Posted on by Lawrence Tabak, D.D.S., Ph.D.
The COVID-19 pandemic continues to present considerable public health challenges in the United States and around the globe. One of the most puzzling is why many people who get over an initial and often relatively mild COVID illness later develop new and potentially debilitating symptoms. These symptoms run the gamut including fatigue, shortness of breath, brain fog, anxiety, and gastrointestinal trouble.
People understandably want answers to help them manage this complex condition referred to as Long COVID syndrome. But because Long COVID is so variable from person to person, it’s extremely difficult to work backwards and determine what these people had in common that might have made them susceptible to Long COVID. The variability also makes it difficult to identify all those who have Long COVID, whether they realize it or not. But a recent study, published in the journal Lancet Digital Health, shows that a well-trained computer and its artificial intelligence can help.
Researchers found that computers, after scanning thousands of electronic health records (EHRs) from people with Long COVID, could reliably make the call. The results, though still preliminary and in need of further validation, point the way to developing a fast, easy-to-use computer algorithm to help determine whether a person with a positive COVID test is likely to battle Long COVID.
In this groundbreaking study, NIH-supported researchers led by Emily Pfaff, University of North Carolina, Chapel Hill, and Melissa Haendel, the University of Colorado Anschutz Medical Campus, Aurora, relied on machine learning. In machine learning, a computer sifts through vast amounts of data to look for patterns. One reason machine learning is so powerful is that it doesn’t require humans to tell the computer which features it should look for. As such, machine learning can pick up on subtle patterns that people would otherwise miss.
In this case, Pfaff, Haendel, and team decided to “train” their computer on EHRs from people who had reported a COVID-19 infection. (The records are de-identified to protect patient privacy.) The researchers found just what they needed in the National COVID Cohort Collaborative (N3C), a national, publicly available data resource sponsored by NIH’s National Center for Advancing Translational Sciences. It is part of NIH’s Researching COVID to Enhance Recovery (RECOVER) initiative, which aims to improve understanding of Long COVID.
The researchers defined a group of more than 1.5 million adults in N3C who either had been diagnosed with COVID-19 or had a record of a positive COVID-19 test at least 90 days prior. Next, they examined common features, including any doctor visits, diagnoses, or medications, from the group’s roughly 100,000 adults.
They fed that EHR data into a computer, along with health information from almost 600 patients who’d been seen at a Long COVID clinic. They developed three machine learning models: one to identify potential long COVID patients across the whole dataset and two others that focused separately on people who had or hadn’t been hospitalized.
All three models proved effective for identifying people with potential Long-COVID. Each of the models had an 85 percent or better discrimination threshold, indicating they are highly accurate. That’s important because, once researchers can identify those with Long COVID in a large database of people such as N3C, they can begin to ask and answer many critical questions about any differences in an individual’s risk factors or treatment that might explain why some get Long COVID and others don’t.
This new study is also an excellent example of N3C’s goal to assemble data from EHRs that enable researchers around the world to get rapid answers and seek effective interventions for COVID-19, including its long-term health effects. It’s also made important progress toward the urgent goal of the RECOVER initiative to identify people with or at risk for Long COVID who may be eligible to participate in clinical trials of promising new treatment approaches.
Long COVID remains a puzzling public health challenge. Another recent NIH study published in the journal Annals of Internal Medicine set out to identify people with symptoms of Long COVID, most of whom had recovered from mild-to-moderate COVID-19 . More than half had signs of Long COVID. But, despite extensive testing, the NIH researchers were unable to pinpoint any underlying cause of the Long COVID symptoms in most cases.
So if you’d like to help researchers solve this puzzle, RECOVER is now enrolling adults and kids—including those who have and have not had COVID—at more than 80 study sites around the country.
 Identifying who has long COVID in the USA: a machine learning approach using N3C data. Pfaff ER, Girvin AT, Bennett TD, Bhatia A, Brooks IM, Deer RR, Dekermanjian JP, Jolley SE, Kahn MG, Kostka K, McMurry JA, Moffitt R, Walden A, Chute CG, Haendel MA; N3C Consortium. Lancet Digit Health. 2022 May 16:S2589-7500(22)00048-6.
