Influenza annually reaps its victims. Scientists and doctors save lives, regularly rolling in the seasonal vaccine and deploying medicines to combat the virus and secondary infections. Nevertheless, the flu has killed tens of thousands of people and hospitalized hundreds of thousands. A particular challenge is to correctly predict which flu strains will have to be tame at certain times of the year. A team of scientists from the United States and China stated that it had developed a vaccine that can anticipate the peculiarity of seasonal influenza, increasing the ability of the immune system to combat many viral strains.
This week in Science published an article in which scientists from the University of California in Los Angeles has announced that it has created a “Goldilocks” flu vaccine — a vaccine that can induce a powerful immune response without infecting the animal. And unlike current influenza vaccines, the new version also fuels strong reactions of white blood cells that fight disease. This development is important because the response of T-cells, likely to give longer term protection than any vaccination, and protect against different influenza strains (because the T cells will look for a few different features of influenza virus and antibodies, as a rule, are focused on finding a specific strain). “It’s incredible,” says Kathleen Sullivan, chief allergist and immunologist, Children’s hospital of Philadelphia, was not involved in the work.
What is the approach of this team of scientists different from others? Usually the flu vaccine include a cocktail of several strains of killed virus. Injection of this compound into the body provokes the development of antibodies that can attack any intruder, resembling the flu, and thus prevent infection. But this standard method does not lead to the strong reaction of T cells because the virus is dead. In contrast, the new vaccine uses a live virus, so as to provoke a response of antibodies and T-cell immunity, at least in ferrets and mice. “Vaccines have a unique opportunity to cause a strong antibody response and induce T-cell response, which will be a protective net, so if the virus will break through the first line of defense, you will have T cells that will make sure that you don’t get sick much,” says Sullivan.
The researchers divided flu virus in a Petri dish and tested how different mutations in each segment react to the action of interferon, a protein released by the body during the attack of viruses, which helps to control the flu. Then the scientists were able to determine which mutations are likely to provoke protective action of interferons. Armed with this information, they developed a mutant strain of flu that was strong enough to play, but very susceptible to the ability of our body to control the virus — the perfect ingredients for the vaccine.
Vaccine performed well from ferrets and mice, which are often used for modeling influenza infection. If this approach will work for people, we might be able to eliminate the need for annual vaccinations against influenza. In the future, they also plan to test other variants of the virus and to select under them a universal vaccine.