The first resistance to a new flu vaccine developed and produced by the world’s biggest drugmaker has been documented in pigs in Germany, the scientists working on the vaccine said Thursday.
Chad Verlander, lead scientist and director of the vaccine wing at Hamburg University of Applied Sciences, told reporters at a press conference that different types of human genetic material in pigs were becoming resistant to a tributyltin-C and other components of the experimental vaccine produced by GlaxoSmithKline.
The pigs began expressing flu symptoms in August, the research group said, and increasingly resistant to the vaccine.
Four strains of H3N2, including two new “highly active” strains, were developed and produced by the company in partnership with the European Research Group on influenza and in collaboration with HMG-CoV and HGSchold AG. This is the first new strain of the flu to be tested on humans in more than 15 years.
The experimental vaccine seems to work against two strains already circulating in humans, and is being given to people in an effort to control the flu pandemic. Studies of the vaccine in adults between ages 18 and 64 in Poland are underway.
If trials in humans are successful, Verlander said, the company may decide to give the vaccine to other countries in Europe and Africa as well.
The much anticipated experiment has produced a wildly diverse array of reactions, with H3N2 swine flu seriously damaging almost 60 percent of the animals studied, according to the research. Other studies found mild flu-like symptoms in between 55 percent and 79 percent of animals.
There is no approved vaccine in the U.S. to protect against the new H3N2 strains.
Drugmakers have been able to produce vaccines to combat the influenza virus, but they have faced increasing difficulty in doing so as the virus is becoming increasingly “resistant” to vaccines, Verlander said.
Carried by swine or birds, influenza can be carried in the air or shipped in water. Vectors have also become increasingly resilient to simple natural defenses developed by people, which are now cause more deaths than the virus itself.
“The combination of determined genetic evolution of the influenza viruses and successful design of new strategies, we have entered an era of ‘secreting strain strains by a long needle’, and that is driving the evolution of the influenza virus from a light spectrum to a dark range,” Verlander said.
HMG-CoV is a consortium of German laboratories responsible for producing vaccines to combat influenza.
Flu vaccine production has seen increasing difficulty in recent years, as scientists have been unable to produce much reliable vaccine against the H1N1 pandemic strain in 2009-2010.
According to Verlander, the German scientists are also working on creating another type of vaccine, which would be less dangerous for human healthcare workers in disease-stricken areas.
“So far there has been no mortality caused by respiratory illness among vaccinated farm animals,” Verlander said.
The scientists say there is no likelihood that humans will get sick from this particular strain of flu because as well as the swine flu strain, three other different types of influenza are circulating. However, they warn, people with immunity to the swine flu may develop a resistance to the version of influenza that is circulating.