Tag: vaccines

UN Urges Group B Streptococcus Vaccine to Protect Babies

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There is an urgent need for vaccines against Group B streptococcus, a major cause of preterm births, disability and infant mortality worldwide, according to a UN-backed report published on Wednesday.

Group B streptococcus (GBS) is a gram-positive bacteria that colonises the gastrointestinal and genitourinary tract. It can be transmitted in utero, is linked to around 150 000 infant deaths each year, more than half a million preterm births and significant long-term disability.

The report by the World Health Organization (WHO) and the London School of Hygiene & Tropical Medicine (LSHTM) updates 2017 estimates, and reveals that the global burden of GBS is far higher than was previously recognised.

“This new research shows that Group B strep is a major and underappreciated threat to newborn survival and wellbeing, bringing devastating impacts for so many families globally,” said Dr Phillipp Lambach, Medical Officer from WHO’s Immunization, Vaccines and Biologicals department.

The report is the first to quantify the major contribution of GBS to preterm births, and to neurological impairments such as cerebral palsy, hearing and vision loss, that can occur following infection.

Around 15% of all pregnant women worldwide, nearly 20 million annually, carry the GBS bacterium in their vagina, which can then spread to a foetus, or to newborns during labour. At present, GBS disease prevention in newborns is by administering antibiotic prophylaxis to women during labour, if the bacterium is detected during pregnancy.

However, significant health risks remain, as this intervention is unlikely to prevent most GBS-associated stillbirths, preterm births, or GBS disease that occurs later after birth.

“It is difficult to describe the breadth or depth of the grief when your child dies, or the accompanying guilt, and how it changes you, your family, and your relationships forever,” said Debbie Forwood, whose daughter Ada was stillborn after she developed a GBS infection.

Vaccine development urged
GBS burden is highest in low and middle-income countries, where screening and treatment are most challenging to implement, with regions such as sub-Saharan Africa having the highest rates of maternal GBS.
Now is the time for action, said Joy Lawn, an LSHTM Professor who contributed to the report.  While several candidate GBS vaccines are in development, none are yet available despite decades in the pipeline. The report calls for stepping up development of an effective GBS vaccine that could be administered to expectant mothers during routine pregnancy checkups.

The partners estimate more than 50 000 GBS-related deaths, and over 170 000 pre-term births, could be avoided if over 70 per cent of pregnant women were vaccinated.

Such protection could also be highly cost-effective, they added.  Net benefits from a year of maternal vaccinations could reach as high as $17 billion, accruing over several years, provided doses are affordably priced. For Ms. Forwood, this would be a bittersweet development.

“Only a GBS vaccine could have saved Ada.  When a vaccine can be widely rolled out, I will weep and scream with the unfairness that it came too late for her, and for all the other babies who are needlessly suffering and dying every year that it is delayed,” she said.

“But I will also weep with joy that in the future, many more will live, and their families will be saved from the living hell that is the death of a child.”

Source: UN News

Vaccine to Prevent Hookworm Infection Could be a ‘Gamechanger’

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There’s been a significant breakthrough in the development of a vaccine to prevent hookworm infection – a parasite which causes serious disease in tens of millions of people globally.

Mouse trials of the vaccine candidate in mice indicate that it is more than twice as effective than current alternatives. The results were published in Vaccines.

Professor Istvan Toth from UQ’s School of Chemistry and Molecular Biology said the easy oral administration would be a gamechanger for developing countries.

“Our vaccine candidate can be orally self-administered, bypassing the need for trained medical staff, and means there’s no requirement for special storage, enabling it to reach large, isolated populations,” Professor Toth said, noting that costs can be significantly reduced.

A serious healthcare challenge
About 500 million people worldwide are infected with hookworm, which lives within the human intestine, feeding on the host’s blood, digested through a special set of enzymes.

It’s often found in regions with poor water quality, sanitation, and hygiene – greatly impacting on the physical and cognitive development of children and increasing the risk of mortality and miscarriage.

