either CD4/CD8 issues. So here there is a possibility to get infected if exposed even after vaccination because the person might not develop immunity/antibodies because of their HIV. There are some people who only took the first shot in their vaccine series and never completed the rest. It is highly likely that these people will not develop any antibody or immunity since they only had one shot out of 3. It is believed that completing the entire series either the 3 or 2 shots gives one a better chance of developing antibodies and the individual considered fully vaccinated.

Finally, some people with suppressed immune systems (cancer patients on chemo or other immunosuppressive medications) might have trouble developing immunity or antibodies as well after HBV vaccination.

Even though these cases can be rare, there are possible instances for this to happen. Therefore, it is advisable to check one’s tithers a few months after receiving the last dose of vaccine to make sure the person have developed enough antibodies against HBV. I hope this is helpful to the conversation. Thanks, Bansah1.