vaccine
Tuberculosis: An Ancient Disease in Need of Modern Scientific Tools
Posted on by Anthony S. Fauci, M.D., National Institute of Allergy and Infectious Diseases
Although COVID-19 has dominated our attention for the past two years, tuberculosis (TB), an ancient scourge, remains a dominating infectious disease globally, with an estimated 10 million new cases and more than 1.3 million deaths in 2020. TB disproportionately afflicts the poor and has long been the leading cause of death in people living with HIV.
Unfortunately, during the global COVID-19 pandemic, recent gains in TB control have been stalled or reversed. We’ve seen a massive drop in new TB diagnoses, reflecting poor access to care and an uptick in deaths in 2020 [1].
We are fighting TB with an armory of old weapons inferior to those we have for COVID-19. The Bacillus Calmette–Guérin (BCG) vaccine, the world’s only licensed TB vaccine, has been in use for more than 100 years. While BCG is somewhat effective at preventing TB meningitis in children, it provides more limited durable protection against pulmonary TB in children and adults. More effective vaccination strategies to prevent infection and disease, decrease relapse rates, and shorten durations of treatment are desperately needed to reduce the terrible global burden of TB.
In this regard, over the past five years, several exciting research advances have generated new optimism in the field of TB vaccinology. Non-human primate studies conducted at my National Institute of Allergy and Infectious Diseases’ (NIAID) Vaccine Research Center and other NIAID-funded laboratories have demonstrated that effective immunity against infection is achievable and that administering BCG intravenously, rather than under the skin as it currently is given, is highly protective [2].
Results from a phase 2 trial testing BCG revaccination in adolescents at high risk of TB infection suggested this approach could help prevent TB [3]. In addition, a phase 2 trial of an experimental TB vaccine based on the recombinant protein M72 and an immune-priming adjuvant, AS01, also showed promise in preventing active TB disease in latently infected adults [4].
Both candidates are now moving on to phase 3 efficacy trials. The encouraging results of these trials, combined with nine other candidates currently in phase 2 or 3 studies [5], offer new hope that improved vaccines may be on the horizon. The NIAID is working with a team of other funders and investigators to analyze the correlates of protection from these studies to inform future TB vaccine development.
Even with these exciting developments, it is critical to accelerate our efforts to enhance and diversify the TB vaccine pipeline by addressing persistent basic and translational research gaps. To this end, NIAID has several new programs. The Immune Protection Against Mtb Centers are taking a multidisciplinary approach to integrate animal and human data to gain a comprehensive understanding of the immune responses required to prevent TB infection and disease.
This spring, NIAID will fund awards under the Innovation for TB Vaccine Discovery program that will focus on the discovery and early evaluation of novel TB vaccine candidates with the goal of diversifying the TB vaccine pipeline. Later this year, the Advancing Vaccine Adjuvant Research for TB program will systematically assess combinations of TB immunogens and adjuvants. Finally, NIAID’s well-established clinical trials networks are planning two new clinical trials of TB vaccine candidates.
As we look to the future, we must apply the lessons learned in the development of the COVID-19 vaccines to longstanding public health challenges such as TB. COVID-19 vaccine development was hugely successful due to the use of novel vaccine platforms, structure-based vaccine design, community engagement for rapid clinical trial enrollment, real-time data sharing with key stakeholders, and innovative trial designs.
However, critical gaps remain in our armamentarium. These include the harnessing the immunology of the tissues that line the respiratory tract to design vaccines more adept at blocking initial infection and transmission, employing thermostable formulations and novel delivery systems for resource-limited settings, and crafting effective messaging around vaccines for different populations.
As we work to develop better ways to prevent, diagnose, and treat TB, we will do well to remember the great public health icon, Paul Farmer, who tragically passed away earlier this year at a much too young age. Paul witnessed firsthand the devastating consequences of TB and its drug resistant forms in Haiti, Peru, and other parts of the world.