UQ’s trials in mice showed significant improvements on an alternative vaccine candidate which only achieved a 30 to 50 per cent reduction in the number of worms.

“The UQ-developed vaccine resulted in an impressive 94% worm reduction in mice,” Professor Toth said, noting that besides being easier to deliver, it “triggers a staggeringly good immune response.”

Hookworms lose their appetite
Paper co-author Dr Mariusz Skwarczynski said the hookworm’s digestion enzyme (APR 1) was the target.

“When the function of these enzymes is blocked, the parasite starves,” Dr Skwarczynski said.

“Our vaccine produces antibodies against the hookworm enzymes responsible for the digestion of blood – they simply stop being able to eat properly.”

The researchers plan to continue working on and refining the vaccine candidate in preclinical development settings, to ensure its safety and efficacy, before beginning human clinical trials.

Source: University of Queensland

Creating a Cross-protective Coronavirus Vaccine

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Researchers have found that by targeting the core region of the spike protein receptor-binding domain, which remains structurally similar among SARS-related viruses, they can create a vaccine that offers cross-protection against SARS coronaviruses.

The COVID pandemic, caused by the β-coronavirus SARS-CoV-2, alerted the world to the seriousness of the threat posed by novel viruses. To protect against similar future outbreaks, there is an urgent need for broadly protective vaccines against SARS-related coronaviruses. In a recent study published in Journal of Experimental Medicine, a team of researchers led by Osaka University generated an immune antigen that was based on a conserved protein on the surface of SARS-related viruses. In mice immunised with this antigen, cross-neutralising antibodies against SARS-related viruses were elicited.

The coronavirus spike protein, specifically the receptor-binding domain (RBD) of spike protein that enables the virus to attach to host cells is a target for the development of neutralising antibodies, and a promising vaccine candidate. The RBD is made of two regions: the head, which is more immune-reactive and so has the most antibodies created for it, and the core. The head however changes more rapidly, while the core region is more stable amongst SARS-related viruses. Antibodies raised against this conserved core region of the RBD can therefore generate cross-protection against multiple SARS-related viruses.

As lead authors Ryo Shinnakasu and Shuhei Sakakibara explained, “The key to generating a vaccine that offers broad cross-protection among related viruses is to target a structure on the viral surface that is highly conserved. Our approach was to generate a vaccine in which the non-conserved region was masked from the immune system by the introduction of a carbohydrate molecule (or glycan) by a method known as glycan engineering. This would in turn expose the conserved core region of the RBD of spike protein.” When used to immunise mice, protective antibodies were induced that recognised the RBD core region not only of SARS-CoV-2 but also of other SARS-related viruses, such as bat SARS-like coronavirus, WIV1-CoV.

This finding is particularly promising because it demonstrates the potential for highly protective vaccines against various SARS-related viruses. As senior author Tomohiro Kurosaki warned, “Despite the existence of effective vaccines against current viruses, there is potential for the emergence of similar viruses in the future. This highlights the real need for broadly protective vaccines against SARS-related coronaviruses.”

The novel approach of vaccine design that they describe may help protect against a future global health crisis such as that experienced during the COVID pandemic.

Source: Osaka University

Are Combination COVID Vaccines the Wave of the Future?

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An article in MedPage Today examines the potential for combination COVID vaccines.

Novavax and Moderna have recently announced the development of combination vaccines that would protect not only against COVID, but also against influenza. In the case of Moderna, they are testing a combination vaccine that also includes protection against respiratory syncytial virus (RSV) — a viral illness for which no vaccine is currently available, which would be a major advancement Because COVID vaccines can be administered simultaneously with other vaccines, albeit in separate injections, the next step would be to co-formulate them in the same injection with other vaccinations.

