Can an “old school” vaccine address global inequities in Covid-19 vaccination?
When the COVID-19 pandemic began invading the world in late 2019, Peter Hotez and Maria Elena Bottazzi set out to create a low-cost vaccine that would help inoculate populations in low- and middle-income countries. The scientists, with their prior experience of developing inexpensive vaccines for the world’s poor, had anticipated that the global rollout of Covid-19 jabs would be marked with several inequities. They wanted to create a patent-free vaccine to bridge this gap, but the U.S. government did not seem impressed, forcing the researchers to turn to private philanthropies for funds.
Hotez and Bottazzi, both scientists at the Texas Children’s Hospital Center for Vaccine Development at Baylor College of Medicine, raised about $9 million in private funds. Meanwhile, the U.S. government’s contribution stood at $400,000.
“That was a very tough time early on in the pandemic, you know, trying to do the work and raise the money for it at the same time,” says Hotez, who was nominated in February for a Nobel Peace Prize with Bottazzi for their COVID-19 vaccine. He adds that at the beginning of the pandemic, governments emphasized speed, innovation and rapidly immunizing populations in North America and Europe with little consideration for poorer countries. “We knew this [vaccine] was going to be the answer to global vaccine inequality, but I just wish the policymakers had felt the same,” says Hotez.
Over the past two years, the world has witnessed 488 million COVID-19 infections and over 61 million deaths. Over 11 billion vaccine doses have been administered worldwide; however, the global rollout of COVID-19 vaccines is marked with alarming socio-economic inequities. For instance, 72 percent of the population in high-income countries has received at least one dose of the vaccine, whereas the number stands at 15 percent in low-income countries.
This inequity is worsening vulnerabilities across the world, says Lawrence Young, a virologist and co-lead of the Warwick Health Global Research Priority at the UK-based University of Warwick. “As long as the virus continues to spread and replicate, particularly in populations who are under-vaccinated, it will throw up new variants and these will remain a continual threat even to those countries with high rates of vaccination,” says Young, “Therefore, it is in all our interests to ensure that vaccines are distributed equitably across the world.”
“When your house is on fire, you don't call the patent attorney,” says Hotez. “We wanted to be the fire department.”
The vaccine developed by Hotez and Bottazzi recently received emergency use authorisation in India, which plans to manufacture 100 million doses every month. Dubbed ‘Corbevax’ by its Indian maker, Biological E Limited, the vaccine is now being administered in India to children aged 12-14. The patent-free arrangement means that other low- and middle-income countries could also produce and distribute the vaccine locally.
“When your house is on fire, you don't call the patent attorney, you call the fire department,” says Hotez, commenting on the intellectual property rights waiver. “We wanted to be the fire department.”
The Inequity
Vaccine equity simply means that all people, irrespective of their location, should have equal access to vaccines. However, data suggests that the global COVID-19 vaccine rollout has favoured those in richer countries. For instance, high-income countries like the UAE, Portugal, Chile, Singapore, Australia, Malta, Hong Kong and Canada have partially vaccinated over 85 percent of their populations. This percentage in poorer countries, meanwhile, is abysmally low – 2.1 percent in Yemen, 4.6 in South Sudan, 5 in Cameroon, 9.9 in Burkina Faso, 10 in Nigeria, 12 in Somalia, 12 in Congo, 13 in Afghanistan and 21 in Ethiopia.
In late 2019, scientists Peter Hotez and Maria Elena Bottazzi set out to create a low-cost vaccine that would help inoculate populations in low- and middle-income countries. In February, they were nominated for a Nobel Peace Prize.
Texas Children's Hospital
The COVID-19 vaccination coverage is particularly low in African countries, and according to Shabir Madhi, a vaccinologist at the University of the Witwatersrand, Johannesburg and co-director of African Local Initiative for Vaccinology Expertise, vaccine access and inequity remains a challenge in Africa. Madhi adds that a lack of vaccine access has affected the pandemic’s trajectory on the continent, but a majority of its people have now developed immunity through natural infection. “This has come at a high cost of loss of lives,” he says.
