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COVID-19 vaccines may need to evolve to keep up with changing virus, experts say

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Nov. 9 (UPI) — Researchers working to develop a vaccine against COVID-19 must consider the inevitable mutation of the virus and monitor its evolution to ensure that inoculations continue to prevent infection, the authors of a commentary published Monday by PLOS Biology argue.

Even as new vaccines become available — perhaps as soon as later this year — researchers should use virus samples collected during testing to check for new strains that may not respond to the formulation, they said.

Multiple strains of the new coronavirus already have been identified, suggesting that the virus that originated in China is evolving and that new vaccines will need to keep up to provide immunity, according to the authors, both biologists at Penn State University.

The commentary was published on the same day that drugmaker Pfizer announced that its two-dose COVID-19 vaccine is 90% effective at preventing new infections, based on preliminary data from Phase 3 trials.

“I hope that the first licensed vaccine is safe, effective, and easy to produce and administer, but even if that is the case, [virus] evolution can undermine vaccine protection,” commentary co-author David A. Kennedy told UPI.

“Examples of resistance have been seen against many different types of vaccines … [so] I don’t think we can make blanket statements about which types of vaccine, or which types of diseases for that matter, will have problems with resistance,” said Kennedy, an assistant professor of biology.

Research suggests at least six different strains of the coronavirus that causes COVID-19 are circulating globally, although it appears to be evolving more slowly than it spreads, researchers said.

Roughly 200 vaccines against COVID-19 are being developed, with more than 40 already in clinical trials designed to assess safety and efficacy, according to the World Health Organization.

What Kennedy and his colleagues are proposing doesn’t call into question the trial process or delay it in any way, they said.

Instead, what they suggest is that researchers learn lessons from the antibiotic resistance crisis — in which infection-causing bacteria have become resistant to currently available antibiotics, leading to severe illness and death — and continue to track the evolution of the new coronavirus after vaccines come to market.

This would entail using samples collected during vaccine trials — including both nasal and throat swabs and blood — for new strains of the virus, Kennedy said.

For example, blood samples can be used to assess “the redundancy of immune protection generated by” vaccines by measuring the types and amounts of antibodies — proteins produced by the immune system to fight infection — that inoculated people develop against the virus.

“The data necessary to quantify the risk of vaccine resistance can be assessed concurrently with clinical trials,” Kennedy said.

“The question is, what do we do if we learn that an otherwise promising vaccine candidate is very likely to be undermined by pathogen evolution?” he asked.

One positive that can be taken from the need to develop a vaccine against COVID-19 is that the process, which has progressed at record pace, can be used to improve vaccines overall, according to Stephen S. Morse, an expert in emerging infectious diseases.

“Our knowledge of how vaccines work, and how to make them work better, still has many gaps,” Morse, a professor of epidemiology at Columbia University, who was not part of the PLOS Biology commentary, told UPI.

“This is a great opportunity to fill in some of the gaps [and] provide the opportunity for more precise assessments of the immune response to these vaccines, and help us learn how to design better ones,” which is essentially what the authors are proposing, he said.



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Moderna says data show COVID-19 vaccine almost 95% effective

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Nov. 16 (UPI) — The COVID-19 vaccine under development by U.S. biotech firm Moderna is 94.5% effective in preventing infection, according to interim data the company published Monday.

Moderna said early analysis from its late-stage “COVE” clinical trial for its mRNA-1273 vaccine candidate was based on nearly 100 COVID-19 cases.

“This is a pivotal moment in the development of our COVID-19 vaccine candidate,” Moderna CEO Stephane Bancel said in a statement. “Since early January, we have chased this virus with the intent to protect as many people around the world as possible. All along, we have known that each day matters.

“This positive interim analysis from our Phase 3 study has given us the first clinical validation that our vaccine can prevent COVID-19 disease, including severe disease.”

Moderna said its COVE trial has found no serious side effects from the mRNA-1273 vaccine.

Bancel said the company will apply for emergency use authorization from the Food and Drug Administration to distribute the vaccine once it finishes compiling safety data later this month.

“These are obviously very exciting results,” Dr. Anthony Fauci, the nation’s top infectious diseases expert, said Monday. “It’s just as good as it gets — 94.5% is truly outstanding.”

Moderna’s results are similar to those published last week by drugmaker Pfizer, which said its vaccine has shown to be about 90% effective.

Other vaccines are being tested in late-stage trials by Johnson & Johnson, AstraZeneca and Novavax.

Fauci said last week a vaccine could be available to the most at-risk populations before the end of the year.



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Experimental herpes vaccine shows promise in lab trials

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Scientists are reporting early success with an experimental herpes vaccine that uses a genetically modified version of the virus.

The gene edit prevents the virus from performing its normal evasive maneuver: hiding out in nervous system cells in order to elude the immune system.

So far, the vaccine has only been tested in lab animals. But scientists hope the genetic tweak will eventually allow the vaccine to succeed where past ones have failed.

The target is herpes simplex virus, or HSV, which in humans includes HSV-1 and HSV-2. Both can cause genital herpes, though HSV-1 is best known for triggering cold sores.

Globally, a half-billion people aged 15 to 49 have a genital herpes infection, according to the World Health Organization.

Those figures alone show there is a “huge need” for a vaccine, said Gary Pickard, one of the researchers on the new study.