Combination vaccines are extremely valuable for several reasons, chief among them is convenience. If, during one visit to a provider, a person can get multiple vaccinations, it ensures uptake of all those vaccines without the need to schedule multiple visits or use multiple injections. A single needle puncture is better than multiple punctures, even for those who are not needle phobic. As more vaccines are developed, combination vaccines become critical in getting doses into arms with the minimum number of injections.

Combination vaccines have been around for a long time, and are the mainstay of routine vaccination. Today, children receive several combination vaccinations including the well-known MMR (measles, mumps, rubella) and DTap (diphtheria, tetanus, acellular pertussis). These types of vaccines have a long history with DTP, the first combination vaccine used in humans, dating to the 1940s. Pentacel immunises against five different pathogens at once. Such convenience, especially with hard-to-reach populations, is invaluable. Adults also receive combination vaccinations, most prominently the Tdap (tetanus, diphtheria, acellular pertussis) boosters. Many physicians wish there were more combination vaccination products available because they have the potential to significantly increase vaccination rates.

It is of course necessary to determine that combination vaccines are safe and effective. Because they contain more antigen, reactions at injection sites might be more pronounced, fever might be slightly higher, and tolerability lower. To avoid the risk of febrile seizures, infants do not get the MMRV (measles, mumps, rubella, varicella) vaccine, instead getting varicella separately.
A combination vaccine’s components should not interfere with each other or blunt the immune response. This immune interference was a concern with vaccines combining Hib with DTap. For instance, vaccines with different storage conditions or delivery mechanisms (eg, subcutaneous vs intra-muscular; lipid nanoparticle encased) may not be the best candidates to combine. It is also important to combine vaccines that have compatible age or time-based schedules for administration.

As scientists explore a combination flu and COVID vaccine, they will be looking closely at all of these safety and efficacy considerations.

It’s important to emphasize, considering widespread disinformation from the anti-vaccine movement, that there is no “antigen overload” risk with combination vaccines. The human immune system is bombarded with antigens every day. We even become bacteremic, when we brush our teeth, or eat. The antigens contained in a combination vaccine are miniscule by comparison. In fact, the first ever vaccine, for smallpox, was packed with particles and impurities but was still incredibly efficacious and led to control and eventual elimination of one of humanity’s deadliest scourges.

It is likely to see individual attacks on COVID combination vaccines long before they are even available. We’ve previously seen such attacks on the MMR vaccine — these attacks became so pervasive that manufacturers started to produce the single vaccines again to placate people who were the victims of a concerted disinformation campaign. But we can learn from these past challenges. It will be important to fight disinformation about the COVID-19 combination vaccines early on, and encourage their uptake when they become available.

But one thing is certain: we should aim to make COVID vaccination convenient, normal, and easy. Proactively working on next generation vaccines that do this by combining with other vaccinations, altering the mode of delivery (eg, oral or nasal vaccines), or simplifying storage requirements are important tasks.

Source: MedPage Today

HPV Vaccine to Cause Drop in Oropharyngeal Cancers

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Vaccinations against human papillomavirus (HPV), a major cause of oropharyngeal cancers, are expected to yield significant reductions in the rates of these cancers in the US after 2045, according to a new study.

The most common sexually transmitted infectious virus worldwide, HPV infection is often silent, and while most infections clear, some are chronic and can trigger cancers including mouth and throat (oropharyngeal), and cervical cancer as they disrupt DNA and inhibit tumour-suppressor proteins in infected cells. While there is no cure for existing HPV infections, vaccines can prevent new infections. The study appears online in JAMA Oncology.

“We estimate that most of the oropharyngeal cancers from 2018 to 2045 will occur among people who are 55 years and older and have not been vaccinated,” said study lead author Yuehan Zhang, a PhD candidate in the research group of Gypsyamber D’Souza, PhD, professor in the Department of Epidemiology at the Bloomberg School.

“HPV vaccination is going to work to prevent oropharyngeal cancers, but it will take time to see that impact, because these cancers mostly occur in middle age,” Prof D’Souza said.

