Immune Response to Rubella Vaccine Varies by Race, Ethnicity
By Megan Brooks
NEW YORK - A new study finds "consistent" evidence for racial/ethnic differences in humoral immune response to rubella vaccination, say researchers with the Mayo Vaccine Research Group, Mayo Clinic, Rochester, Minnesota.
Individuals of African descent have significantly higher rubella-specific neutralizing antibody levels relative to individuals of European descent and/or Hispanic ethnicity (p<0.001), Dr. Gregory A. Poland and colleagues reported online February 13 in the journal Vaccine.
In an interview with Reuters Health, Dr. Poland said, "We make (vaccine) policy, of course, at the population level. That's a paradigm that seems right and even self-obvious to us. But as we enter into the era of personalized medicine that paradigm is starting to fade away."
"For example, if you come here to the Mayo Clinic for treatment of resistant hypertension or depression or certain malignancies, your treatment is individualized to you based on your genomics. There are people that carry some genes that if we gave them the standard dose of chemotherapy it would kill them. There are others that carry certain genes that if we don't double the dose it does them no good," he explained.
"Nobody has applied that paradigm to vaccine responses. Our group has been pushing the concept of individualized vaccinology or what we call vaccinomics," Dr. Poland said.
He and his colleagues assessed associations between race, ethnicity, and gender, and rubella-specific neutralizing antibody levels in two independent, large, racially diverse cohorts involving a total of nearly 2000 healthy people.
The results, they say, "clearly demonstrate significant differences" in the neutralizing antibody responses two to six years after rubella vaccination in different racial groups with "consistently higher titers observed in individuals of African descent, compared to individuals of European descent and/or Hispanic ethnicity."
"Our findings of higher neutralizing antibody levels in individuals of African descent post-rubella immunization are in line with, and may be related to, the higher immunoglobulin concentrations in blacks compared to whites (i.e., total IgG, IgG1, IgG2, IgM and IgA), which is largely attributed to genetic differences," the researchers note in their article.
"What we are seeing is that people from African American descent respond better," Dr. Poland told Reuters Health. "We have a group of Somali Americans here and they had more than twice the response than Caucasians, and non-Somali African Americans were in between these two groups. Hispanic Americans had the lowest response."
"We didn't find any gender differences, although we have found that to be true in all other vaccines being studied, where women always respond better than men for reasons we don't understand," Dr. Poland said.
Further studies are needed on the genetic factors, biological processes and pathways involved in forming and maintaining the humoral and cellular immune responses following vaccination in different racial/ethnic groups, the researchers say. "Such knowledge may be used to design and develop better vaccines for individuals and/or racial/ethnic groups through increasing vaccine efficacy and reducing vaccine adverse events."
Are we moving toward an era of tailored vaccines? Possibly, Dr. Poland said, "although I'm not saying we can go there yet. Depending on the subgroup to which you belong, we might tailor or individualize our approach. For example, this might mean maybe we give half the dose to Somalis and double the dose to Hispanics. Or, we make a more immunogenic vaccine for Hispanics or Caucasians."
The study was supported by the National Institute of Allergy and Infectious Diseases.
SOURCE: https://bit.ly/1mwLIkQ
Vaccine 2014.
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