But beyond that, once HSV invades the body, it’s there to stay, said Pickard, a professor of neuroscience at the University of Nebraska-Lincoln School of Veterinary Medicine and Biomedical Sciences.

To evade the immune system, the virus works its way into nerve cells and remains there in a dormant state. It can periodically become active again, traveling to the skin and causing sores and other symptoms.

In addition to those flare-ups, HSV infection can sometimes lead to complications. Pregnant women can, rarely, pass it to their newborns, who can become very sick or die, said Terri Warren, a registered nurse and medical advisor to the American Sexual Health Association.

Genital sores, and active HSV infection, also leave people more vulnerable to contracting HIV.

“In some places,” Warren said, “it accounts for many cases of HIV.”

Genital herpes also exacts a psychological toll, she explained, because it’s a lifelong infection that people can transmit to their partners, even when they are symptom-free.

That’s why researchers have been trying for years to create a preventive vaccine — with no success thus far.

As Pickard explained, one issue is that some candidate vaccines use only a subset of HSV components, or antigens, to try to generate an immune response. And that may not be enough: One vaccine with that design failed to prevent HSV-2 infection in a clinical trial involving thousands of young women.

Some other experimental vaccines have used a live, weakened form of HSV, but have run into similar issues.

“They’ve essentially made the virus so ‘sick’ that it can’t illicit a strong immune response,” Pickard said.

The new approach, recently described in the journal npj Vaccines, might circumvent those problems.

For the study, the researchers tested a vaccine made with a live, weakened form of HSV-1 that has a key genetic edit: It prevents the virus from advancing into the nervous system, while allowing it to replicate outside nerve tissue, to draw an immune response.

In lab experiments with guinea pigs, the tactic showed promise.

Of 12 animals given skin injections of the vaccine, only one developed sores after being exposed to HSV-2. In contrast, sores cropped up in 10 of 12 guinea pigs given no vaccine, and in five of 12 given the vaccine that failed in the earlier, human clinical trial.

In addition, the modified vaccine cut the viral shedding period by more than half, from 29 days to about 13. That’s important, Pickard said, because in humans it’s the viral shedding that can transmit the infection, even when there are no sores present.

“The findings on viral shedding are positive,” agreed Warren, who was not involved in the research.

She said a big question is whether a version of the vaccine that uses HSV-2 — rather than HSV-1 — can be shown effective in animals.

The researchers are working on that. Pickard said they are encouraged by the fact that the current vaccine showed “cross-protection” against HSV-2: If anything, they anticipate that an HSV-2 version will be more effective.

The road to an approved vaccine, however, is a long and very expensive one.

The hope is to have a vaccine ready for initial, phase I human testing within a few years, according to Pickard.

More information

The American Sexual Health Association has more on herpes.

Copyright 2020 HealthDay. All rights reserved.



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New procedure shows promise for pain relief in shoulder, hip arthritis

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Nov. 16 (UPI) — A method of “stunning” nerves reduces pain by at least 70% in people with moderate to severe arthritis in their hip and shoulder joints, a study presented Monday during the annual meeting of the Radiological Society of North America found.

In the method, called cooled radio-frequency ablation, needles are placed on the main sensory nerves around the shoulder and hip joints, the researchers said.

The nerves, which cause the body to feel pain, are then treated with a low-grade current known as radio frequency that “stuns” them, slowing the transmission of pain to the brain, they said.

The procedure could help the need for potentially addictive opioid-based pain relievers in people with moderate to severe arthritis pain, the researchers said.

“We’re just scratching the surface here,” study co-author Dr. Felix M. Gonzalez said in a statement.

“We would like to explore efficacy of the treatment on patients in other settings like trauma, amputations and especially in cancer patients with metastatic disease,” said Gonzalez, a professor of radiology at Emory University School of Medicine in Atlanta.

Historically, people with moderate to severe pain related to osteoarthritis have had limited treatment options — including the injection of corticosteroids into the affected joints — that tend to grow less effective as the arthritis progresses and worsens, according to Gonzalez and his colleagues.

“Usually, over time patients become less responsive to these injections,” he said.

Without pain relief, patients with this form of arthritis face the possibility of joint replacement surgery, but many aren’t candidates for these procedures due to other, underling health reasons, the researchers said.

For this study, 23 people — 12 with shoulder pain and 11 with hip pain — with osteoarthritis underwent treatment, the researchers said.

All 23 study participants had pain become unresponsive to anti-inflammatory and corticosteroid treatment, they said.

After receiving cooled radio-frequency ablation, the participants completed surveys to measure their function, range of motion and degree of pain prior to and at three months following the procedure.

No procedure-related complications occurred, and participants in the hip and shoulder groups reported significant reductions in pain with corresponding increases in joint function after the treatment, the researchers said.

Based on survey responses, participants with shoulder pain reported an 85% decrease in pain and a 74% increase in function, on average, Gonzalez said.

Those with hip pain reported a 70% reduction in pain and a 66% gain in function, he said.

“Until recently, there was no other alternative for the treatment of patients at the end of the arthritis pathway who do not qualify for surgery or are unwilling to undergo a surgical procedure,” Gonzalez said.

“This procedure is a last resort for patients who are unable to be physically active and may develop a narcotic addiction,” he said.



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