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A lab-stage mRNA vaccine targeting ticks may offer protection against Lyme and other tick-borne diseases

The study found that ticks were unable to feed on guinea pigs vaccinated with an mRNA vaccine, preventing transmission of the pathogen that causes Lyme disease.

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As the rate of tick-borne diseases rises, vaccines that stop ticks in their tracks could be an essential preventive tool. rbkomar/Moment via Getty Images

The Research Brief is a short take about interesting academic work.

The big idea

A new laboratory-stage mRNA vaccine that teaches the immune system to recognize the saliva from tick bites could prevent these bugs from feeding on and transmitting tick-borne diseases to people, according to a recent study my colleagues and I conducted in the Fikrig Lab at the Yale School of Medicine.

Some animals repeatedly exposed to tick bites are eventually able to develop resistance to tick feeding, where the ticks either detach soon after biting or cause skin redness that alerts the host to remove them. Scientists have observed this tick immunity in several animals that don’t typically serve as hosts to ticks, including guinea pigs, rabbits and cows.

In laboratory settings, guinea pigs bitten 2-3 times by ticks are able to develop robust immunity against them. While there have not been any formal studies on tick immunity in humans, people who have been repeatedly exposed to ticks can get itchy skin after getting bitten, a symptom that may be associated with tick immunity.

Our lab was curious if we could induce tick immunity without tick bites. So we developed an mRNA vaccine called 19ISP that teaches cells to recognize 19 selected proteins present in the spit that Ixodes scapularis, also known as the deer or black-legged tick, leaves on the skin during a bite. Instead of targeting proteins on the invading pathogen – like the spikes on the outside of the coronavirus – our vaccine targets proteins naturally found in the tick’s saliva.

We found that guinea pigs vaccinated with 19ISP developed skin redness after they were bitten, indicating that their immune system was activated and recruited inflammatory cells to the site to fight off infection. Like other animals that developed tick immunity after repeated bites, the ticks were unable to feed on the guinea pigs and quickly detached. None of the vaccinated guinea pigs tested positive for Borrelia burgdorferi, the bacteria that causes Lyme disease. Conversely, almost half of the non-vaccinated guinea pigs tested positive for Borrelia infection.

Why it matters

Tick-borne diseases, including Lyme disease, are rising in North America and Europe, with almost 40,000 annual reported cases in the U.S. Ticks aren’t just a cause of trouble for wilderness hikers – they also pose a danger to farm workers and anyone outdoors. Beyond Lyme disease, ticks also transmit several other pathogens that can cause serious and potentially life-threatening conditions.

Tick perched on the the edge of a leaf.
Tick ranges have increased with climate change, putting more people and animals at risk for tick-borne diseases. Jaqueline Matias, CC BY-NC-ND

What’s unique about the 19ISP mRNA vaccine is that instead of directly targeting the pathogen that causes the disease like traditional vaccines, 19ISP was able to stimulate resistance to the carrier of the disease, ticks, and prevent them from transmitting the pathogen in the first place. Our study also suggests that this form of tick-based vaccination – teaching the body to rapidly recognize and react to being bitten by a tick – may be sufficient to prevent infection.

What still isn’t known

While guinea pigs were able to develop tick immunity, we’ve found that animals like mice do not. We plan to test this mRNA vaccine model in other animals, such as rabbits, to better understand how tick immunity varies in different tick hosts. We also plan to develop vaccines for other tick-borne pathogens and test for whether immunity extends to different tick species as well.

Our hope is that vector-based mRNA vaccines targeting the disease carrier can be applied to other vector-borne diseases. However, the feeding strategies of each disease vector is different – tick bites are not the same as mosquito bites, for instance. Because the way disease-carriers transmit pathogens may be different, vaccines may need to be modified for each vector.

What’s next

We plan on conducting studies on people who already have Lyme disease or who are repeatedly exposed to ticks to see if they have developed antibodies that recognize the proteins in 19ISP. This will further clarify how tick immunity works, and may eventually lead to clinical trials testing these vaccines in people.

[Climate change, AI, vaccines, black holes and much more. Get The Conversation best science and health coverage.]

Andaleeb Sajid currently for National Institutes of Health.

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Spread & Containment

TJ Maxx and Marshalls follow Costco and Target on upcoming closures

Many of these stores have information customers need to know.

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U.S. consumers have come to increasingly rely on the near ubiquity of convenience stores and big-box retailers. 