In addition to leading efforts to improve how TB is treated, Paul provided direct patient care in underserved communities and demanded that the world do more to meet their needs. As we honor Paul’s legacy, let us accelerate our efforts to find better tools to fight TB and other diseases of global health importance that exact a disproportionate toll among the poor and underserved.
References:
[1] Global tuberculosis report 2021. WHO. October 14, 2021.
[2] Prevention of tuberculosis in macaques after intravenous BCG immunization. Darrah PA, Zeppa JJ, Maiello P, Hackney JA, Wadsworth MH,. Hughes TK, Pokkali S, Swanson PA, Grant NL, Rodgers MA, Kamath M, Causgrove CM, Laddy DJ, Bonavia A, Casimiro D, Lin PL, Klein E, White AG, Scanga CA, Shalek AK, Roederer M, Flynn JL, and Seder RA. Nature. 2020 Jan 1; 577: 95–102.
[3] Prevention of M. tuberculosis Infection with H4:IC31 vaccine or BCG revaccination. Nemes E, Geldenhuys H, Rozot V, Rutkowski KT, Ratangee F,Bilek N., Mabwe S, Makhethe L, Erasmus M, Toefy A, Mulenga H, Hanekom WA, et al. N Engl J Med 2018; 379:138-149.
[4] Final analysis of a trial of M72/AS01E vaccine to prevent tuberculosis. Tait DR, Hatherill M, Van Der Meeren O, Ginsberg AM, Van Brakel E, Salaun B, Scriba TJ, Akite EJ, Ayles HM, et al.
[5] Pipeline Report 2021: Tuberculosis Vaccines. TAG. October 2021.
Links:
Tuberculosis (National Institute of Allergy and Infectious Diseases/NIH)
NIAID Strategic Plan for Tuberculosis Research
Immune Mechanisms of Protection Against Mycobacterium tuberculosis Centers (IMPAc-TB) (NIAID)
Partners in Health (Boston, MA)
[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 seventh in the series of NIH IC guest posts that will run until a new permanent NIH director is in place.]
The Latest on COVID-19 Boosters
Posted on by Dr. Francis Collins
More than 180 million Americans, including more than 80 percent of people over age 65, are fully vaccinated against the SARS-CoV-2 virus responsible for COVID-19. There’s no question that full vaccination is the best way to protect yourself against this devastating virus and reduce your chances of developing severe or long-lasting illness if you do get sick. But, to stay ahead of this terrible virus, important questions do remain. A big one right now is: How soon will booster shots be needed and for whom?
The answers to this question will continue to evolve as more high-quality data become available. But here’s what we know right now for the Pfizer-BioNTech booster. Late last week, Dr. Rochelle Walensky, the Director of the Centers for Disease Control and Prevention (CDC), recommended that:
- Those 65 years and older and residents in long-term care settings should receive a booster shot at least 6 months after being fully vaccinated with the Pfizer-BioNTech vaccine,
- People aged 50–64 years with underlying medical conditions should receive a booster shot at least 6 months after being fully vaccinated with the Pfizer-BioNTech vaccine,
- Individuals aged 18–49 years with underlying medical conditions may receive a booster shot at least 6 months after getting fully vaccinated with their Pfizer-BioNTech vaccine, based on their individual benefits and risks.
- Frontline workers who received the Pfizer-BioNTech vaccine may receive a booster. This group includes anyone age 18 through 64 whose frequent institutional or occupational exposure to SARS-CoV-2 puts them at high risk of COVID-19. [1]
Taken together, these CDC recommendations are in line with those issued two days earlier by the Food and Drug Administration (FDA) [2].
Some of the most-compelling data that was under review came from an Israeli study, published recently in the New England Journal of Medicine, that explored the benefit of booster shots for older people [3]. Israel, with a population of around 9 million, has a national health system and one of the world’s highest COVID-19 vaccination rates. That country’s vaccination campaign, based solely on Pfizer-BioNTech, was organized early in 2021, and so its experience is about three months ahead of ours here in the U.S. These features, plus some of the world’s largest integrated health record databases, have made Israel an important source of early data on how the Pfizer-BioNTech mRNA vaccine can be expected to work in the real world over time.
