Question about rotavirus vaccine

[Apple_1]

Hi all,

The CDC recommends the first immunization for live vaccines (s.a. MMR, Varicella) begin at 12 months of age. However, rotavirus is also a live vaccine but is administered at 2, 4, and 6 months, and is never administered after 8 months.

I know that the rotavirus vaccine decreases the severity of illness if it is contracted and prevents most rotavirus cases in the US, but theoretically, why would this work before the immune system has matured enough?

---

Members don't see this ad.

 

[Oligodinero]

My understanding is that orally-administered live attenuated vaccines are very immunogenic and induce a sufficient immune response. It wasn't too long ago that oral polio was also given to infants....they only switched to the IPV after polio was eliminated from the Western Hemisphere and vaccine-induced cases of polio were becoming more prevalent as the vaccine strain reverted to wild-type pathogenicity....the vaccine was causing harm.

 

[Apple_1]

Thanks for your response! Yes, I understand that oral vaccines are more immunogenic, and it’s a great point you make about the Salk vaccine being used in infants. But my question still remains why would they be more immunogenic? I guess I’m looking for a pathophysiology response?

This also makes me think of another question; if a child was given IVIG early in life, would we not administer rotavirus vaccine? (In varicella and MMR, the vaccines are delayed for 3-11 months since IVIG administration I believe).

 

[Oligodinero]

Not IVIG.....I think you're referring to passive immunity from maternal antibody transfer across the placenta. I'm not certain as to exactly why, but it seems that live virus inoculation across the gut induces a very robust IgA response which offers protection against fecal-oral pathogens..an Ig-A mediated protective response. Maternally derived antibodies, being IgG, would be less protective against these organisms as they don't concentrate at the GI mucosa and aren't secreted into the gut lumen.

 

[Apple_1]

In my second question, I am referring to IVIG. For example, let’s say an infant was born to a HBV+ mom, and needed IVIG + the HBV vaccine to protect from chronic hepatitis. Because this infant received IVIG, would the baby still receive rotavirus at 2, 4, and 6 mo (or 2 & 4 mo depending on the formulation)? I ask because per my studies some live vaccines like VZV and MMR are delayed after receiving IVIG.

 

[Oligodinero]

I don't know for sure. IVIG is mostly IgG and most adults from whom IVIG is derived likely don't have high circulating titers to Rotovirus.....their immunity likely likes in memory B and T cells. Also the protective antibodies against rotavirus are mostly mucosal secretory IgA, IIRC. So it's probably OK to administer rotovirus vaccine PO to an infant after an IVIG injection...in theory.
MMR and Varicella vaccines typically induce long-lasting protective IgG titers well into adulthood.....so I can appreciate the rationale for not administering those vaccines after IVIG shots.

 

[BigRedBeta]

The other element you are missing is not just immune response but also most common age for severe complications. Rotavirus gastroenteritis is unlikely (though not impossible) to result in hospitalization after a year. When the risk/benefit analysis is done for vaccines, how you choose your outcomes matters. Even if the immune response is incomplete (i'm not saying that it is), if there's a reduction in severe outcomes and attenuated disease course, that still may be worthwhile.

Hep B and Varicella both have specific products that are isolated Immunoglobulin for those conditions so that's not a good example, at least in the US. IVIG for something like HSP or ADEM or Transverse Myelitis would be more likely but all pretty rare infants (all much more common in toddlers). Given that Rotavirus vaccine is only suggested and not a required immunization, I don't think anyone would likely stress about giving it.