 A longitudinal study of COVID-19 sequelae and immunity: baseline findings. Sneller MC, Liang CJ, Marques AR, Chung JY, Shanbhag SM, Fontana JR, Raza H, Okeke O, Dewar RL, Higgins BP, Tolstenko K, Kwan RW, Gittens KR, Seamon CA, McCormack G, Shaw JS, Okpali GM, Law M, Trihemasava K, Kennedy BD, Shi V, Justement JS, Buckner CM, Blazkova J, Moir S, Chun TW, Lane HC. Ann Intern Med. 2022 May 24:M21-4905.
COVID-19 Research (NIH)
National COVID Cohort Collaborative (N3C) (National Center for Advancing Translational Sciences/NIH)
Emily Pfaff (University of North Carolina, Chapel Hill)
Melissa Haendel (University of Colorado, Aurora)
NIH Support: National Center for Advancing Translational Sciences; National Institute of General Medical Sciences; National Institute of Allergy and Infectious Diseases
Posted on by Lawrence Tabak, D.D.S., Ph.D.
While great progress has been made in controlling the COVID-19 pandemic, America’s opioid crisis continues to evolve in unexpected ways. The opioid crisis, which worsened during the pandemic and now involves the scourge of fentanyl, claims more than 70,000 lives each year in the United States . But throughout the pandemic, NIH has continued its research efforts to help people with a substance use disorder find the help that they so need. These efforts include helping to find relief for the millions of Americans who live with severe and chronic pain.
Recently, I traveled to Atlanta for the Rx and Illicit Drug Summit 2022. While there, I moderated an evening fireside chat with two of NIH’s leaders in combating the opioid crisis: Nora Volkow, director of the National Institute on Drug Abuse (NIDA); and Rebecca Baker, director of Helping to End Addiction Long-term® (HEAL) initiative. What follows is an edited, condensed transcript of our conversation.
Tabak: Let’s start with Nora. When did the opioid crisis begin, and how has it changed over the years
Volkow: It started just before the year 2000 with the over-prescription of opioid medications. People were becoming addicted to them, many from diverted product. By 2010, CDC developed guidelines that decreased the over-prescription. But then, we saw a surge in heroin use. That turned the opioid crisis into two problems: prescription opioids and heroin.
In 2016, we encountered the worst scourge yet. It is fentanyl, an opioid that’s 50 times more potent than heroin. Fentanyl is easily manufactured, and it’s easier than other opioids to hide and transport across the border. That makes this drug very profitable.
What we have seen during the pandemic is the expansion of fentanyl use in the United States. Initially, fentanyl made its way to the Northeast; now it’s everywhere. Initially, it was used to contaminate heroin; now it’s used to contaminate cocaine, methamphetamine, and, most recently, illicit prescription drugs, such as benzodiazepines and stimulants. With fentanyl contaminating all these drugs, we’re also seeing a steep rise in mortality from cocaine and methamphetamine use in African Americans, American Indians, and Alaska natives.
Tabak: What about teens? A recent study in the journal JAMA reported for the first time in a decade that overdose deaths among U.S. teens rose dramatically in 2020 and kept rising through 2021 . Is fentanyl behind this alarming increase?
Volkow: Yes, and it has us very concerned. The increase also surprised us. Over the past decade, we have seen a consistent decrease in adolescent drug use. In fact, there are some drugs that have the lowest usage rates that we’ve ever recorded. To observe this more than doubling of overdose deaths from fentanyl before the COVID pandemic was a major surprise.
Adolescents don’t typically use heroin, nor do they seek out fentanyl. Our fear is adolescents are misusing illicit prescriptions contaminated with fentanyl. Because an estimated 30-40 percent of those tainted pills contain levels of fentanyl that can kill you, it becomes a game of Russian roulette. This dangerous game is being played by adolescents who may just be experimenting with illicit pills.
Tabak: For people with substance use disorders, there are new ways to get help. In fact, one of the very few positive outcomes of the pandemic is the emergence of telehealth. If we can learn to navigate the various regulatory issues, do you see a place for telehealth going forward?
Volkow: When you have a crisis like this one, there’s a real need to accelerate interventions and innovation like telehealth. It certainly existed before the pandemic, and we knew that telehealth was beneficial for the treatment of substance use disorders. But it was very difficult to get reimbursement, making access extremely limited.