COVID-19 vaccines mean a significant financial burden for poorer countries, which spend an average of $41 per capita annually on health, while the average cost of every COVID-19 vaccine dose ranges between $2 and $40 in addition to a distribution cost of $3.70 per person for two doses. In December last year, the World Health Organisation (WHO) set a goal of immunizing 70 percent of the population of all countries by mid-2022. This, however, means that low-income countries would have to increase their health expenditure by an average of 56.6 percent to cover the cost, as opposed to 0.8 per cent in high-income countries.
Reflecting on the factors that have driven global inequity in COVID-19 vaccine distribution, Andrea Taylor, assistant director of programs at the Duke Global Health Innovation Center, says that wealthy nations took the risk of investing heavily in the development and scaling up of COVID-19 vaccines – at a time when there was little evidence to show that vaccines would work. This reserved a place for these nations at the front of the queue when doses started rolling off production lines. Lower-income countries, meanwhile, could not afford such investments.
“Now, however, global supply is not the issue,” says Taylor. “We are making plenty of doses to meet global need. The main problem is infrastructure to get the vaccine where it is most needed in a predictable and timely way and to ensure that countries have all the support they need to store, transport, and use the vaccine once it is received.”
Taufique Joarder, vice-chairperson of Bangladesh's Public Health Foundation, sees the need for more trials and data before Corbevax is made available to the general population.
In addition to global inequities in vaccination coverage, there are inequities within nations. Taufique Joarder, vice-chairperson of Bangladesh’s Public Health Foundation, points to the situation in his country, where vaccination coverage in rural and economically disadvantaged communities has suffered owing to weak vaccine-promotion initiatives and the difficulty many people face in registering online for jabs.
Joarder also cites the example of the COVID-19 immunization drive for children aged 12 years and above. “[Children] are given the Pfizer vaccine, which requires an ultralow temperature for storage. This is almost impossible to administer in many parts of the country, especially the rural areas. So, a large proportion of the children are being left out of vaccination,” says Joarder, adding that Corbevax, which is cheaper and requires regular temperature refrigeration “can be an excellent alternative to Pfizer for vaccinating rural children.”
Corbevax vs. mRNA Vaccines
As opposed to most other COVID-19 vaccines, which use the new Messenger RNA (mRNA) vaccine technology, Corbevax is an “old school” vaccine, says Hotez. The vaccine is made through microbial fermentation in yeast, similar to the process used to produce the recombinant hepatitis B vaccine, which has been administered to children in several countries for decades. Hence, says Hotez, the technology to produce Corbevax at large scales is already in place in countries like Vietnam, Bangladesh, India, Indonesia, Brazil, Argentina, among many others.
“So if you want to rapidly develop and produce and empower low- and middle-income countries, this is the technology to do it,” he says.
“Global access to high-quality vaccines will require serious investment in other types of COVID-19 vaccines," says Andrea Taylor.
The COVID-19 vaccines created by Pfizer-BioNTech and Moderna marked the first time that mRNA vaccine technology was approved for use. However, scientists like Young feel that there is “a need to be pragmatic and not seduced by new technologies when older, tried and tested approaches can also be effective.” Taylor, meanwhile, says that although mRNA vaccines have dominated the COVID-19 vaccine market in the U.S., “there is no clear grounding for this preference in the data we have so far.” She adds that there is also growing evidence that the immunity from these shots may not hold up as well over time as that of vaccines using different platforms.
“The mRNA vaccines are well suited to wealthy countries with sufficient ultra-cold storage and transportation infrastructure, but these vaccines are divas and do not travel well in the rest of the world,” says Taylor. “Global access to high-quality vaccines will require serious investment in other types of COVID-19 vaccines, such as the protein subunit platform used by Novavax and Corbevax. These require only standard refrigeration, can be manufactured using existing facilities all over the world, and are easy to transport.”
