Immune to flu after swine flu infection?

Immune to flu after swine flu infection: H1N1 virus supplies basis for the development of a universal vaccine

11.01.2011

People who have survived the swine flu virus infection are protected from a variety of common influenza viruses. US researchers report in the online edition of the journal „Journal of Experimental Medicine“, that infection with the H1N1 virus apparently leads to the formation of specific antibodies, the one „exceptional immune protection“ to numerous influenza strains.

Swine flu leads to the formation of special antibodies
Thus, the swine flu despite the deaths and the excitement about their recurrence, for some people also has a positive effect. In her body have formed after surviving infection with the H1N1 pathogen special antibodies that can fight a variety of different influenza viruses, the US researchers report Patrick Wilson from the University of Chicago. The formation of correspondingly diverse antibodies was favored by the special, different structure of the H1N1 virus. Because the swine flu pathogens are identical only in such parts with other influenza pathogens, which are essential for the functioning of the viruses, said Patrick Wilson and colleagues. Since all influenza viruses have these features, the antibodies formed can not only successfully control the swine flu pathogens but numerous different influenza virus strains, the researchers say. „While the flu is changing from year to year, some core elements have remained the same for almost a century“, stressed Wilson.

Antibodies protect against numerous influenza strains
To prevent the spread of the influenza virus in the body, the immune system develops specific antibodies that attach themselves to the viruses and turn them off. Which antibodies are formed in the course of a swine flu infection and to which influenza viruses they attach, the US researchers have now taken more closely by the samples of eight swine flu patients. In their study, scientists analyzed and reconstructed 86 different antibodies from the patients' blood, which they then tested in laboratory experiments on mice. The researchers were particularly interested in which influenza strains attached to the antibodies and how the flu infections in the animals were. Patrick Wilson and colleagues found that five antibodies fought all H1N1 strains in the past decade. Including the virus, which had caused the devastating Spanish flu in 1918 and the so-called bird flu virus, which could be extremely dangerous for humans under certain circumstances. Thus, individuals who have suffered from a swine flu infection are not only protected from future infections with H1N1 pathogens, but have human antibodies that are also effective against many other influenza strains, said the US researchers.

The Holy Grail of Vaccine Research
The results of the US scientists also open up new scope in the development of flu vaccines. Patrick Wilson was almost euphoric in light of the results, stressing that the antibodies he discovered for vaccine research „something like the Holy Grail“ are. Their study results show, „what to look out for when producing a flu vaccine so that it can be effective not just for a winter, but for many years to come“, Wilson explained. In fact, with the help of the results of the US researchers, it would finally be possible to make progress in finding an effective flu vaccine if it is possible to use the antibodies produced during the swine flu infection. A vaccine with such a large spectrum of activity would represent an important step in the fight against influenza, so the conclusion of the US researchers. Patrick Wilson rated the study results available to the newspaper „Daily Mail“ when „sensational“, because „it shows how to make a single vaccine that makes you immune to all types of influenza“.

New hope for an efficient flu vaccine
To date, the World Health Organizations (WHO) are recommending again each year which virus strains should contain the seasonal flu vaccine. To identify the appropriate influenza strains for this vaccine, WHO will monitor influenza cases worldwide and will designate appropriate antivirals annually. Strains that should be included in the vaccine. The vaccine serum generally contains components from three different strains of virus, with a H1N1 strain, an H3N2 strain and a strain of B-flu viruses being used for several years as these form the most common influenza pathogens. However, the US researchers hope that in the future, the annual vaccination procedure with the help of the swine flu pathogen can be significantly simplified. Scientists are working hard to develop a vaccine that could protect against all H1N1 strains and, ideally, all influenza pathogens.

Whether the current swine flu vaccine already unfold a broader effect than originally assumed and thus acts against other virus strains, the US researchers also want to investigate in a next step. Stephan Ludwig, an influenza expert at the University of Münster, emphasized that he considered this probable, but that a safe prediction was impossible, „because an infection is always something other than a vaccine.“ A new vaccine developed on the basis of the discovered antibody could be available within the next 10 years, according to the US researchers, and at best would need to be given only once in a lifetime. In the mice, the vaccine with the copied antibodies had already worked and the animals were even protected if they were vaccinated only 60 hours after the infection, emphasized Wilson and colleagues. (Fp)

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