Many of us depend on these stores being open practically all day, every day, even during some of the biggest holidays. After all, Black Friday beckons retail stores to open just hours after a Thanksgiving Day dinner in hopes of attracting huge crowds of shoppers in search of early holiday sales. 

Related: Walmart announces more store closures for 2024

And it's largely true that before the covid pandemic most of our favorite stores were open all the time. Practically nothing — from inclement weather to bad news to holidays — could shut down a major operation like Walmart  (WMT)  or Target  (TGT)

Then the pandemic hit, and it turned everything we thought we knew about retail operations upside down. 

Everything from grocery stores to shopping malls shut down in an effort to contain potential spread. And when they finally reopened to the public, different stores took different precautionary measures. Some monitored how many shoppers were inside at once, while others implemented foot-traffic rules dictating where one could enter and exit an aisle. And almost every one of them mandated wearing masks at one point or another. 

Though these safety measures seem like a distant memory, one relic from the early 2020s remains firmly a part of our new American retail life. 

A woman in a face mask shopping in the HomeGoods kitchen aisle.

Jeff Greenberg/Getty Images

Store closures announced for spring 2024

Many retailers have learned to adapt after a volatile start to this third decade, and in many ways this requires serving customers better and treating employees better to retain a workforce. 

In some cases, the changes also reflect a change in shopping behavior, as more customers order online and leave more breathing room for brick-and-mortar operations. This also means more time for employees. 

Thanks to this, big retailers have recently changed how they operate, especially during holiday hours, with Walmart recently saying it would close during Thanksgiving to give employees more time to spend with loved ones.

"I am delighted to share that once again, we'll be closing our doors for Thanksgiving this year," Walmart U.S. CEO John Furner told associates in a video posted to Twitter in November. "Thanksgiving is such a special day during a very busy season. We want you to spend that day at home with family and loved ones." 

Other retailers have now followed suit, with Costco  (COST) , Aldi, and Target all saying they would close their doors for 24 hours on Easter Sunday, March 31. 

Now, the stores that operate under TJX Cos.  (TJX)  will also shut down during the holiday, including HomeGoods, TJ Maxx and Marshalls

Though it closed on Thanksgiving, Walmart says it will remain open for shoppers on Easter. 

Here's a list of stores that are closing for Easter 2024: 

  • Target
  • Costco
  • Aldi
  • TJ Maxx
  • Marshalls
  • HomeGoods
  • Publix
  • Macy's
  • Best Buy
  • Apple
  • ACE Hardware

Others are expected to remain open, including:

  • Walmart
  • Ikea
  • Petco
  • Home Depot

Most of the stores closing on Sunday will reopen for regular business hours on Monday. 

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International

Gates-backed PhIII study tuberculosis vaccine study gets underway

A large study of an experimental vaccine for the world’s biggest infectious disease has finally kicked off in South Africa.
The Bill & Melinda Gates…

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A large study of an experimental vaccine for the world’s biggest infectious disease has finally kicked off in South Africa.

The Bill & Melinda Gates Medical Research Institute (MRI) will test a tuberculosis vaccine’s ability to prevent latent infections from causing potentially deadly lung disease. Last summer the nonprofit said it would foot $400 million of the estimated $550 million cost of running the 20,000-person Phase III trial.

It’s a pivotal moment for a vaccine whose origins date back 25 years when scientists identified two proteins that triggered strong immunity to the bacterium that causes tuberculosis. A fusion of those proteins, paired with the tree bark-derived adjuvant that helps power GSK’s shingles shot, comprise the so-called M72 vaccine.

Thomas Scriba

After decades of failures in the field, the vaccine impressed scientists in 2018 when GSK found that it was 54% efficacious at preventing lung disease in a 3,600-person Phase IIb study.

But the Big Pharma decided that a full-blown trial was too expensive to conduct on its own. Gates MRI stepped in to license the vaccine in early 2020, right before the Covid pandemic shifted global vaccine priorities towards the coronavirus, further stalling the tuberculosis shot.

“There’s been frustration that it’s taken so long to get this trial up and running,” Thomas Scriba, deputy director of immunology for the South African Tuberculosis Vaccine Initiative, told Endpoints News last summer.

At last, the vaccine is getting a chance to prove itself in a bigger study. If successful, it could lead to the first new shot for tuberculosis in over a century.

Emilio Emini, CEO of the Gates MRI, told Endpoints that the initial results may come in roughly four to six years. “Hopefully this will galvanize a refocus on TB,” he said. “It’s been ignored for many, many years. We can’t ignore it anymore.”