Joarder adds that Corbevax is cheaper due to the developers’ waived intellectual rights. It could also be used as a booster vaccine in Bangladesh, where only five per cent of the population has currently received booster doses. “If this vaccine is proved effective for heterologous boosting, [meaning] it works well and is well tolerated as a booster with other vaccines that are available in Bangladesh, this can be useful,” says Joarder.
According to Hotez, Corbevax can play several important roles - as a standalone adult or paediatric vaccine, and as a booster for other vaccines. Studies are underway to determine Corbevax’s effectiveness in these regards, he says.
Need for More Data
Biological E conducted two clinical trials involving 3000 subjects in India, and found Corbevax to be “safe and immunogenic,” with 90 percent effectiveness in preventing symptomatic infections from the original strain of COVID-19 and over 80 percent effectiveness against the Delta variant. The vaccine is currently in use in India, and according to Hotez, it’s in the pipeline at different stages in Indonesia, Bangladesh and Botswana.
However, Corbevax is yet to receive emergency use approval from the WHO. Experts such as Joarder see the need for more trials and data before it is made available to the general population. He says that while the WHO’s emergency approval is essential for global scale-up of the vaccine, we need data to determine age-stratified efficacy of the vaccine and whether it can be used for heterologous boosting with other vaccines. “According to the most recent data, the 100 percent circulating variant in Bangladesh is Omicron. We need to know how effective is Corbevax against the Omicron variant,” says Joarder.
Shabir Madhi, a vaccinologist at the University of the Witwatersrand, Johannesburg and co-director of the African Local Initiative for Vaccinology Expertise, says that a majority of people in Africa have now developed immunity through natural infection. “This has come at a high cost of loss of lives."
Shivan Parusnath
Others, meanwhile, believe that availing vaccines to poorer countries is not enough to resolve the inequity. Young, the Warwick virologist, says that the global vaccination rollout has also suffered from a degree of vaccine hesitancy, echoing similar observations by President Biden and Pfizer’s CEO. The problem can be blamed on poor communication about the benefits of vaccination. “The Corbevax vaccine [helps with the issues of] patent protection, vaccine storage and distribution, but governments need to ensure that their people are clearly informed.” Notably, however, some research has found higher vaccine willingness in lower-income countries than in the U.S.
Young also emphasized the importance of establishing local vaccination stations to improve access. For some countries, meanwhile, it may be too late. Speaking about the African continent, Madhi says that Corbevax has arrived following the peak of the crisis and won’t reverse the suffering and death that has transpired because of vaccine hoarding by high-income countries.
“The same goes for all the sudden donations from countries such as France - pretty much of little to no value when the pandemic is at its tail end,” says Madhi. “This, unfortunately, is a repeat of the swine flu pandemic in 2009, when vaccines only became available to Africa after the pandemic had very much subsided.”
Hyperbaric oxygen therapy could treat Long COVID, new study shows
Long COVID is not a single disease, it is a syndrome or cluster of symptoms that can arise from exposure to SARS-CoV-2, a virus that affects an unusually large number of different tissue types. That's because the ACE2 receptor it uses to enter cells is common throughout the body, and inflammation from the immune response fighting that infection can damage surrounding tissue.
One of the most widely shared groups of symptoms is fatigue and what has come to be called “brain fog,” a difficulty focusing and an amorphous feeling of slowed mental functioning and capacity. Researchers have tied these COVID-related symptoms to tissue damage in specific sections of the brain and actual shrinkage in its size.
