Thursday, July 28, 2011. LONDON (Reuters).
Scientists have found a flu "super antibody" called FI6 that can fight all
types of influenza A viruses that cause disease in humans and animals and
say their discovery may be a turning point in the development of new flu
Researchers from Britain and Switzerland used a new method aimed at beating
"needle-in-a-haystack-type-odds" and managed to identify an antibody from a
human patient which neutralizes both main groups of influenza A viruses.
Although it is an early step, they said, it is an important one and in time
may pave the way for the development of a universal flu vaccine.
Vaccine makers currently have to change the formulations of their flu shots
every year to make sure they protect against the strains of the virus
circulating. This is a cumbersome process which takes time and money, so the
goal is come up with a universal flu vaccine that could protect people from
all flu strains for decades, or even for life.
Dozens of companies
make influenza vaccines, including Sanofi, GlaxoSmithKline, Novartis,
AstraZeneca and CSL.
"As we saw with the 2009 pandemic, a
comparatively mild strain of influenza can place a significant burden on
emergency services. Having a universal treatment which can be given in
emergency circumstances would be an invaluable asset," said John Skehel of
Britain's National Institute for Medical Research, who worked on the study
with colleagues from the privately-owned Swiss firm Humabs.
Lanzavecchia, Humabs' chief scientific officer and director of the Swiss
Institute for Research in Biomedicine, said high rates of seasonal flu and
the unpredictability of possible future pandemics underlined the need for
better treatments that target all flu viruses.
When someone is
infected with the flu virus, their antibodies target the virus'
hemagglutinin protein, the researchers explained in their study, which was
published on Thursday in the journal Science.
Because this protein
evolves so rapidly, there are currently 16 different subtypes of influenza
A, which form two main groups. Humans usually produce antibodies to a
specific subtype, and new vaccines are made each year to match these
To make progress toward a universal shot that could be used
every year, scientists need to identify the molecular signatures that prompt
the development of broadly neutralizing antibodies.
work has found antibodies that work in Group 1 influenza A viruses or
against most Group 2 viruses, but not against both.
developed a method using X-ray crystallography to test very large numbers of
human plasma cells, to increase their odds of finding an antibody even if it
was extremely rare.
When they identified FI6, they injected it into
mice and ferrets and found that it protected the animals against infection
by either a Group 1 or Group 2 influenza A virus.
"As the first and
only antibody which targets all known subtypes of the influenza A virus, FI6
represents an important new treatment option," Lanzavecchia said in a
Researchers in the United States said last year they were
having some success with another possible approach to developing a universal
flu shot, using a two-step system of a vaccine using DNA to "prime" the
immune system and then a traditional seasonal flu shot.
Science, online July 28, 2011.