When COVID overwhelmed emergency departments, people with substance use disorders could no longer get help there. Other interventions were needed, and telehealth helped fill the void. It also had the advantage of reaching rural populations in states such as Kentucky, West Virginia, Ohio, where easy access to treatment or unique interventions can be challenging. In many prisons and jails, administrators worried about bringing web-based technologies into their facilities. So, in partnership with the Justice Department, we have created networks that now will enable the entry of telehealth into jails and prisons.
Tabak: Rebecca, it’s been four years since the HEAL initiative was announced at this very summit in 2018. How is the initiative addressing this ever-evolving crisis?
Baker: We’ve launched over 600 research projects across the country at institutions, hospitals, and research centers in a broad range of scientific areas. We’re working to come up with new treatment options for pain and addiction. There’s exciting research underway to address the craving and sleep disruption caused by opioid withdrawal. This research has led to over 20 investigational new drug applications to the FDA. Some are for repurposed drugs, compounds that have already been shown to be safe and effective for treating other health conditions that may also have value for treating addiction. Some are completely novel. We have also initiated the first testing of an opioid vaccine, for oxycodone, to prevent relapse and overdose in high-risk individuals.
Tabak: What about clinical research?
Baker: We’re testing multiple different treatments for both pain and addiction. Not everyone with pain is the same, and not every treatment is going to work the same for everyone. We’re conducting clinical trials in real-world settings to find out what works best for patients. We’re also working to implement lifesaving, evidence-based interventions into places where people seek help, including faith, community, and criminal justice settings.
Tabak: The pandemic highlighted inequities in our health-care system. These inequities afflict individuals and populations who are struggling with addiction and overdose. Nora, what needs to be done to address the social determinants of racial disparities?
Volkow: This is an extraordinarily important question. As you noted, certain racial and ethnic groups had disproportionately higher mortality rates from COVID. We have seen the same with overdose deaths. For example, we know that the most important intervention for preventing overdoses is to initiate medications such as methadone, buprenorphine or vivitrol. But Black Americans are initiated on these medications at least five years later than white Americans. Similarly, Black Americans also are less likely to receive the overdose-reversal medication naloxone.
That’s not right. We must ask what are the core causes of limited access to high-quality health care? Low income is a major contributing factor. Helping people get an education is one of the most important factors to address it. Another factor is distrust of the medical system. When racial and ethnic discrimination is compounded by discrimination because a person has a substance use disorder, you can see why it becomes very difficult for some to seek help. As a society, we certainly need to address racial discrimination. But we also need to address discrimination against substance use disorders in people of all races who are vulnerable.
Baker: Our research is tackling these barriers head on with a direct focus on stigma. As Nora alluded to, oftentimes providers may not offer lifesaving medication to some patients, and we’ve developed and are testing research training to help providers recognize and address their own biases and behaviors in caring for different populations.
We have supported research on the drivers of equity. A big part of this is engaging with people with lived experience and making sure that the interventions being designed are feasible in the real world. Not everyone has access to health insurance, transportation, childcare—the support that they may need to sustain treatment and recovery. In short, our research is seeking ways to enhance linkage to treatment.
Nora mentioned the importance of telehealth in improving equity. That’s another research focus, as well as developing tailored, culturally appropriate interventions for addressing pain and addiction. When you have this trust issue, you can’t always go in with a prescription or a recommendation from a physician. So in American and Alaskan native communities, we’re integrating evidence-based prevention approaches with traditional practices like wellness gatherings, cooking together, use of sage and spirituality, along with community support, and seeing if that encourages and increases the uptake of these prevention approaches in communities that need it so much.
Tabak: The most heartbreaking impact of the opioid crisis has been the infants born dependent on opioids. Rebecca, what’s being done to help the very youngest victims of the opioid crisis born with neonatal opioid withdrawal syndrome, or NOWS?
Baker: Thanks for asking about the infants. Babies with NOWS undergo withdrawal at birth and cry inconsolably, often with extreme stomach upset and sometimes even with seizures. Our research found that hospitals across the country vary greatly in how they treat these babies. Our program, ACT NOW, or Advancing Clinical Trials in Neonatal Opioid Withdrawal, aims to provide concrete guidance for nurses in the NICU treating these infants. One of the studies that we call Eat, Sleep, Console focuses on the abilities of the baby. Our researchers are testing if the ability to eat, sleep, or be consoled increases bonding with the mother and if it reduces time in the hospital, as well as other long-term health outcomes.
