A vaccine breakthrough could finally bring COVID to its knees
With new COVID variants and sub-variants they are developing faster and faster, each one undermining the effectiveness of the leaders vaccinesis looking for a new type of vaccine – one that works equally well against current and future forms of the new coronavirus.
Now researchers at the National Institutes of Health in Maryland think they’ve found a new approach to vaccine design that could lead to a long-lasting shot. As a bonus, it might work too other corona virusesnot just the SARS-CoV-2 virus that causes COVID-19.
The NIH team reported their findings in a peer-reviewed study which appeared in the magazine Cell Host & Microbe earlier this month.
The key to the NIH’s potential vaccine design is a part of the virus called the “backbone helix.” It’s a coiled structure inside the spike protein, the part of the virus that helps it attach to and infect our cells.
Many current vaccines target the spike protein. But none of them specifically target helix spines. Still, there are good reasons to focus on that part of the pathogen. While many areas of the spike protein tend to change a lot as the virus mutates, the helix backbone no.
That gives scientists “hope that an antibody that targets this region will be more durable and more broadly effective,” Joshua Tan, lead scientist on the NIH team, told the Daily Beast.
Vaccines that target and “bind” to, say, the spike protein receptor-binding domain region may lose efficacy if the virus evolves within that region. The great thing about the spinal cord, from an immunological standpoint, is that it doesn’t mutate. At least it didn’t mutate morethree years after the COVID pandemic.
Thus, a vaccine that binds the backbone helix in SARS-CoV-2 should last a long time. And it should work against all the other coronaviruses that also involve the helix backbone—and there are dozens, including several like SARS-CoV-1 and MERS that have already made the jump from animal populations to cause outbreaks in humans.
To test their hypothesis, NIH researchers extracted antibodies from 19 recovered patients and tested them on samples from five different coronaviruses, including SARS-CoV-2, SARS-CoV-1 and MERS. Of the 55 different antibodies, most target parts of the virus that tend to mutate a lot. Only 11 targeted the spinal cord.
But the 11 who started after the spinal helix did better, on average, on the four coronaviruses. (A fifth virus, HCoV-NL63, rejected all antibodies.) The NIH team isolated the best antibody to the backbone helix, COV89-22, and also tested it in hamsters infected with the latest 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… highly neutralizing antibodies [coronaviruses] targeting the stem helix,” the researchers wrote.
Don’t break out the champagne yet. “Although these data are useful for vaccine design, we did not perform vaccination experiments in this study and therefore cannot draw any definitive conclusions regarding the efficacy of stem-helix-based vaccines,” the NIH team cautioned.
It’s one thing to test a few antibodies on hamsters. It’s another to develop, conduct trials, and get approval for an entirely new class of vaccines. “It’s really hard 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 the antibodies appear to be the spinal cord wide effective, it is unclear how they stack up against antibodies that are more specific. In other words, the spine-helix jab can work against a bunch of different but related viruses, but it works less well against any one virus than a jab specifically tailored for that virus. “Further experiments need to be done to assess whether they will be sufficiently protective in humans,” Tan said of the backbone helix antibodies.
There is a lot of work to be done before the spina bifida vaccine is available at the corner drug store. And there are many things that could disrupt that business. Additional studies could contradict the NIH team’s results. The new vaccine design may not work as well in humans as it does in hamsters.
The new jab could also be unsafe, impractical to manufacture, or too expensive for widespread distribution. Barton Haynes, an immunologist at Duke University, told The Daily Beast that he looked at backbone helix vaccine designs last year and concluded that they would be too expensive to justify the large investment. The main problem, he said, is that antibodies to the backbone helix are less potent and “difficult to induce” from their parent B-cells.
The more the pharmaceutical industry has to work to produce a vaccine and the more vaccine they have to pack into a single dose to compensate for the lower potency, the less cost effective the vaccine becomes for mass production.
Maybe a spinal tap is in our future. Or maybe not. In any case, it is encouraging that scientists are making progress towards it a more universal vaccine against the corona virus. 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 vaccine that is resistant to mutations.
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