When Shai Efrati, medical director of the Sagol Center for Hyperbaric Medicine and Research in Tel Aviv, first looked at functional magnetic resonance images (fMRIs) of patients with what is now called long COVID, he saw “micro infarcts along the brain.” It reminded him of similar lesions in other conditions he had treated with hyperbaric oxygen therapy (HBOT). “Once we saw that, we said, this is the type of wound we can treat. It doesn't matter if the primary cause is mechanical injury like TBI [traumatic brain injury] or stroke … we know how to oxidize them.”Efrati came to HBOT almost by accident. The physician had seen how it had helped heal diabetic ulcers and improved the lives of other patients, but he was busy with his own research. Then the director of his Tel Aviv hospital threatened to shut down the small HBOT chamber unless Efrati took on administrative responsibility for it. He reluctantly agreed, a decision that shifted the entire focus of his research.
“The main difference between wounds in the leg and wounds in the brain is that one is something we can see, it's tangible, and the wound in the brain is hidden,” says Efrati. With fMRIs, he can measure how a limited supply of oxygen in blood is shuttled around to fuel activity in various parts of the brain. Years of research have mapped how specific areas of the brain control activity ranging from thinking to moving. An fMRI captures the brain area as it’s activated by supplies of oxygen; lack of activity after the same stimuli suggests damage has occurred in that tissue. Suddenly, what was hidden became visible to researchers using fMRI. It helped to make a diagnosis and measure response to treatment.
HBOT is not a single thing but rather a tool, a process or approach with variations depending on the condition being treated. It aims to increase the amount of oxygen that gets to damaged tissue and speed up healing. Regular air is about 21 percent oxygen. But inside the HBOT chamber the atmospheric pressure can be increased to up to three times normal pressure at sea level and the patient breathes pure oxygen through a mask; blood becomes saturated with much higher levels of oxygen. This can defuse through the damaged capillaries of a wound and promote healing.
The trial
Efrati’s clinical trials started in December 2020, barely a year after SARS-CoV-2 had first appeared in Israel. Patients who’d experienced cognitive issues after having COVID received 40 sessions in the chamber over a period of 60 days. In each session, they spent 90 minutes breathing through a mask at two atmospheres of pressure. While inside, they performed mental exercises to train the brain. The only difference between the two groups of patients was that one breathed pure oxygen while the other group breathed normal air. No one knew who was receiving which level of oxygen.
The results were striking. Before and after fMRIs showed significant repair of damaged tissue in the brain and functional cognition tests improved substantially among those who received pure oxygen. Importantly, 80 percent of patients said they felt back to “normal,” but Efrati says they didn't include patient evaluation in the paper because there was no baseline data to show how they functioned before COVID. After the study was completed, the placebo group was offered a new round of treatments using 100 percent oxygen, and the team saw similar results.
Scans show improved blood flow in a patient suffering from Long Covid.
Sagol Center for Hyperbaric Medicine
Efrati's use of HBOT is part of an emerging geroscience approach to diseases associated with aging. These researchers see systems dysfunctions that are common to several diseases, such as inflammation, which has been shown to play a role in micro infarcts, heart disease and Alzheimer’s disease. Preliminary research suggests that HBOT can retard some underlying mechanisms of aging, which might address several medical conditions. However, the drug approval process is set up to regulate individual disease, not conditions as broad as aging, and so they concentrate on treating the low hanging fruit: disorders where effective treatments currently are limited and success might be demonstrated.
The key to HBOT's effectiveness is something called the hyperoxic-hypoxic paradox where a body does not react to an increase in available oxygen, only to a decrease, regardless of the starting point. That danger signal has a powerful effect on gene expression, resulting in changes in metabolism, and the proliferation of stem cells. That occurs with each cycle of 20 minutes of pure oxygen followed by 5 minutes of regular air circulating through the masks, while the chamber remains pressurized. The high levels of oxygen in the blood provide the fuel necessary for tissue regeneration.
The hyperbaric chamber that Efrati has built can hold a dozen patients and attending medical staff. Think of it as a pressurized airplane cabin, only with much more space than even in first class. In the U.S., people think of HBOT as “a sack of air or some tube that you can buy on Amazon” or find at a health spa. “That is total bullshit,” Efrati says. “It has to be a medical class center where a physician can lose their license if they are not operating it properly.”