In addition to that NOWS program, we’ve also launched the HEALthy Brain and Child Development Study, or HBCD, that seeks to understand the long-term consequences of opioid exposure together with all the other environmental and other factors the baby experiences as they grow up. The hope is that together these studies will inform future prevention and treatment efforts for both mental health and also substance use and addiction.
Tabak: As the surge in heroin use and appearance of fentanyl has taught us, the opioid crisis has ever-changing dynamics. It tells us that we need better prevention strategies. Rebecca, could you share what HEAL is doing about prevention?
Baker: Prevention has always been a core component of the HEAL Initiative in a number of ways. The first is by preventing unnecessary opioid exposures through enhanced and evidence-based pain management. HEAL is supporting research on new small molecules, new devices, new biologic therapeutics that could treat pain and distinct pain conditions without opioids. And we’re also researching and providing guidance for clinicians on strategies for managing pain without medication, including acupuncture and physical therapy. They can often be just as effective and more sustainable.
HEAL is also working to address risky opioid use outside of pain management, especially in high-risk groups. That includes teens and young adults who may be experimenting, people lacking stable housing, patients who are on high-dose opioids for pain management, or they maybe have gone off high-dose opioids but still have them in their possession.
Finally, to prevent overdose we have to give naloxone to the people who need it. The HEALing Communities Study has taken some really innovative approaches to providing naloxone in libraries, on the beach, and places where overdoses are actually happening, not just in medical settings. And I think that will be, in our fight against the overdose crisis, a key tool.
Volkow: Larry, I’d like to add a few words on prevention. There are evidence-based interventions that have been shown to be quite effective for preventing substance use among teenagers and young adults. And yet, they are not implemented. We have evidence-based interventions that work for prevention. We have evidence-based interventions that work for treatment. But we don’t provide the resources for their implementation, nor do we train the personnel that can carry it over.
Science can give us tools, but if we do not partner at the next level for their implementation, those tools do not have the impact they should have. That’s why I always bring up the importance of policy in the implementation phase.
Tabak: Rebecca, the opioid crisis got started with a lack of good options for treating pain. Could you share with us how HEAL’s research efforts are addressing the needs of millions of Americans who experience both chronic pain and opioid use disorder?
Baker: It’s so important to remember people with pain. We can’t let our efforts to combat the opioid crisis make us lose sight of the needs of the millions of Americans with pain. One hundred million Americans experience pain; half of them have severe pain, daily pain, and 20 million have such severe pain that they can’t do things that are important to them in their life, family, job, other activities that bring their life meaning.
HEAL recognizes that these individuals need better options. New non-addictive pain treatments. But as you say, there is a special need for people with a substance use disorder who also have pain. They desperately need new and better options. And so we recently, through the HEAL Initiative, launched a new trials network that couples medication-based treatment for opioid use disorders, so that’s methadone or buprenorphine, with new pain-management strategies such as psychotherapy or yoga in the opioid use disorder treatment setting so that you’re not sending them around to lots of different places. And our hope is that this integrated approach will address some of the fragmented healthcare challenges that often results in poor care for these patients.
My last point would be that some patients need opioids to function. We can’t forget as we make sure that we are limiting risky opioid use that we don’t take away necessary opioids for these patients, and so our future research will incorporate ways of making sure that they receive needed treatment while also preventing them from the risks of opioid use disorder.
Tabak: Rebecca, let me ask you one more question. What do you want the folks here to remember about HEAL?
Baker: HEAL stands for Helping to End Addiction Long-term, and nobody knows more than the people in this room how challenging and important that really is. We’ve heard a little bit about the great promise of our research and some of the advances that are coming through our research pipeline, new treatments, new guidance for clinicians and caregivers. I want everyone to know that we want to work with you. By working together, I’m confident that we will tailor these new advances to meet the individual needs of the patients and populations that we serve.
Tabak: Nora, what would you like to add?
Volkow: This afternoon, I met with two parents who told me the story of how they lost their daughter to an overdose. They showed me pictures of this fantastic girl, along with her drawings. Whenever we think about overdose deaths in America, the sheer number—75,000—can make us indifferent. But when you can focus on one person and feel the love surrounding that life, you remember the value of this work.