Earlier this year, Israeli public health officials noted evidence for an increased number of breakthrough infections, some of which were severe. So, at the end of July 2021, Israel approved the administration of third doses, or “boosters,” of the Pfizer-BioNTech vaccine for people ages 60 and up who had received their second dose at least five months before.
To find out how well these booster shots worked to bolster immune protection against COVID-19, researchers looked to more than 1.1 million fully vaccinated people who were at least 60 years old. They compared the rate of confirmed COVID-19 infection and severe illness from the end of July to the end of August among people who’d received a booster at least 12 days earlier with those who hadn’t gotten boosters.
Nearly 13,500 older individuals who’d been fully vaccinated before March 2021, got a breakthrough infection during the two months of study. Importantly, the rate of confirmed infection in the group that got boosters was 10 times lower on average than in the group that didn’t get boosters. The data on severe illness looked even better. Of course, there could be other factors at play that weren’t accounted for in the study, but the findings certainly suggest that a third Pfizer shot is safe and effective for older people.
Though the Israeli studies on booster shots are a little ahead of the international pack, we are starting to see results from the research underway in the U.S. Last week, for example, Johnson & Johnson announced new data in support of boosters to improve and extend immune protection in those who received its single-dose COVID-19 vaccine [4]. For people who received the Moderna mRNA vaccine, the company has already submitted its data to the FDA for booster authorization. A decision is expected soon.
As the critical evidence on boosters continues to emerge, the most important way to avoid another winter surge of COVID-19 is to follow all public health recommendations. Most importantly, that includes getting fully vaccinated if you haven’t already, and encouraging others around you to do the same. If you’re currently eligible for a booster shot, they are available at 80,000 locations across the nation, and can help you stay healthy and well for the coming holiday season.
For others eager to do everything possible to protect themselves, their families, and their communities against this terrible virus—but who are not yet eligible for a booster—sit tight for now. The data on booster shots are still coming in for folks like me who were immunized with the Moderna or Johnson & Johnson vaccines. It’s likely that the FDA and CDC will widen their recommendations in the coming weeks.
In the meantime, the Delta variant is still out there and circulating. That makes it critical to maintain vigilance. Wear a mask in indoor spaces, keep a physical distance from others, and remember to wash your hands frequently. We are all really tired of COVID-19, but patience is still required as we learn more about how best to stay ahead of this virus.
References:
[1] CDC statement on ACIP booster recommendations. Centers for Disease Control and Prevention news release. September 24, 2021
[2] FDA authorizes booster dose of Pfizer-BioNTech COVID-19 vaccine for certain populations. Food and Drug Administration news release. September 22, 2021
[3] Protection of BNT162b2 vaccine booster against Covid-19 in Israel. Bar-On YM, Goldberg Y, Mandel M, Bodenheimer O, Freedman L, Kalkstein N, Mizrahi B, Alroy-Preis S, Ash N, Milo R, Huppert A. N Engl J Med. 2021 Sep 15.
[4] Johnson & Johnson announces real-world evidence and Phase 3 data confirming strong and long-lasting protection of single-shot COVID-19 vaccine in the U.S. Johnson & Johnson. September 21, 2021.
Links:
COVID-19 Research (NIH)
Breakthrough Infections in Vaccinated People Less Likely to Cause ‘Long COVID’
Posted on by Dr. Francis Collins
There’s no question that vaccines are making a tremendous difference in protecting individuals and whole communities against infection and severe illness from SARS-CoV-2, the coronavirus that causes COVID-19. And now, there’s yet another reason to get the vaccine: in the event of a breakthrough infection, people who are fully vaccinated also are substantially less likely to develop Long COVID Syndrome, which causes brain fog, muscle pain, fatigue, and a constellation of other debilitating symptoms that can last for months after recovery from an initial infection.
