I have some questions about my vaccination status & immunity

I’m currently undergoing the 2 dose Heplisav B vaccine and will be able to receive my 2nd dose early Jan then will check 1-2 months later for immunity as my partner is a carrier.

I was curious to know a few things…

For starters, if I gain immunity, I understand that over time immunity will decrease. Is there a chance that, as I get older, I’ll be unable to regain immunity if my titer levels fall below the protective levels and I try to get boosted or revaccinated? I read that the vaccine isn’t as effective for older individuals and effectiveness starts to decrease at 40 years old so that concerns me a bit about the prospects of a long term relationship with someone whose a carrier.

Secondly, how fast do titer levels decrease? I plan to get my levels checked maybe 2x a year but what if I get them checked in like June and I’m fully protected, but by July they’ve gone down below the protective levels. Is it possible for them to decrease so suddenly and quickly? Should I get them checked more then just 2x a year?

Dear @Anon2023 ,

In general responsiveness to all vaccines declines SLOWLY as we age but most people still still respond well to vaccination even over the age of 60. Heplisav has a new adjuvant which does a better job in provoking the immune response to HBsAg compared to traditional adjuvants used in older vaccines like TwinRx or Energix-B. A recent study comparing anti-HBs responses to Heplisav and Energix-B can be found at https://www.sciencedirect.com/science/article/pii/S0264410X23004206#f0005

Your immunity (anti-HBs) produced by this vaccine will most likely be strong at your check two months after receiving your second dose will show. This immunity will experience most of its decline over the first few years and then decline more slowly thereafter. This decline should not be cause for concern unless it dips below 10 mIU/mL. In most people, this does not happen or it takes decades. The anti-HBs test is relatively cheap so if testing twice a year provides you some additional comfort there is no harm in doing this. Revaccination with Heplisav or another excellent, recently approved vaccine (Prehevbrio) can be done if your anti-HBs falls below 10 mIU/ml.



Hi @availlant

Thank you for your response. OK - that makes sense. I was worried because I was vaccinated at birth and now (at 28) I’m no longer immune. Although, I have no idea when I become no longer immune. The only reason I checked was bc I met my partner whose a HepB carrier. I suppose the alternative to this could also be that upon birth after vaccination, I never became immune in the first place.

I was worried that perhaps I would get re-vaccinated, then again loose immunity over the years, and ultimately be unable to regain it as I get older.

And that’s good to know about the slow decline in immunity, I was worried that I would get my titers checked one day, then overnight I would dip below the 10mIU/ml mark and not realize it until my next check months later but it seems like that can’t be the case and if I start to hover around lower #s, my doctor would, hopefully, recommend getting boosted

1 Like