Seniors generate fewer antibodies against influenza vaccine

With the arrival of autumn the northern hemisphere countries implement their vaccination campaigns against flu viruses. Some campaigns are intensified in winter and that, although open to everyone, are specifically targeted at risk groups. This applies, among others, pregnant women, the morbidly obese or people with cardiovascular or respiratory diseases and also, for people over 65 years. However, according to a study carried out by researchers at the University of California, the immune response to the vaccine for older people is different from that of the younger population, reason which is less effective.

The results provide further evidence on the reduced vaccination immune response of older people. Thus, the study provides a more complete picture of how the immune system responds to the vaccine, which can help in the development of vaccines that offer longer lasting immunity and better protection for all risk groups.

More monocytes, fewer antibodies

Influenza vaccine includes virus proteins which, once inoculated into the body, causes the immune system to generate antibodies. Thus, the vaccinated acquires protection – or immunity – against the virus. However, this protection is less in the case of the elderly.

Specifically, researchers evaluated the response to the vaccine in 212 people over five vaccination campaigns – from 2007 to 2012. And also they analyzed the data published in the first study conducted with 218 other subjects.

One week after administration of the vaccine, younger participants showed high levels of B lymphocytes, cells responsible for the production of immune system antibodies. However, people over -defined in this study as those with age or after 54 years they had high levels of B cells but monocytes, cells responsible for the inflammatory immune system response. And this difference between B lymphocytes and monocytes explains why the three weeks the vaccine-induced immune response may fail in older people.

The authors suggest, observed levels of B lymphocytes and monocytes prior to vaccination should be sufficient to predict the level of efficacy of the vaccine after four weeks of administration. The concept is that the inflammatory response can be harmful to the vaccine induction of antibody production. In order to increase the effectiveness of the vaccine possibly would reduce the inflammatory response in the elderly once they are vaccinated.