Patients who have recovered from the H1N1 “swine flu” pandemic attack of last 2009 have developed atypical antibodies that might protect them from a variety of flu strains, the US researchers informed on Monday.

Specialists were stunned to discover that the immune response of the patients to a new flu could lead the way to a universal vaccine against several kinds of strains that have been present for decades, according to a study written in the Journal of Experimental Medicine.

US researchers examined nine patients who had been infected with the flu last year. They discovered antibodies that when tried on mice could shield them from a deadly dose of at least three various flu strains, as well as the bird flu.

Study author Patrick Wilson informed that the study showed how to create a single vaccine that could possibly offer immunity to all influenza. Patrick Wilson is the assistant professor of medicine at the University of Chicago.

It was a shock for them that a very different influenza strain, instead of the most common strains, could potentially give them a vaccine that is widely applicable to all sorts of influenza.

The researchers took blood samples from the patients around 10 days after they manifested symptoms of flu. Some had mild flu while others had severe form that required admission in the hospital.

The researchers isolated the antibodies that they had found in the patients blood. The study said that five of these antibodies could protect against all the seasonal H1N1 flu strains from the last decade, the ‘Spanish flu’ strain from 1918 and the pathogenic H5N1 avian flu.

Among the antibodies, only one showed protection against the 2009 H1N1 strain when tested on mice. The said antibody was taken from the patient who had the most severe H1N1 infection.

The virus infected millions of people and hospitalized thousands in United States. It was first detected year 2009 in United States and Mexico. Swine flu was different because it was more dangerous for pregnant women and young people than other strains of flu which are more lethal in the older generation.