This year's flu season has hit Californians hard, with 74 people under the age of 65 having died since October, compared with just 14 at this time last year. H3N2, the strain of virus currently circulating, is known for being particularly pernicious, but an ineffective flu vaccine is also to blame.
Every year the World Health Organization releases a recommendation to vaccine manufacturers, specifying which strains of the influenza virus they should use in their vaccine.
When everything goes as planned, as many as 60 percent of the people who get a flu shot will produce antibodies that will keep them from getting sick by attacking the virus as soon as it enters their bloodstream. But when the WHO misses the mark and the vaccine protects against the wrong strain of influenza, a public health crisis can ensue.
One of the solutions that researchers are working on? A "universal vaccine."
What does "universal" mean?
Exactly what it sounds like.
Whereas the current flu vaccine is only between 30-60 percent effective each season, a universal vaccine could be one shot, or a series of shots, that would protect you against all variants of the flu virus. That raises the possibility of never getting sick from the flu again.
Is it really a possibility?
"I don’t think it’s crazy to think that a universal vaccine is possible," said Dr. Charles Chiu, associate professor of infectious diseases at UC San Francisco. "There are several manufacturers that are working on potential candidate vaccines. And I think it is certainly something that we may be able to see in the next five to ten years."
How would a universal vaccine work?
The current flu vaccine is a collection of inactivated viruses that are injected into a person’s body. Their immune system responds by producing antibodies that then protect them against any live version of those viruses that they come in contact with..
However, there's a problem with this approach. The influenza virus is largely made up of RNA and eight different proteins, and some of those proteins mutate regularly, meaning that even if you were protected against a certain strain of flu, if the hemagglutinin protein in the virus mutates, your body can no longer easily defend itself against that virus, and you end up getting sick.
To address this, what some researchers have done over the past two decades is identify pieces of those eight proteins, called peptides, that remain consistent across different strains of the flu. Their goal is to get the body to build up defenses against those specific peptides, so that regardless of which flu strain enters the system, the body's T-cells and antibodies will be ready to fend them off.
Some companies posit that they can prep the body by injecting people with combinations of those peptides, although there are shortcomings to this method.
The theory is that if those never changing pieces of flu virus are targeted by the immune system, people can be protected against every strain of flu, regardless of its mutations.
What’s standing between researchers and success?
The problem is that the T-cells and antibodies are inclined to attack the parts of the flu virus that usually change. So, companies have to figure out a way to focus the immune system on the never-changing peptides, which is easier said than done.
How far is this from being reality?
Anywhere from three to ten years, according to several independent experts.
"Ultimately we’re going to work our way towards a universal flu vaccine," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
"It’s not going to happen in a home run tomorrow, but the technologies that we have, and the science as it goes in an iterative way, will get there," said Fauci, who's made finding a universal flu vaccine a primary focus of his organization.
There are major pharmaceutical companies, academic institutions and independent biotech firms working on developing a universal vaccine.
Vaccitech, which came out of Oxford University, just received $27 million from investment firms Seqoia Capital and Google Ventures, among others, in support of its universal vaccine research.
Another company, BiondVax, which hails from Israel, is entering phase 3 trials this coming fall. More than 9,000 adults over the age of 50 will be given either the company's experimental vaccine or a placebo over the course of two years.
Among many other factors, the company will have to see if the vaccine is effective, if it works against all variants of the flu and if there are any side effects.
Any company that has successful clinical trials, would then have to get FDA approval and figure out how to manufacture the vaccine on a large scale before taking it to market. That process could take years.
What does all of this mean for the future of the flu?
If someone successfully develops an effective universal flu vaccine, annual public health crisis could be averted, lives could be saved and the flu could become a worry of the past.
"I think that within our lifetimes that we would have the ability, hopefully, not to completely eradicate flu, which I think is going to be huge herculean task, but I think that we would have the ability to decrease the number of flu cases so that it becomes a very rare disease." said Dr. Chiu.