Research reveals protective properties of influenza vaccines

March 25, 2013

(Medical Xpress)—Collaborating scientists from Nationwide Children's Hospital, Baylor Institute for Immunology Research, and Mount Sinai School of Medicine have identified an important mechanism for stimulating protective immune responses following seasonal influenza vaccinations. The study was published in Science Translational Medicine, a journal of the American Association for the Advancement of Science (AAAS).

While vaccines protect 60 to 90 percent of healthy adults from "the flu," the mechanisms providing that protection are still not well understood.

The study led by Octavio Ramilo, MD, chief of Infectious Diseases and an investigator in the Center for Vaccines and Immunity at Nationwide Children's Hospital and professor of Pediatrics at The Ohio State University (OSU) College of Medicine, and Hideki Ueno, MD, PhD, an investigator at the Baylor Institute for Immunology Research at Baylor University, demonstrates how certain in the blood are stimulated to provide protective antibody responses with seasonal flu vaccines.

Antibodies are produced by specific or , which serve as an immune defense against foreign bodies such as the . Helper T , another type of white cell, are essential for the generation of B cells.

Blood samples before and after influenza vaccination from three groups of healthy study participants were analyzed for antibody responses. The groups included two sets of adults, one receiving flu vaccines during the 2009-2010 winter and the other receiving vaccination during the 2011-2012 winter. The third group included children receiving the during the 2010-2011 winter.

Analyses show that a temporary increase in a unique subset of helper T cells expressing the co-stimulator molecule ICOS adds to the immune response by helping B cells produce influenza-specific antibodies.

Results indicated that at day seven following the administration of a flu vaccine in all groups, stimulated T cells were evident, contributing to the development of the immune response.

The T cells positively correlated with increased antibodies against each flu virus strain examined, with the exception in the children's group against the swine-origin H1N1 virus.

"Given that seasonal influenza vaccines induce mainly through boosting the recall response of the immune system, this lack of correlation might reflect the lack of H1N1 specific immunity in some children," explains study co-author Emilio Flano, PhD, a principal investigator in the Center for Vaccines and Immunity at Nationwide Children's and an associate professor of Pediatrics at OSU College of Medicine.

"This is consistent with the fact that these children had not been vaccinated or naturally exposed to the H1N1 virus prior to being vaccinated during the 2010-2011 winter," said study co-author Santiago Lopez, MD, a postdoctoral research fellow in the Center for Vaccines and Immunity and a resident at Nationwide Children's.

Further experiments demonstrated that this unique subset of helper T cells can boost production of existing antibodies that fight flu by stimulating memory B cells, but do not help production of new antibodies by naïve B cells.

"We're gratified that our study provides evidence of one of the essential events associated with the immune response following seasonal ," says Dr. Ramilo. "Understanding these processes is a key step toward developing more effective vaccines."

Related Stories

Recommended for you

Experimental MERS vaccine shows promise in animal studies

July 28, 2015

A two-step regimen of experimental vaccines against Middle East respiratory syndrome (MERS) prompted immune responses in mice and rhesus macaques, report National Institutes of Health scientists who designed the vaccines. ...

Can social isolation fuel epidemics?

July 21, 2015

Conventional wisdom has it that the more people stay within their own social groups and avoid others, the less likely it is small disease outbreaks turn into full-blown epidemics. But the conventional wisdom is wrong, according ...

Lack of knowledge on animal disease leaves humans at risk

July 20, 2015

Researchers from the University of Sydney have painted the most detailed picture to date of major infectious diseases shared between wildlife and livestock, and found a huge gap in knowledge about diseases which could spread ...

IBD genetically similar in Europeans and non-Europeans

July 20, 2015

The first genetic study of inflammatory bowel disease (IBD) to include individuals from diverse populations has shown that the regions of the genome underlying the disease are consistent around the world. This study, conducted ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.