Shai Efrati
Alexander Charney, a research psychiatrist at the Icahn School of Medicine at Mount Sinai in New York City, calls Efrati’s study thoughtful and well designed. But it demands a lot from patients with its intense number of sessions. Those types of regimens have proven difficult to roll out to large numbers of patients. Still, the results are intriguing enough to merit additional trials.
John J. Miller, a physician and editor in chief of Psychiatric Times, has seen “many physicians that use hyperbaric oxygen for various brain disorders such as TBI.” He is intrigued by Efrati's work and believes the approach “has great potential to help patients with long COVID whose symptoms are related to brain tissue changes.”
Efrati believes so much in the power of the hyperoxic-hypoxic paradox to heal a variety of tissue injuries that he is leading the medical advisory board at Aviv Clinic, an international network of clinics that are delivering HBOT treatments based on research conducted in Israel. His goal is to silence doubters by quickly opening about 50 such clinics worldwide, based on the model of standalone dialysis clinics in the United States. Sagol Center is treating 300 patients per day, and clinics have opened in Florida and Dubai. There are plans to open another in Manhattan.
A blood test may catch colorectal cancer before it's too late
Soon it may be possible to find different types of cancer earlier than ever through a simple blood test.
Among the many blood tests in development, researchers announced in July that they have developed one that may screen for early-onset colorectal cancer. The new potential screening tool, detailed in a study in the journal Gastroenterology, represents a major step in noninvasively and inexpensively detecting nonhereditary colorectal cancer at an earlier and more treatable stage.
In recent years, this type of cancer has been on the upswing in adults under age 50 and in those without a family history. In 2021, the American Cancer Society's revised guidelines began recommending that colorectal cancer screenings with colonoscopy begin at age 45. But that still wouldn’t catch many early-onset cases among people in their 20s and 30s, says Ajay Goel, professor and chair of molecular diagnostics and experimental therapeutics at City of Hope, a Los Angeles-based nonprofit cancer research and treatment center that developed the new blood test.
“These people will mostly be missed because they will never be screened for it,” Goel says. Overall, colorectal cancer is the fourth most common malignancy, according to the U.S. Centers for Disease Control and Prevention.
Goel is far from the only one working on this. Dozens of companies are in the process of developing blood tests to screen for different types of malignancies.
Some estimates indicate that between one-fourth and one-third of all newly diagnosed colorectal cancers are early-onset. These patients generally present with more aggressive and advanced disease at diagnosis compared to late-onset colorectal cancer detected in people 50 years or older.
To develop his test, Goel examined publicly available datasets and figured out that changes in novel microRNAs, or miRNAs, which regulate the expression of genes, occurred in people with early-onset colorectal cancer. He confirmed these biomarkers by looking for them in the blood of 149 patients who had the early-onset form of the disease. In particular, Goel and his team of researchers were able to pick out four miRNAs that serve as a telltale sign of this cancer when they’re found in combination with each other.
The blood test is being validated by following another group of patients with early-onset colorectal cancer. “We have filed for intellectual property on this invention and are currently seeking biotech/pharma partners to license and commercialize this invention,” Goel says.
He’s far from the only one working on this. Dozens of companies are in the process of developing blood tests to screen for different types of malignancies, says Timothy Rebbeck, a professor of cancer prevention at the Harvard T.H. Chan School of Public Health and the Dana-Farber Cancer Institute. But, he adds, “It’s still very early, and the technology still needs a lot of work before it will revolutionize early detection.”
The accuracy of the early detection blood tests for cancer isn’t yet where researchers would like it to be. To use these tests widely in people without cancer, a very high degree of precision is needed, says David VanderWeele, interim director of the OncoSET Molecular Tumor Board at Northwestern University’s Lurie Cancer Center in Chicago.
