The flu reaps its sacrifices every year. Scientists and medical professionals are saving lives by regularly rolling out seasonal vaccines and deploying drugs to fight the virus and its secondary infections. Nevertheless, tens of thousands of people die from the flu and hundreds of thousands are hospitalized. It is especially challenging to correctly predict which strains of influenza will have to be tamed at certain times of the year. A team of scientists from the United States and China said they have developed a vaccine that can anticipate seasonal flu by boosting the immune system's ability to fight many viral strains.
This week in Science, an article appeared in which scientists at the University of California, Los Angeles reported that they have created the "Goldilocks" flu vaccine - a vaccine that can induce a powerful immune response without infecting an animal. And unlike current flu vaccines, the new version also fuels a strong white blood cell response that fights disease. This development is important because the T cell response is likely to provide longer-term protection than any vaccine and will protect against different strains of influenza (since T cells will look for several different features of the influenza virus, and antibodies tend to focus on search for a specific strain). “It's incredible,” says Kathleen Sullivan, chief allergist and immunologist at Children's Hospital of Philadelphia, who was not involved.
How is the approach of this team of scientists different from others? Typically influenza vaccines include a cocktail of several strains of the killed virus. Injection of this mixture into the body triggers the development of antibodies that can attack any influenza-like intruder and thereby prevent infection. But this standard method does not produce a powerful T-cell response because the virus is dead. In contrast, the new vaccine uses a live virus, so it provokes both an antibody response and immune T cells, at least in ferrets and mice. “The vaccine has the unique ability to elicit both a strong antibody response and a T cell response that will become a defense network, so if the virus breaks through the first line of defense, you have T cells to make sure you don't get too sick. Sullivan says.
The researchers dismembered the influenza virus in a petri dish and tested how different mutations in each segment respond to the effects of interferon, a protein released by the body when attacked by viruses that helps control influenza. Then scientists were able to determine which mutations most likely provoked the action of protective interferons. Armed with this information, they developed a mutant influenza strain that was strong enough to reproduce but highly susceptible to our body's ability to control the virus - ideal ingredients for a vaccine.
The resulting vaccine has worked well in ferrets and mice, which are most often used to simulate influenza infection. If this approach works for humans too, we may be able to eliminate the annual need for flu shots. In the future, they also plan to test other variants of viruses and select universal vaccines for them.
Ilya Khel