Like in COVID, substance use disorders are a painful problem that we’re all experiencing in some way. They may have upset our lives. But they may have brought us together and, in many instances, brought out the best that humans can do. The best, to me, is caring for one another and taking the responsibility of helping those that are most vulnerable. I believe that science has a purpose. And here we have a purpose: to use science to bring solutions that can prevent and treat those suffering from substance use disorders.
Tabak: Thanks to both of you for this enlightening conversation.
 Drug overdose deaths, Centers for Disease Control and Prevention, February 22, 2022.
 Trends in drug overdose deaths among US adolescents, January 2010 to June 2021. Friedman J. et al. JAMA. 2022 Apr 12;327(14):1398-1400.
Video: Evening Plenary with NIH’s Lawrence Tabak, Nora Volkow, and Rebecca Baker (Rx and Illicit Drug Summit 2022)
SAMHSA’s National Helpline (Substance Abuse and Mental Health Services Administration, Rockville, MD)
Opioids (National Institute on Drug Abuse/NIH)
Rebecca Baker (HEAL/NIH)
Nora Volkow (NIDA)
As COVID-19 rapidly expanded throughout the world in April 2020, many in the biomedical technology community voiced significant concerns about the lack of available diagnostic tests. At that time, testing for SARS-CoV-2, the coronavirus that causes COVID-19, was conducted exclusively in clinical laboratories by order of a health-care provider. “Over the counter” (OTC) tests did not exist, and low complexity point of care (POC) platforms were rare. Fewer than 8 million tests were performed in the U.S. that month, and it was clear that we needed a radical transformation to make tests faster and more accessible.
By February 2022, driven by the Omicron variant surge, U.S. capacity had increased to a new record of more than 1.2 billion tests in a single month. Remarkably, the overwhelming majority of these—more than 85 percent—were “rapid tests” conducted in home and POC settings.
The story behind this practice-changing, “test-at-home” transformation is deeply rooted in technologic and manufacturing innovation. The NIH’s National Institute of Biomedical Imaging and Bioengineering (NIBIB), working collaboratively with multiple partners across NIH, government, academia, and the private sector, has been privileged to play a leading role in this effort via the Rapid Acceleration of Diagnostics (RADx®) initiative. On this two-year anniversary of RADx, we take a brief look back at its formation, impact, and potential for future growth.
On April 24, 2020, Congress recognized that testing was an urgent national need and appropriated $1.5 billion to NIH via an emergency supplement . The goal was to substantially increase the number, type, and availability of diagnostic tests in only five to six months. Since the “normal” commercialization cycle for this type of diagnostic technology is typically more than five years, we needed an entirely new approach . . . fast.
The RADx initiative was launched just five days after that challenging Congressional directive . Four NIH RADx programs were eventually created to support technology development and delivery, with the goal of matching test performance with community needs .The first two programs, RADx Tech and RADx Advanced Technology Platforms (ATP), were developed by NIBIB and focused on innovation for rapidly creating, scaling up, and deploying new technologies.
RADx Tech is built around NIBIB’s Point of Care Technologies Research Network (POCTRN) and includes core activities for technology review, test validation, clinical studies, regulatory authorization, and test deployment. Overall, the RADx Tech network includes approximately 900 participants from government, academia, and the private sector with unique capabilities and resources designed to decrease inherent risk and guide technologies from design and development to fully disseminated commercial products.
At the core of RADx Tech operations is the “innovation funnel” rapid review process, popularized as a shark tank . A total of 824 complete applications were submitted during two open calls in a four-month period, beginning April 2020 and during a one-month period in June 2021. Forty-seven projects received phase 1 funding to validate and lower the inherent risk of developing these technologies. Meanwhile, 50 companies received phase 2 contracts to support FDA authorization studies and manufacturing expansion 
Beyond test development, RADx Tech has evolved to become a key contributor to the U.S. COVID-19 response. The RADx Independent Test Assessment Program (ITAP) was launched in October 2021 to accelerate regulatory authorization of new tests as a joint effort with the Food and Drug Administration (FDA) . The ITAP acquires analytical and clinical performance data and works closely with FDA and manufacturers to shave weeks to months off the time it normally takes to receive Emergency Use Authorization (EUA).
