With new variants and subvariants of COVID evolving faster and faster, each reducing the effectiveness of major vaccines, the hunt is on for a new type of vaccine, one that works equally well on current and future forms of the novel coronavirus. .
Now researchers at the National Institutes of Health in Maryland believe they’ve found a new approach to vaccine design that could lead them to a long-lasting hit. As a bonus, it might also work on other coronaviruses, not just the SARS-CoV-2 virus that causes COVID.
The NIH team reported their findings in a peer-reviewed study published in the journal Cell host and microbe earlier this month.
Key to the NIH’s potential vaccine design is a part of the virus called the “spinal helix.” It’s a coil-like structure inside the spike protein, the part of the virus that helps it latch onto and infect our cells.
Many current vaccines target the spike protein. But none of them specifically target the spinal helix. And yet, there are good reasons to focus on this part of the pathogen. While many regions of the spike protein tend to change a lot as the virus mutates, the spine helix doesn’t.
This gives scientists “hope that an antibody targeting this region will be more durable and broadly effective,” Joshua Tan, the NIH team’s lead scientist, told The Daily Beast.
Vaccines that target and “bind”, for example, the receptor-binding domain region of the spike protein could lose potency if the virus evolves in that region. The great thing about the spinal helix, from an immunological perspective, is that it doesn’t mutate. At least he didn’t mutate Againthree years after the start of the COVID pandemic.
So a vaccine that binds the spinal helix in SARS-CoV-2 should hold out for a long time. And it should also work on all the other coronaviruses that also include the spinal helix – and there are dozens, including several like SARS-CoV-1 and MERS that have already jumped animal populations. and caused epidemics in humans.
To test their hypothesis, the NIH researchers extracted antibodies from 19 recovering COVID patients and tested them on samples of five different coronaviruses, including SARS-CoV-2, SARS-CoV-1 and MERS. Of the 55 different antibodies, most have focused on parts of the virus that tend to mutate a lot. Only 11 targeted the spinal helix.
But those 11 that went after the spinal helix performed better, on average, on four of the coronaviruses. (A fifth virus, HCoV-NL63, ignored all antibodies.) The NIH team isolated the best spinal helix antibody, COV89-22, and also tested it on hamsters infected with the later subvariants. of the Omicron variant of COVID. “Hamsters treated with COV89-22 showed a reduced pathology score,” the team found.
The results are promising. “These findings identify a class of…antibodies that broadly neutralize [coronaviruses] by targeting the stem helix,” the researchers wrote.
Don’t sip the champagne yet. “While these data are useful for vaccine design, we did not perform vaccination experiments in this study and therefore cannot draw any firm conclusions regarding the efficacy of helix-based vaccines. stem,” the NIH team warned.
It’s one thing to test a few antibodies on hamsters. It is quite another to develop, test and gain approval for an entirely new class of vaccines. “It’s really difficult and most things that start out as good ideas fail for one reason or another,” James Lawler, an infectious disease expert at the University of Nebraska Medical Center, told The Daily Beast.
And while spine-helix antibodies seem to be widely effective, it is unclear how they compare to more specific antibodies. In other words, a spine-helix jab could work against a bunch of different but related viruses, but would work worse against any virus than a jab designed specifically for that virus. “Further experiments need to be done to assess whether they will be sufficiently protective in humans,” Tan said of spine-helix antibodies.
There’s a lot of work to be done before a spinal helix vaccine is available at the corner pharmacy. And there are many things that could derail this work. Additional studies may contradict the NIH team’s findings. The new vaccine design might not work as well in humans as it does in hamsters.
The new jab could also prove dangerous, impractical to produce, or too expensive for large-scale distribution. Barton Haynes, an immunologist at Duke University, told The Daily Beast that he reviewed spinal helix vaccine designs last year and concluded they would be too expensive to justify a major investment. The main problem, he said, is that anti-spinal helix antibodies are less potent and “difficult to induce” from their parental B cells.
The harder the pharmaceutical industry has to work to produce a vaccine, and the harder it has to package the vaccine in a single dose to compensate for lower potency, the less profitable a vaccine becomes for mass production.
Maybe a spine-helix jab is in our future. Or maybe not. Either way, it’s encouraging that scientists are gradually making progress towards a more universal coronavirus vaccine. One that could work for many years on a wide range of related viruses.
COVID for one is not going anywhere. And with each mutation, it risks becoming unrecognizable to current vaccines. What we need is a mutation-resistant vaccine.
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