A substantial impact

Even though an existing vaccine helps protect babies and children against severe tuberculosis, the bacterium responsible for the disease still causes roughly 10 million new cases and 500,000 deaths each year.

Emilio Emini

By vaccinating adolescents and adults who test positive for infections but don’t have symptoms of lung disease, the Gates MRI hopes the shot will help prevent mild infections from becoming severe ones, curtail transmission of the bug, which is predominantly driven by people with lung disease, and reduce deaths.

“The impact would be substantial,” Emini said. But he cautioned that the biology behind mild and severe diseases is still mysterious. “The reality is that no one really knows what keeps it under control.”

The study, which will take place at 60 sites across seven countries, will include some people who are not infected with tuberculosis to ensure that the vaccine is safe in that broader population.

“Having to pre-test everybody is not going to make the vaccine easy to deliver,” Emini said. If the vaccine is ultimately approved, it will likely be used in targeted communities with high tuberculosis, rather than across a whole country, he added. “In practice, you would immunize everybody in those populations.”

Emini described the Gates MRI’s rights to the vaccine as “close to a worldwide license.” GSK retained rights to commercialize the vaccine in certain countries but declined to specify which ones.

A spokesperson for GSK said that the company “has around 30 assets under development specifically for global health … none of which are expected to generate significant return on investment.”

“It is not sustainable or practical in the longer term for GSK to deliver all of these alone. So we continue to work on M72, but in partnership with others,” the spokesperson added.

If the shot works, Emini said that the Gates MRI will sublicense it to a manufacturer that will be responsible for making and marketing the vaccine. The details are still being worked out, he noted.

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Government

Choosing over the counter drugs for COVID 19? It’s complicated

COVID-19 illness may include symptoms such as a sore throat, fever, cough and fatigue. In January, the United States Centers for Disease Control and Prevention…

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COVID-19 illness may include symptoms such as a sore throat, fever, cough and fatigue. In January, the United States Centers for Disease Control and Prevention (CDC) issued its most recent guidelines for the use of over the counter (OTC) drugs for COVID-19. Specifically, its guidelines state that most people with COVID-19 have mild illness and can recover at home while treating symptoms with OTC medicines such as acetaminophen (Tylenol) or ibuprofen (Motrin, Advil). 

Credit: Florida Atlantic University

COVID-19 illness may include symptoms such as a sore throat, fever, cough and fatigue. In January, the United States Centers for Disease Control and Prevention (CDC) issued its most recent guidelines for the use of over the counter (OTC) drugs for COVID-19. Specifically, its guidelines state that most people with COVID-19 have mild illness and can recover at home while treating symptoms with OTC medicines such as acetaminophen (Tylenol) or ibuprofen (Motrin, Advil). 

Researchers from Florida Atlantic University’s Schmidt College of Medicine and academic colleagues say it’s more complicated. They suggest that selecting an OTC medication to alleviate mild symptoms of COVID-19 should be based on the entire benefit-to-risk profile of the patient. Moreover, they say clinical decisions should be made by the health care provider for each of his or her patients.

In a review, published in The American Journal of Medicine, researchers take a closer look at both the potential benefits and risks of acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen, as well as aspirin for the selection of OTC drugs to treat mild symptoms of COVID-19.

Traditional nonspecific NSAIDs such as the shorter acting ibuprofen and longer acting naproxen have been used to treat COVID-19. These widely used OTC drugs reversibly and non-specifically inhibit both cyclooxygenase enzyme isoforms. This results in systematic reduction in the synthesis of prostaglandins resulting in anti-inflammatory and fever-reducing effects. The researchers caution, however, that both ibuprofen and naproxen have similar but greater side effect profiles than aspirin, such as gastroenteritis and peptic ulcers.

Acetaminophen is one of the most frequently used OTC drugs in the U.S. and worldwide as a treatment for fever, allergic symptoms, headaches, myalgia, symptoms of the common cold, and most recently COVID-19. Acetaminophen was originally marketed as an alternative to aspirin for treatment of mild to moderate pain based on reduced mucosal gastrointestinal side effects. The authors caution that even at daily doses of 4,000 milligrams per day, generally accepted as safe for adults, acetaminophen can be toxic to the liver and may result in the onset of acute liver failure. In the U.S., acetaminophen is the leading reason for calls to Poison Control Centers with more than 100,000 cases per year. These circumstances account for more than 2,600 hospitalizations and 450 deaths in the U.S. due to acute liver failure. 

