US scientists have identified a new strain of influenza in harbor seals that could potentially impact human and animal health.
The H3N8 flu has been associated with the deaths of harbor seals in New England last year.
Researchers say the virus may have evolved from a type that had been circulating in birds.
They say the discovery highlights the potential for pandemic flu to emerge from unexpected sources.
US scientists have identified a new strain of influenza in harbor seals that could potentially impact human and animal health
Researchers were puzzled by the mysterious deaths from pneumonia of 162 harbor seals around the coast of New England last year.
Autopsies on five of the marine mammals indicate that they died from a type of H3N8 influenza A virus that is closely related to a strain circulating in North American birds since 2002.
The scientists say this flu has evolved to live in mammals and has mutated to make it more transmissable and more likely to cause severe symptoms. The virus also has the ability to target a protein found in the human respiratory tract.
Dr. Anne Moscona of Weill Cornell Medical College in New York City edited the report and says that the new virus is a worry.
“There is a concern that we have a new mammalian-transmissable virus to which humans haven’t yet been exposed. It’s a combination we haven’t seen in disease before.”
While flu viruses have turned up in seals before, the researchers say this new virus may represent the first sighting of a new group with the potential to persist and move between species. The scientists had not considered that a bird flu infection could jump species to seals.
They argue that this highlights the fact that a pandemic influenza could emerge from a number of different routes.
“Flu could emerge from anywhere and our readiness has to be much better than we previously realized. We need to be very nimble in our ability to identify and understand the potential risks posed by new viruses from unexpected sources,” Dr. Anne Moscona said.
The report is published in the journal of the American Society for Microbiology.
US researchers say smokers could one day be immunized against nicotine so they gain no pleasure from the habit.
They have devised a vaccine that floods the body with an antibody to assault nicotine entering the body.
A study in mice, published in Science Translational Medicine, showed levels of the chemical in the brain were reduced by 85% after vaccination.
Years of research are still needed before it could be tested on people.
However, lead researcher Prof. Ronald Crystal is convinced there will be benefits.
“As far as we can see, the best way to treat chronic nicotine addiction from smoking is to have these Pacman-like antibodies on patrol, clearing the blood as needed before nicotine can have any biological effect.”
US researchers say smokers could one day be immunized against nicotine so they gain no pleasure from the habit
Other “smoking vaccines” have been developed that train the immune system to produce antibodies that bind to nicotine – it is the same method used to vaccinate against diseases. The challenge has been to produce enough antibodies to stop the drug entering the brain and delivering its pleasurable hit.
Scientists at Weill Cornell Medical College have used a completely different approach, a gene-therapy vaccine, which they say is more promising.
A genetically modified virus containing the instructions for making nicotine antibodies is used to infect the liver. This turns the organ into a factory producing the antibodies.
The research team compared the amount of nicotine in the brains of normal mice with those that had been immunized. After being injected with nicotine, the vaccinated mice had nicotine levels 85% lower.
It is not known if this could be repeated in humans or if this level of reduction would be enough to help people quit.
Prof. Ronald Crystal said that if such a vaccine could be developed then people “will know if they start smoking again, they will receive no pleasure from it due to the nicotine vaccine, and that can help them kick the habit”.
He added: “We are very hopeful that this kind of vaccine strategy can finally help the millions of smokers who have tried to stop, exhausting all the methods on the market today, but find their nicotine addiction to be strong enough to overcome these current approaches.”
There are also issues around the safety of gene therapy in humans that will need to be answered.
If such a vaccine was developed it could also raise ethical questions about vaccinating people, possibly in childhood, before they even started smoking.