Oropharyngeal cancer is the most common HPV-related cancer. Vaccination, though effective in prevention, has no effect against established HPV infections or against cells that have been transformed by HPV and are on their way to forming tumours, therefore recommended mainly for the young not yet exposed to sexually transmitted HPV. (People who were adults when the vaccine became available mostly did not receive it and remain at risk for these cancers)

In the new study, researchers at the Johns Hopkins Bloomberg School of Public Health analysed national databases on oropharyngeal cancer cases and HPV vaccinations, and projected the impact of HPV vaccination on the rates of these cancers in different age groups. They estimated that the oropharyngeal cancer rate would nearly halve between 2018 and 2045 among people ages 36–45. However, they also projected that the rate in the overall population would stay about the same from 2018-2045, due to still-rising rates of these cancers in older people, where most of these cancers occur.

The results suggest, though, that by 2045 HPV vaccination will have begun to make a significant impact. “Our projections suggest that by around 2033, nearly 100 cases of oropharyngeal cancer will be prevented each year, but by 2045 that figure will have increased by about ten times,” Zhang said.

Source: Johns Hopkins University Bloomberg School of Public Health

MMR and Tdap Vaccines May Confer Some COVID Protection

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Mounting evidence shows that the Measles-Mumps-Rubella (MMR) and Tetanus-Diphtheria-Pertussis (Tdap) vaccines confer limited protection against COVID.

The MMR vaccine, given during early childhood, and Tdap vaccine, given every 10 years, elicit protective responses against the diseases they are designed for. It’s possible that they also elicit cross-reactive memory T cells that can respond to antigens that are present in other pathogens — including the viral antigens in SARS-CoV-2. The idea is that pre-existing memory T cells generated by prior MMR or Tdap vaccination and activated by SARS-CoV-2 infection give the immune system a head start in responding to SARS-CoV-2, lowering the risk of severe COVID.

To find out if the MMR and Tdap vaccines provide additional protection against COVID, researchers at Brigham and Women’s Hospital performed laboratory-based analyses with new techniques to detect and characterise T cell responses to antigens. They applied these techniques to measure T cell responses isolated from the blood of COVID convalescent patients and patients vaccinated against COVID to antigens from SARS-CoV-2 and the MMR and Tdap vaccines. They also leveraged a large, well-annotated cohort of COVID patients and found that prior MMR or Tdap vaccination was associated with decreased disease severity. Their results are published in Med.

“Our Cleveland Clinic colleagues observed an association where individuals with COVID who had either MMR or Tdap vaccines had a much lower frequency of going to the intensive care unit or dying,” said co-author Andrew Lichtman, MD, PhD, an immunologist and senior investigator in the Brigham’s Department of Pathology and professor of Pathology at Harvard Medical School. “Although previous smaller studies suggested a similar link, our in-depth epidemiological analyses, together with our basic research results, suggest that these commonly given vaccines may protect against severe disease.”

“During the COVID pandemic, we know that there was a marked decline in routine vaccinations for children and adolescents,” said corresponding author Tanya Mayadas, PhD, a senior scientist in the Brigham’s Department of Pathology and professor of Pathology at Harvard Medical School. “Our findings emphasise the importance of routine vaccination for children and adults. We know vaccines protect against devastating diseases, and we’re now seeing growing evidence that some of them provide a degree of protection against severe COVID disease.”

An unexpected observation jumpstarted the investigation. Prof Mayadas, her postdoctoral fellow Vijaya Mysore, PhD, and colleagues noted in lab experiments with COVID convalescent blood that whenever they observed a heightened T cell response to SARS-CoV-2 proteins, they also saw a heightened response to proteins from MMR and Tdap, which were controls. This was seen in both COVID convalescent and uninfected individuals vaccinated against SARS-CoV-2.