The RADx Tech program also created a Variant Task Force to monitor the performance of tests against each new coronavirus “variant of concern” that emerges. This helps to ensure that marketed tests continue to remain effective. Other innovative RADx Tech projects include Say Yes! Covid Test, the first online free OTC test distribution program, and Project Rosa, which conducts real-time variant tracking across the country .
RADx Tech, by any measure, has exceeded even the most-optimistic expectations. In two years, RADx Tech-supported companies have received 44 EUAs and added approximately 2 billion tests and test products to the U.S. capacity. These remarkable numbers have steadily increased from more than16 million tests in September 2020, just five months after the program was established .
RADx Tech has also made significant contributions to the distribution of 1 billion free OTC tests via the government site, COVID.gov/tests. It has also provided critical guidance on serial testing and variants that have improved test performance and changed regulatory practice [9,10]. In addition, the RADx Mobile Application Reporting System (RADx MARS) reduces barriers to test reporting and test-to-treat strategies’ The latter offers immediate treatment options via telehealth or a POC location whenever a positive test result is reported. Finally, the When to Test website provides critical guidance on when and how to test for individuals, groups, and communities.
As we look to the future, RADx Tech has enormous potential to impact the U.S. response to other pathogens, diseases, and future pandemics. Major challenges going forward include improving home tests to work as well as lab platforms and building digital health networks for capturing and reporting test results to public health officials .
A recent editorial published in the journal Nature Biotechnology noted, “RADx has spawned a phalanx of diagnostic products to market in just 12 months. Its long-term impact on point of care, at-home, and population testing may be even more profound .” We are now poised to advance a new wave of precision medicine that’s led by innovative diagnostic technologies. It represents a unique opportunity to emerge stronger from the pandemic and achieve long-term impact.
 NIH mobilizes national innovation initiative for COVID-19 diagnostics, NIH news release, April 29, 2020.
 Rapid scaling up of Covid-19 diagnostic testing in the United States—The NIH RADx Initiative. Tromberg BJ, Schwetz TA, Pérez-Stable EJ, Hodes RJ, Woychik RP, Bright RA, Fleurence RL, Collins FS. N Engl J Med. 2020 Sep 10;383(11):1071-1077.
 We need more covid-19 tests. We propose a ‘shark tank’ to get us there. Alexander L. and Blunt R., Washington Post, April 20, 2020.
 RADx® Tech/ATP dashboard, National Institute of Biomedical Imaging and Bioengineering, NIH.
 New HHS actions add to Biden Administration efforts to increase access to easy-to-use over-the-counter COVID-19 tests. U.S. Department of Health and Human Services Press Office, October 25, 2021.
 A method for variant agnostic detection of SARS-CoV-2, rapid monitoring of circulating variants, detection of mutations of biological significance, and early detection of emergent variants such as Omicron. Lai E, et al. medRxiV preprint, January 9, 2022.
 Longitudinal assessment of diagnostic test performance over the course of acute SARS-CoV-2 infection. Smith RL, et al. J Infect Dis. 2021 Sep 17;224(6):976-982.
 Comparison of rapid antigen tests’ performance between Delta (B.1.61.7; AY.X) and Omicron (B.1.1.529; BA1) variants of SARS-CoV-2: Secondary analysis from a serial home self-testing study. Soni A, et al. MedRxiv preprint, March 2, 2022.
 Reporting COVID-19 self-test results: The next frontier. Health Affairs, Juluru K., et al. Health Affairs, February 11, 2022.
 Radical solutions. Nat Biotechnol. 2021 Apr;39(4):391.
Get Free At-Home COVID Tests (COVID.gov)
When to Test (Consortia for Improving Medicine with Innovation & Technology, Boston)
RADx Programs (NIH)
RADx® Tech and ATP Programs (National Institute of Biomedical Imaging and Biomedical Engineering/NIH)
[Note: Acting NIH Director Lawrence Tabak has asked the heads of NIH’s Institutes and Centers (ICs) to contribute occasional guest posts to the blog to highlight some of the interesting science that they support and conduct. This is the eighth in the series of NIH IC guest posts that will run until a new permanent NIH director is in place.]
Posted on by Lawrence Tabak, D.D.S., Ph.D.