Otherwise, “you’re going to cause a lot of anxiety unnecessarily if people have false-positive tests,” VanderWeele says. So far, “these tests are better at finding cancer when there’s a higher burden of cancer present,” although the goal is to detect cancer at the earliest stages. Even so, “we are making progress,” he adds.
While early detection is known to improve outcomes, most cancers are detected too late, often after they metastasize and people develop symptoms. Only five cancer types have recommended standard screenings, none of which involve blood tests—breast, cervical, colorectal, lung (smokers considered at risk) and prostate cancers, says Trish Rowland, vice president of corporate communications at GRAIL, a biotechnology company in Menlo Park, Calif., which developed a multi-cancer early detection blood test.
These recommended screenings check for individual cancers rather than looking for any form of cancer someone may have. The devil lies in the fact that cancers without widespread screening recommendations represent the vast majority of cancer diagnoses and most cancer deaths.
GRAIL’s Galleri multi-cancer early detection test is designed to find more cancers at earlier stages by analyzing DNA shed into the bloodstream by cells—with as few false positives as possible, she says. The test is currently available by prescription only for those with an elevated risk of cancer. Consumers can request it from their healthcare or telemedicine provider. “Galleri can detect a shared cancer signal across more than 50 types of cancers through a simple blood draw,” Rowland says, adding that it can be integrated into annual health checks and routine blood work.
Cancer patients—even those with early and curable disease—often have tumor cells circulating in their blood. “These tumor cells act as a biomarker and can be used for cancer detection and diagnosis,” says Andrew Wang, a radiation oncologist and professor at the University of Texas Southwestern Medical Center in Dallas. “Our research goal is to be able to detect these tumor cells to help with cancer management.” Collaborating with Seungpyo Hong, the Milton J. Henrichs Chair and Professor at the University of Wisconsin-Madison School of Pharmacy, “we have developed a highly sensitive assay to capture these circulating tumor cells.”
Even if the quality of a blood test is superior, finding cancer early doesn’t always mean it’s absolutely best to treat it. For example, prostate cancer treatment’s potential side effects—the inability to control urine or have sex—may be worse than living with a slow-growing tumor that is unlikely to be fatal. “[The test] needs to tell me, am I going to die of that cancer? And, if I intervene, will I live longer?” says John Marshall, chief of hematology and oncology at Medstar Georgetown University Hospital in Washington, D.C.
Ajay Goel Lab
A blood test developed at the University of Texas MD Anderson Cancer Center in Houston helps predict who may benefit from lung cancer screening when it is combined with a risk model based on an individual’s smoking history, according to a study published in January in the Journal of Clinical Oncology. The personalized lung cancer risk assessment was more sensitive and specific than the 2021 and 2013 U.S. Preventive Services Task Force criteria.
The study involved participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial with a minimum of a 10 pack-year smoking history, meaning they smoked 20 cigarettes per day for ten years. If implemented, the blood test plus model would have found 9.2 percent more lung cancer cases for screening and decreased referral to screening among non-cases by 13.7 percent compared to the 2021 task force criteria, according to Oncology Times.
The conventional type of screening for lung cancer is an annual low-dose CT scan, but only a small percentage of people who are eligible will actually get these scans, says Sam Hanash, professor of clinical cancer prevention and director of MD Anderson’s Center for Global Cancer Early Detection. Such screening is not readily available in most countries.
In methodically searching for blood-based biomarkers for lung cancer screening, MD Anderson researchers developed a simple test consisting of four proteins. These proteins circulating in the blood were at high levels in individuals who had lung cancer or later developed it, Hanash says.
“The interest in blood tests for cancer early detection has skyrocketed in the past few years,” he notes, “due in part to advances in technology and a better understanding of cancer causation, cancer drivers and molecular changes that occur with cancer development.”
However, at the present time, none of the blood tests being considered eliminate the need for screening of eligible subjects using established methods, such as colonoscopy for colorectal cancer. Yet, Hanash says, “they have the potential to complement these modalities.”