Possible stop for annual flu shot

Influenza: New strategy for influenza vaccine

08/27/2014

People who get vaccinated against the flu have to repeat that every year so far. This could possibly change in the future by a new serum. Initial tests were promising, according to US researchers.

Influenza vaccination has so far been repeated every year

Those people who decide to get a flu shot have to repeat this every year. This could possibly be avoided in the future. US researchers have presented a strategy whose key is a type of virus that is largely unknown to the human immune system. The body then forms a particularly large number of antibodies, which in turn could subsequently protect against various types of virus. This report the scientists in the „Proceedings of the National Academy of Sciences“.

Vaccines of the previous year no longer fit

The reason the flu vaccine needs to be renewed every year is because viruses often change their molecular shape. Even with minimal changes, the vaccines of the previous year no longer match the currently circulating viruses. Then they do not protect enough from the disease. Therefore, the vaccines are adapted each year to the type of virus currently circulating. After vaccination, the immune system produces antibodies to the virus. When the body gets back in contact with the virus later, the antibodies multiply rapidly and attack the virus.

Immune system forms antibodies

The immune system in the conventional flu vaccine is the most antibody to a protein on the surface of the virus (hemagglutinin), more specifically, against the variable region of this protein, which is constantly changing slightly. However, this protein also has a so-called stem region, which is far less variable. With a universal vaccine, the body would have to be made to produce antibodies against precisely those less variable regions of the hemagglutinin protein. The team led by Ali Ellebedy from the Emory Vaccine Center of the Emory University School of Medicine (Atlanta / US state of Georgia) initially observed that humans generally also have a few immune cells that produce antibodies against the stem region.

Formation of universal antibodies

However, after a conventional influenza vaccination, these immune cells are not stimulated to produce more antibodies. However, when the subjects were vaccinated with a virus type unknown to the immune system - in this case the avian flu virus, H5N1 - the body made more antibodies against the invariable stem region. As the researchers reported, the results outlined a potential vaccine strategy that could be used to immunize with H5N1, for example, to stimulate the generation of universal antibodies in humans.

Reservations against flu vaccination

In Germany, there are long-standing reservations about the flu vaccine. Last year, for example, a representative study conducted by the Federal Center for Health Education (BzgA) found that almost half of the respondents had never had themselves vaccinated and that there were doubts about the effectiveness and usefulness of this precautionary measure. The Standing Vaccination Commission (STIKO), however, recommends vaccination for persons from certain risk groups. These include people over the age of 60, those chronically ill with basic illnesses such as diabetes, asthma or cardiovascular diseases, medical staff and pregnant women from the second trimester of pregnancy. (Ad)