These important findings published in The Lancet Infectious Diseases are the latest from the COVID Symptom Study [1]. This study allows everyday citizens in the United Kingdom to download a smartphone app and self-report data on their infection, symptoms, and vaccination status over a long period of time.
Previously, the study found that 1 in 20 people in the U.K. who got COVID-19 battled Long COVID symptoms for eight weeks or more. But this work was done before vaccines were widely available. What about the risk among those who got COVID-19 for the first time as a breakthrough infection after receiving a double dose of any of the three COVID-19 vaccines (Pfizer, Moderna, AstraZeneca) authorized for use in the U.K.?
To answer that question, Claire Steves, King’s College, London, and colleagues looked to frequent users of the COVID Symptom Study app on their smartphones. In its new work, Steves’ team was interested in analyzing data submitted by folks who’d logged their symptoms, test results, and vaccination status between December 9, 2020, and July 4, 2021. The team found there were more than 1.2 million adults who’d received a first dose of vaccine and nearly 1 million who were fully vaccinated during this period.
The data show that only 0.2 percent of those who were fully vaccinated later tested positive for COVID-19. While accounting for differences in age, sex, and other risk factors, the researchers found that fully vaccinated individuals who developed breakthrough infections were about half (49 percent) as likely as unvaccinated people to report symptoms of Long COVID Syndrome lasting at least four weeks after infection.
The most common symptoms were similar in vaccinated and unvaccinated adults with COVID-19, and included loss of smell, cough, fever, headaches, and fatigue. However, all of these symptoms were milder and less frequently reported among the vaccinated as compared to the unvaccinated.
Vaccinated people who became infected were also more likely than the unvaccinated to be asymptomatic. And, if they did develop symptoms, they were half as likely to report multiple symptoms in the first week of illness. Another vaccination benefit was that people with a breakthrough infection were about a third as likely to report any severe symptoms. They also were more than 70 percent less likely to require hospitalization.
We still have a lot to learn about Long COVID, and, to get the answers, NIH has launched the RECOVER Initiative. The initiative will study tens of thousands of COVID-19 survivors to understand why many individuals don’t recover as quickly as expected, and what might be the cause, prevention, and treatment for Long COVID.
In the meantime, these latest findings offer the encouraging news that help is already here in the form of vaccines, which provide a very effective way to protect against COVID-19 and greatly reduce the odds of Long COVID if you do get sick. So, if you haven’t done so already, make a plan to protect your own health and help end this pandemic by getting yourself fully vaccinated. Vaccines are free and available near to you—just go to vaccines.gov or text your zip code to 438829.
Reference:
[1] Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app: a prospective, community-based, nested, case-control study. Antonelli M, Penfold RS, Merino J, Sudre CH, Molteni E, Berry S, Canas LS, Graham MS, Klaser K, Modat M, Murray B, Kerfoot E, Chen L, Deng J, Österdahl MF, Cheetham NJ, Drew DA, Nguyen LH, Pujol JC, Hu C, Selvachandran S, Polidori L, May A, Wolf J, Chan AT, Hammers A, Duncan EL, Spector TD, Ourselin S, Steves CJ. Lancet Infect Dis. 2021 Sep 1:S1473-3099(21)00460-6.
Links:
COVID-19 Research (NIH)
Claire Steves (King’s College London, United Kingdom)
A Double Thumbs Up
Posted on by Dr. Francis Collins
Nanoparticle Technology Holds Promise for Protecting Against Many Coronavirus Strains at Once
Posted on by Dr. Francis Collins
It’s truly encouraging to witness people all across our nation rolling up their sleeves to get their COVID-19 vaccines. That is our best chance to end this pandemic. But this is the third coronavirus to emerge and cause serious human illness in the last 20 years, and it’s probably not the last. So, this is also an opportunity to step up our efforts to develop vaccines to combat future strains of disease-causing coronavirus. With this in mind, I’m heartened by a new NIH-funded study showing the potential of a remarkably adaptable, nanoparticle-based approach to coronavirus vaccine development [1].