More than 215 million people in the United States are now fully vaccinated against the SARS-CoV-2 virus responsible for COVID-19 . More than 40 percent—more than 94 million people—also have rolled up their sleeves for an additional, booster dose. Now, an NIH-funded study exploring how mRNA vaccines are performing over time comes as a reminder of just how important it will be to keep those COVID-19 vaccines up to date as coronavirus variants continue to circulate.
The results, published in the journal Science Translational Medicine, show that people who received two doses of either the Pfizer or Moderna COVID-19 mRNA vaccines did generate needed virus-neutralizing antibodies . But levels of those antibodies dropped considerably after six months, suggesting declining immunity over time.
The data also reveal that study participants had much reduced protection against newer SARS-CoV-2 variants, including Delta and Omicron. While antibody protection remained stronger in people who’d also had a breakthrough infection, even that didn’t appear to offer much protection against infection by the Omicron variant.
The new study comes from a team led by Shan-Lu Liu at The Ohio State University, Columbus. They wanted to explore how well vaccine-acquired immune protection holds up over time, especially in light of newly arising SARS-CoV-2 variants.
This is an important issue going forward because mRNA vaccines train the immune system to produce antibodies against the spike proteins that crown the surface of the SARS-CoV-2 coronavirus. These new variants often have mutated, or slightly changed, spike proteins compared to the original one the immune system has been trained to detect, potentially dampening the immune response.
In the study, the team collected serum samples from 48 fully vaccinated health care workers at four key time points: 1) before vaccination, 2) three weeks after the first dose, 3) one month after the second dose, and 4) six months after the second dose.
They then tested the ability of antibodies in those samples to neutralize spike proteins as a correlate for how well a vaccine works to prevent infection. The spike proteins represented five major SARS-CoV-2 variants. The variants included D614G, which arose very soon after the coronavirus first was identified in Wuhan and quickly took over, as well as Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529).
The researchers explored in the lab how neutralizing antibodies within those serum samples reacted to SARS-CoV-2 pseudoviruses representing each of the five variants. SARS-CoV-2 pseudoviruses are harmless viruses engineered, in this case, to bear coronavirus spike proteins on their surfaces. Because they don’t replicate, they are safe to study without specially designed biosafety facilities.
At any of the four time points, antibodies showed a minimal ability to neutralize the Omicron spike protein, which harbors about 30 mutations. These findings are consistent with an earlier study showing a significant decline in neutralizing antibodies against Omicron in people who’ve received the initial series of two shots, with improved neutralizing ability following an additional booster dose.
The neutralizing ability of antibodies against all other spike variants showed a dramatic decline from 1 to 6 months after the second dose. While there was a marked decline over time after both vaccines, samples from health care workers who’d received the Moderna vaccine showed about twice the neutralizing ability of those who’d received the Pfizer vaccine. The data also suggests greater immune protection in fully vaccinated healthcare workers who’d had a breakthrough infection with SARS-CoV-2.
In addition to recommending full vaccination for all eligible individuals, the Centers for Disease Control and Prevention (CDC) now recommends everyone 12 years and up should get a booster dose of either the Pfizer or Moderna vaccines at least five months after completing the primary series of two shots . Those who’ve received the Johnson & Johnson vaccine should get a booster at least two months after receiving the initial dose.
While plenty of questions about the durability of COVID-19 immunity over time remain, it’s clear that the rapid deployment of multiple vaccines over the course of this pandemic already has saved many lives and kept many more people out of the hospital. As the Omicron threat subsides and we start to look forward to better days ahead, it will remain critical for researchers and policymakers to continually evaluate and revise vaccination strategies and recommendations, to keep our defenses up as this virus continues to evolve.
 COVID-19 vaccinations in the United States. Centers for Disease Control and Prevention. February 27, 2022.
 Neutralizing antibody responses elicited by SARS-CoV-2 mRNA vaccination wane over time and are boosted by breakthrough infection. Evans JP, Zeng C, Carlin C, Lozanski G, Saif LJ, Oltz EM, Gumina RJ, Liu SL. Sci Transl Med. 2022 Feb 15:eabn8057.
 COVID-19 vaccine booster shots. Centers for Disease Control and Prevention. Feb 2, 2022.
