A Universal Vaccine for Flu
This spring, Dr. Slobodan Paessler was driving from Austin back towards Houston when he heard a feature on NPR. The subject was this year’s nationwide flu epidemic, something of a speciality for Paessler. But the advice a California physician gave on air didn’t ring true to him. In fact, it made him incredibly angry.
“Everything he said was wrong,” remembered Paessler, a viral pathologist at the University of Texas Medical Branch in Galveston. “He was telling people ‘you don't need to get vaccinated, because it doesn't work anyway this season.’ It was so misinformed, it was sad.”
Though Paessler tried to call the NPR station to voice his concerns and expertise, he couldn’t get through. But the incident served as a reminder of how misinformed even the medical community can be about the flu, and of how much good may come from one of Paessler’s projects — a universal flu vaccine.
Unlike current flu vaccines, which are only designed to protect against the handful of strains predicted to be the most active during a certain season, a universal flu vaccine could, in theory, protect against nearly every flu virus. The development of such a vaccine has been a stated goal of the Centers for Disease Control and Prevention and National Institute of Health for many years, and a number of variations are currently being researched.
“This is probably the top priority for the country. Even the NIH director and the CDC director and Congress representatives, everybody’s saying that we have to do something and have a better vaccine,” Paessler said. “And we’re certainly not the only ones working on it, but I think our technology is different from 95 percent of development in the field.”
Classic vaccines work very simply: Composed of dead or weakened viruses, they provoke the human body into producing targeted antibodies, which then remain in the body and protect against full-strength versions of the same virus. But Paessler’s flu vaccine differs from most others in that it drives the body to produce T cell responses to flu virus proteins, rather than to strain-specific antibodies. Because these T cells respond to the proteins in flu viruses that don’t change between strains, they’re able to successfully defend against a wide range of flu strains.
In partnership with Etubics, a biopharmaceutical company based out of Seattle, Paessler’s lab is moving closer to vaccine production. The cell systems that form the foundation of the vaccine are proven safe for people — they already have the FDA’s approval — and previous animal trials of the vaccine have proven effective. Etubics is currently preparing to take the vaccine to phase one clinical trials. “They already have the money, so it’s almost happening in real time,” Paessler said.
“Though we call it a ‘universal flu’ vaccine, it's not meant to be truly universal, but it is meant to cover many different viruses at the same time, in contrast to one target right now,” Paessler said. And because of the particular technology used to construct this universal flu vaccine, it is also more flexible and responsive than the vaccines now commonly administered across the country.
“It's very different from the classical flu yearly vaccine,” Paessler explained. “It has the advantage that it can be rapidly changed, because we can change the genetic information we're putting into our vector.”
That may sound like a simple thing, but the potential impacts of a broad spectrum flu vaccine that can be quickly adjusted to infection trends are huge.
“The current vaccines on the market, once they make a decision about what flu strain to target and go with the production of that vaccine, they can't really modify much until next year,” Paessler said. “With this type of a vaccine, you actually can. So if we make a H3 vaccine and that vaccine is not working well and we already know it in December, by the end of February this could start delivering a corrective vaccine. We can change the sequence as the virus is changing the situation.”
So while this universal flu vaccine may not be truly universal, it has the potential to answer many of Paessler’s most pressing concerns about flu vaccination in the U.S. — and to disprove once and for all the bad advice given by that California physician and many like him.
The problem, Paessler says, is that reports of low flu vaccine efficacy, whether true or not (and they often aren’t), convince people that vaccination isn’t worth it. Though this year’s flu vaccine was considerably more effective than first reported — 93 percent of H3N2 viruses were covered by the vaccine — many patients were told, and believed, that it wouldn’t keep them healthy. Once that trust is lost, it’s much more difficult to vaccinate those patients for the following flu season, or the next.
“Even if the efficacy is low, it’s still providing some coverage,” said Paessler. “The difference between receiving and not receiving the vaccine could be the difference between being hospitalized or not. That’s what’s getting lost in all this communication.”
One of the most tragic news to come out of the 2017-2018 flu season only reinforces his point. Of the 100 U.S. children who died of the flu this season, 87 weren’t vaccinated, according to a recent CDC report.
Those rates, Paessler said, are unacceptable — and doctors who reinforce the public’s doubt in vaccines are “co-responsible for some of these cases, because parents didn’t think vaccination was worth it and ‘even the doctor is saying so.’”
A universal vaccine, even if not truly universal, could help rebuild that lost trust.
“The benefit of a better vaccine for the patient would be very direct, particularly one that could respond and change as needed,” he said. “Over time you could even create more trust that you have it under control, so you might increase the total number of vaccinations due to improving the situation.”
And while flu certainly isn’t the only virus Paessler studies — he’s worked with Mad Cow, Ebola and just began a large project studying Lassa hemorrhagic fever in Nigeria — he says the universal flu project “is probably at the top” of his list of favorites.
“Flu is an interesting field in terms of research, vaccine production, public health, politics,” he says. “It’s a very unique mixture.” It’s also a way to tangibly improve public health.
“This is a problem I think we can solve,” Paessler said. “Then we’ll move on to the next issue.”