Both COVID-19 vaccines currently authorized for human use by the Food and Drug Administration (FDA) work by using mRNA to instruct our cells to make an essential portion of the spike protein of SARS-CoV-2, which is the novel coronavirus that causes COVID-19. As our immune system learns to recognize this protein fragment as foreign, it produces antibodies to attack SARS-CoV-2 and prevent COVID-19. What makes the new vaccine technology so powerful is that it raises the possibility of training the immune system to recognize not just one strain of coronavirus—but up to eight—with a single shot.
This approach has not yet been tested in people, but when a research team, led by Pamela Bjorkman, California Institute of Technology, Pasadena, injected this new type of vaccine into mice, it spurred the production of antibodies that react to a variety of different coronaviruses. In fact, some of the mouse antibodies proved to be reactive to related strains of coronavirus that weren’t even represented in the vaccine. These findings suggest that if presented with multiple different fragments of the spike protein’s receptor binding domain (RBD), which is what SARS-like coronaviruses use to infect human cells, the immune system may learn to recognize common features that might protect against as-yet unknown, newly emerging coronaviruses.
This new work, published in the journal Science, utilizes a technology called a mosaic nanoparticle vaccine platform [1]. Originally developed by collaborators at the University of Oxford, United Kingdom, the nanoparticle component of the platform is a “cage” made up of 60 identical proteins. Each of those proteins has a small protein tag that functions much like a piece of Velcro®. In their SARS-CoV-2 work, Bjorkman and her colleagues, including graduate student Alex A. Cohen, engineered multiple different fragments of the spike protein so each had its own Velcro-like tag. When mixed with the nanoparticle, the spike protein fragments stuck to the cage, resulting in a vaccine nanoparticle with spikes representing four to eight distinct coronavirus strains on its surface. In this instance, the researchers chose spike protein fragments from several different strains of SARS-CoV-2, as well as from other related bat coronaviruses thought to pose a threat to humans.
The researchers then injected the vaccine nanoparticles into mice and the results were encouraging. After inoculation, the mice began producing antibodies that could neutralize many different strains of coronavirus. In fact, while more study is needed to understand the mechanisms, the antibodies responded to coronavirus strains that weren’t even represented on the mosaic nanoparticle. Importantly, this broad antibody response came without apparent loss in the antibodies’ ability to respond to any one particular coronavirus strain.
The findings raise the exciting possibility that this new vaccine technology could provide protection against many coronavirus strains with a single shot. Of course, far more study is needed to explore how well such vaccines work to protect animals against infection, and whether they will prove to be safe and effective in people. There will also be significant challenges in scaling up manufacturing. Our goal is not to replace the mRNA COVID-19 vaccines that scientists developed at such a remarkable pace over the last year, but to provide much-needed vaccine strategies and tools to respond swiftly to the emerging coronavirus strains of the future.
As we double down on efforts to combat COVID-19, we must also come to grips with the fact that SARS-CoV-2 isn’t the first—and surely won’t be the last—novel coronavirus to cause disease in humans. With continued research and development of new technologies such as this one, the hope is that we will come out of this terrible pandemic better prepared for future infectious disease threats.
References:
[1] Mosaic RBD nanoparticles elicit neutralizing antibodies against SARS-CoV-2 and zoonotic coronaviruses. Cohen AA, Gnanapragasam PNP, Lee YE, Hoffman PR, Ou S, Kakutani LM, Keeffe JR, Barnes CO, Nussenzweig MC, Bjorkman PJ. Science. 2021 Jan 12.
Links:
COVID-19 Research (NIH)
Bjorkman Lab (California Institute of Technology, Pasadena)
NIH Support: National Institute of Allergy and Infectious Diseases
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