COVID-19 Research (NIH)
Shan-Lu Liu (The Ohio State University, Columbus)
NIH Support: National Institute of Allergy and Infectious Diseases; National Cancer Institute; National Heart, Lung, and Blood Institute; Eunice Kennedy Shriver National Institute of Child Health and Human Development
Posted on by Lawrence Tabak, D.D.S., Ph.D.
The NIH continues to support the development of some very innovative therapies to control SARS-CoV-2, the coronavirus that causes COVID-19. One innovative idea involves a molecular decoy to thwart the coronavirus.
How’s that? The decoy is a specially engineered protein particle that mimics the 3D structure of the ACE2 receptor, a protein on the surface of our cells that the virus’s spike proteins bind to as the first step in causing an infection.
The idea is when these ACE2 decoys are administered therapeutically, they will stick to the spike proteins that crown the coronavirus (see image above). With its spikes covered tightly in decoy, SARS-CoV-2 has a more-limited ability to attach to the real ACE2 and infect our cells.
Recently, the researchers published their initial results in the journal Nature Chemical Biology, and the early data look promising . They found in mouse models of severe COVID-19 that intravenous infusion of an engineered ACE2 decoy prevented lung damage and death. Though more study is needed, the researchers say the decoy therapy could potentially be delivered directly to the lungs through an inhaler and used alone or in combination with other COVID-19 treatments.
The findings come from a research team at the University of Illinois Chicago team, led by Asrar Malik and Jalees Rehman, working in close collaboration with their colleagues at the University of Illinois Urbana-Champaign. The researchers had been intrigued by an earlier clinical trial testing the ACE2 decoy strategy . However, in this earlier attempt, the clinical trial found no reduction in mortality. The ACE2 drug candidate, which is soluble and degrades in the body, also proved ineffective in neutralizing the virus.
Rather than give up on the idea, the UIC team decided to give it a try. They engineered a new soluble version of ACE2 that structurally might work better as a decoy than the original one. Their version of ACE2, which includes three changes in the protein’s amino acid building blocks, binds the SARS-CoV-2 spike protein much more tightly. In the lab, it also appeared to neutralize the virus as well as monoclonal antibodies used to treat COVID-19.
To put it to the test, they conducted studies in mice. Normal mice don’t get sick from SARS-CoV-2 because the viral spike can’t bind well to the mouse version of the ACE2 receptor. So, the researchers did their studies in a mouse that carries the human ACE2 and develops a severe acute respiratory syndrome somewhat similar to that seen in humans with severe COVID-19.
In their studies, using both the original viral isolate from Washington State and the Gamma variant (P.1) first detected in Brazil, they found that infected mice infused with their therapeutic ACE2 protein had much lower mortality and showed few signs of severe acute respiratory syndrome. While the protein worked against both versions of the virus, infection with the more aggressive Gamma variant required earlier treatment. The treated mice also regained their appetite and weight, suggesting that they were making a recovery.
Further studies showed that the decoy bound to spike proteins from every variant tested, including Alpha, Beta, Delta and Epsilon. (Omicron wasn’t yet available at the time of the study.) In fact, the decoy bound just as well, if not better, to new variants compared to the original virus.
The researchers will continue their preclinical work. If all goes well, they hope to move their ACE2 decoy into a clinical trial. What’s especially promising about this approach is it could be used in combination with treatments that work in other ways, such as by preventing virus that’s already infected cells from growing or limiting an excessive and damaging immune response to the infection.
Last week, more than 17,500 people in the United States were hospitalized with severe COVID-19. We’ve got to continue to do all we can to save lives, and it will take lots of innovative ideas, like this ACE2 decoy, to put us in a better position to beat this virus once and for all.
 Engineered ACE2 decoy mitigates lung injury and death induced by SARS-CoV-2 variants.
Zhang L, Dutta S, Xiong S, Chan M, Chan KK, Fan TM, Bailey KL, Lindeblad M, Cooper LM, Rong L, Gugliuzza AF, Shukla D, Procko E, Rehman J, Malik AB. Nat Chem Biol. 2022 Jan 19.
COVID-19 Research (NIH)
Asrar Malik (University of Illinois Chicago)
Jalees Rehman (University of Illinois Chicago)
NIH Support: National Heart, Lung, and Blood Institute; National Institute of Allergy and Infectious Diseases