Aspirin, or acetylsalicylic acid, inhibits the production of prostaglandins, which are responsible for mediating pain, inflammation and fever. The authors say that the beneficial effects of aspirin include anti-platelet, analgesic, antipyretic or anti-fever and anti-inflammatory properties. Aspirin is rapidly absorbed when taken orally and has a half-life of around four hours, after which it is mostly metabolized by the kidneys.

The researchers note that the anti-inflammatory benefits of aspirin should provide symptomatic relief of fever and body aches in COVID-19. They underscore, however, that health providers should view these in the context of the increased risks of bleeding, principally gastrointestinal. Further, COVID-19 itself may already predispose individuals to bleeding as well as to clotting abnormalities.

“We believe that health care providers should make individual clinical judgments for each of his or her patients in the selection of OTC drugs to treat symptoms of COVID-19. This judgement should be based on the entire benefit to risk profile of the patient,” said Charles H. Hennekens, M.D., Dr.PH, senior author, first Sir Richard Doll Professor and senior academic advisor in FAU’s Schmidt College of Medicine. “It is our belief that the individual health care provider knows far more about each of his or her patients than anyone, including expert members of guideline committees.”

The authors conclude that when the totality of evidence is complete, health care providers can make the most rational individual clinical judgements for their patients and policymakers for the health of the general public.

The authors believe that, at present, the totality of evidence is incomplete and requires reliable evidence from large- scale randomized trials designed a priori to do so, which is necessary to develop rational guidelines. They also believe that any guidelines should provide only guidance to health care providers. Currently, these considerations pose new clinical challenges for health care providers in prescribing OTC drugs to treat COVID-19. 

“The astute and judicious individual clinical decision making of health care providers for each individual patient based on all these considerations has the potential to do far more good than harm. Finally, guidelines should provide guidance to individual health care providers,” said Hennekens.

Study co-authors are Gage Collamore, a second-year medical student; Mark J. DiCorcia, Ph.D., an associate professor and associate dean for educational affairs and admissions; Yash Nagpal, a second-year medical student; and Larry Fiedler, M.D., a board certified gastroenterologist and an affiliate associate professor, all within FAU’s Schmidt College of Medicine; Michael A. Garone, M.D., a board-certified gastroenterologist and clinical assistant professor at George Washington University Hospital; and David L. DeMets, Ph.D., emeritus Halperin Professor and founding chair of biostatistics and informatics; and Dennis G. Maki, M.D., the Ovid O. Meyer Professor of Medicine; both at the University of Wisconsin School of Medicine and Public Health.

Hennekens and Maki served for two years as lieutenant commanders in the U.S. Public Health Service as epidemic intelligence service (EIS) officers with the CDC. They served under Alexander D. Langmuir, M.D., who created the EIS and directed the epidemiology program at the CDC, as well as Donald A. Henderson, M.D., chief of the Virus Disease Surveillance Program at the CDC. Langmuir and Henderson made significant contributions to the eradication of polio and smallpox using widespread vaccinations and public health strategies of proven benefit and had extraordinary collaborations with local, state, federal and international health authorities.   

– FAU –

About the Charles E. Schmidt College of Medicine:

FAU’s Charles E. Schmidt College of Medicine is one of approximately 157 accredited medical schools in the U.S. The college was launched in 2010, when the Florida Board of Governors made a landmark decision authorizing FAU to award the M.D. degree. After receiving approval from the Florida legislature and the governor, it became the 134th allopathic medical school in North America. With more than 70 full and part-time faculty and more than 1,300 affiliate faculty, the college matriculates 64 medical students each year and has been nationally recognized for its innovative curriculum. To further FAU’s commitment to increase much needed medical residency positions in Palm Beach County and to ensure that the region will continue to have an adequate and well-trained physician workforce, the FAU Charles E. Schmidt College of Medicine Consortium for Graduate Medical Education (GME) was formed in fall 2011 with five leading hospitals in Palm Beach County. The Consortium currently has five Accreditation Council for Graduate Medical Education (ACGME) accredited residencies including internal medicine, surgery, emergency medicine, psychiatry, and neurology.

 

About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 30,000 undergraduate and graduate students across six campuses located along the southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, FAU embodies an innovative model where traditional achievement gaps vanish. FAU is designated a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report and a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. For more information, visit www.fau.edu.


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