Antibodies developed in patients who had the H1N1 pandemic flu strain that protect against a variety of flu strains.
The swine flu outbreak that swept across the globe claiming over 14,000 lives could provide scientists with a vital clue to creating a universal vaccine, a study claims. Researchers have found several patients infected with the 2009 H1N1 pandemic flu strain have developed antibodies that are protective against a variety of flu strains.
They believe that the unexpected turn of events could lead to the “holy grail” of a vaccine that protects against all strains of the disease.
It would also bring to an end the annual race to develop a vaccine for the latest strain of the disease and could even lead to a one-injection for life.
“The result is something like the holy grail for flu-vaccine research,” said study author Patrick Wilson, at the University of Chicago.
“It demonstrates how to make a single vaccine that could potentially provide immunity to all influenza.”
The scientists from Emory University School of Medicine and the University of Chicago studied nine patients who were affected by the 2009 strain with differing levels of severity from mild illness that waned after a few days to a severe case that required a two-month hospital stay including ventilator support.
Most were in their 20s or 30s and blood samples were taken.
The team identified white blood cells from the patients that made antibodies against flu virus, and then isolated the antibody genes from individual cells.
They used the genes to produce antibodies in cell culture – a total of 86 varieties – and then tested which flu strains they reacted against.
Five antibodies isolated by the team could bind all the seasonal H1N1 flu strains from the last decade, the devastating “Spanish flu” strain from 1918 and also a pathogenic H5N1 avian flu strain.
Seasonal flu shots contain three inactivated viral strains, each grown in chicken eggs.
Over the last decade, it was standard that one of the three is an H1N1 strain.
However, vaccination with any one H1N1 strain doesn’t usually result in protection against all of them – that’s why the 2009 strain could make so many people sick.
Some of the antibodies the team identified stick to the “stalk” region of part of the virus – a protein called haemagglutinin.
Because this part of the virus doesn’t change as much as other regions, scientists have proposed to make it the basis of a vaccine that could provide broader protection.
Dr Jens Wrammert, assistant professor of microbiology and immunology at Emory University, said: “Our data shows that infection with the 2009 pandemic influenza strain could induce broadly protective antibodies that are only rarely seen after seasonal flu infections or flu shots.
“These findings show that these types of antibodies can be induced in humans, if the immune system has the right stimulation, and suggest that a pan-influenza vaccine might be feasible.”
The antibodies isolated from a group of patients who were infected with the 2009 H1N1 strain could guide researchers in efforts to design a vaccine that gives people long-lasting protection against a wide spectrum of flu viruses.
The research team now plan to examine the immune responses of people who were vaccinated against the 2009 H1N1 strain but did not get ill.