Annual flu vaccines are essential but in five years a new answer may debut

A century ago, twenty years before the first flu vaccine debuted, the world experienced the largest disease outbreak in human history when “Spanish flu” swept the globe, killing 50 million people and infecting 500 million. Today the human population is seven times larger than it was in 1918, and experts say an outbreak of that magnitude now would overwhelm hospitals and health care providers.

To prevent a disaster of this sort from recurring, epidemiologists, physicians, and scientists work year-round to predict which influenza strain will hit next and develop a yearly flu shot to reduce the public’s risk of getting the flu. But while it’s our best defense against the flu, the shot isn’t perfect — and experts are still nervous that a pandemic will hit again.

“It will happen — I hope not in our lifetimes, but it will happen,” Jonah Sacha, Ph.D., a microbiologist, immunologist, and researcher at the Vaccine and Gene Therapy Institute at Oregon Health and Science University, tells Inverse. “If that would happen again now, with how connected the world is, we would be in bad shape.”

In response to the looming threat of another flu pandemic, teams of researchers, including Sacha, are pursuing a universal flu vaccine, supported by funding from The Gates Foundation. They want to create an influenza vaccine guarding against all versions of the virus, and even creating lifetime immunity, to replace the moderately effective yearly flu vaccine.

The best-case scenario: This forever flu shot could be here as early as five years from now.

"The flu suffers from a perception that it isn’t as bad as it really is.”

The flu, sometimes confused with the stomach ‘flu’ or other mild respiratory illnesses, isn’t always a passing nuisance. It tends to come on suddenly and causes debilitating symptoms including, but not limited to, fevers, chills, and fatigue. The flu typically passes after a miserable week or two but can also cause serious complications: pneumonia, bronchitis, asthma flare-ups, heart problems, ear infections, and in some cases, death.

“Actual influenza is very, very, very serious,” Sacha emphasizes. “There’s a reason why there’s so much lost time from work and why so many people die every year. It suffers from a perception that it’s not as bad as it really is.”

The CDC estimates that influenza results in between 140,000 – 960,000 hospitalizations and between 12,000 – 79,000 deaths annually.

Guessing Game

Currently, preventing the flu is one big guessing game: Researchers from the CDC, FDA, WHO, and NIH analyze global data on circulating influenza strains in humans and animal populations. Scientists map disease trends and identify the three or four strains most likely to hit during the upcoming flu season. This is a continuous and constant process.

Then, based on this process, they build vaccines. Scientists make particular viruses, kill them, then package the dead viruses in a vaccine, typically administered via a shot into the muscle tissue. The shot prompts the immune system to make antibodies to neutralize the dead viruses. Then, if the immune system is exposed to the real, live viruses later during flu season, it knows how to attack them.

Flu vaccines are not entirely effective. On a good year, the vaccine is about 60 percent effective and on a bad one, it prevents only 10 to 20 percent of flu cases.

“I think the influenza vaccine itself, because it changes every year and it doesn’t always work, really undermines the public’s trust in vaccines overall,” Sacha reflects. “I think having a universal influenza vaccine would be great because it would protect against influenza.”

“I think it would also drive home how important vaccines are.”

Chasing a ‘forever flu’ shot

Rethinking the current strategy, teams of researchers around the world, including Sacha’s lab, are pursuing influenza vaccines that provide better protection from various strains of influenza. The ultimate goal to have a world where people don’t head in for their yearly vaccines. Instead, this shot would provide lifelong immunity — something that’s evaded scientists for decades.

“The moonshot is a once-in-a-lifetime shot that gives you universal lifelong protection against influenza,” Sacha says. “If we hit that, it’s not even a home run. I don’t know what you’d call that… it’s like a solar system run. That’s absolutely stunning.”

"The moonshot is a once-in-a-lifetime shot that gives you universal lifelong protection against influenza.

His team is using a different virus, cytomegalovirus (CMV), as a “stealth vector” to teach the body to better defend against influenza. CMV is an extremely common virus, which rarely causes issues in healthy people and elicits T-cell production and storage in the lungs. T-cells are the soldiers of the immune system, which could be rapidly deployed upon flu infection.

If successful, Sacha’s vaccine would create a permanent reserve of immune system cells stored in the lungs, ready to attack influenza and stop it before it spreads. The idea may seem too good to be true, but Sacha says preclinical studies in HIV and tuberculosis (TB) using a similar approach have been promising. His influenza vaccine design is building off these insights.

Other scientists from Harvard University, University of Cambridge, the National of Allergy and Infectious Disease, and other places who have received funding from the Gates Foundation, are also trying to invent a new, better influenza vaccine using various tactics. The research for these teams is still preliminary, but could revolutionize the flu prevention process most people take for granted.

"The yearly flu shot isn’t perfect, but it is necessary.

In the meantime, Sacha says it is critical to keep getting your annual flu shot. Skipping the vaccine is like rolling the dice because we don’t know what the next few flu seasons are going to be like. Also, not getting the flu shot doesn’t just threaten your health — it could hurt others.

“If you’re someone that lives with small children or you’re someone who lives with the elderly, it’s incumbent upon you to get the annual flu shot every year because it’s not just for you,” Sacha emphasizes. “You’re protecting those people are most vulnerable in our population.”