In a subsequent analysis, Prof Mayadas and colleagues teamed up with researchers at Cleveland Clinic to examine the epidemiological evidence. The Cleveland Clinic team performed a retrospective cohort study using data from more than 75 000 patients seen at the Cleveland Clinic Health System in Ohio or Florida who had tested positive for COVID between March 8, 2020, and March 31, 2021. A statistical analysis found that patients who had previously been vaccinated for MMR had a 38 percent decrease in hospitalisation and a 32 percent decrease in ICU admission/death. Patients previously vaccinated for Tdap had 23 percent and 20 percent decreased rates, for these outcomes, respectively.

“Beyond learning about the potential benefits of the MMR and Tdap vaccines in the context of COVID, this study provides a blueprint for accelerating research,” said co-author Lara Jehi, MD, MHCDS, Chief Research Information Officer of the Cleveland Clinic Health System. “Biomedical hypotheses generated in the laboratory can be explored through robust clinical and epidemiological research in well-curated, real-world data such as the Cleveland Clinic COVID Registry. Knowledge learned through this collaboration is much more than the sum of our individual parts.”

The authors note that epidemiological observations strengthen their lab findings, more work is needed to find a causal association between the MMR and Tdap vaccinations and severity of COVID disease.

“With regards to COVID vaccines, our findings predict that although MMR and Tdap are not a substitute for COVID vaccines they may afford greater and more durable protection, possibly against emerging spike variants than the COVID vaccine alone,” said Prof Mayadas. “And in areas where the COVID vaccines are not available, they could protect infected individuals from developing severe disease.”

Source: Brigham and Women’s Hospital

J&J HIV Vaccine Fails in Local Trials

HIV invading a human cell
HIV invading a human cell: Credit NIH

Johnson & Johnson and its partners announced preliminary results showing their HIV vaccine trial failed to provide sufficient protection against HIV infection in a population of young women in sub-Saharan Africa.

The vaccine had a favourable safety profile with no serious adverse events.
The Phase 2b HIV vaccine clinical trial was known as the Imbokodo study (also known as HVTN 705/HPX2008), which will now be discontinued. Further analysis of the Imbokodo study is ongoing, and the study has provided enough data to progress with key immunological correlates research.

“The high incidence of HIV among young women in sub-Saharan Africa reminds us that, despite great progress made in treatment and prevention, HIV remains a major health challenge for the region,” said Professor Glenda Gray, President and Chief Executive Officer, South African Medical Research Council (SAMRC) and Imbokodo’s Protocol Chair. “This underscores the need to apply the knowledge that will be gained from this trial to continue to advance the pursuit of a global HIV vaccine.”A parallel, ongoing Phase 3 Mosaico study (HVTN 706/HPX3002) with men who have sex with men and transgender individuals in Europe and Americas will continue due to the different HIV strains that are circulating in the trial areas and the different HIV vaccine regimen.
The HIV regimen consisted of an adenovirus vector containing four mosaic immunogens (Ad26.Mos4.HIV) at four vaccination visits over one year. The Imbokodo regimen contains a soluble protein component (Clade C gp140, adjuvanted with aluminum phosphate) which is administered at vaccination visits three and four. The ongoing Phase 3 Mosaico study is testing a different investigational vaccine regimen that involves the administration of a mosaic-based mixture of soluble proteins (Clade C/Mosaic gp140) at vaccination visits three and four.

Imbokodo participants had four vaccination visits over one year, with the primary endpoint based on new HIV infections through month 24. These data found that 63 of 1109 placebo arm participants compared to 51 of 1079 vaccine arm participants. This analysis demonstrated a vaccine efficacy point estimate of 25.2% (95% confidence interval of -10.5% to 49.3%).

HIV is prevalent in Sub-Saharan Africa, where women and girls accounted for 63 percent of all new HIV infections in 2020. The study enrolled roughly 2600 young women across Malawi, Mozambique, South Africa, Zambia and Zimbabwe. Researchers ensured that any HIV-infected participants in Imbokodo were referred to high-quality HIV treatment and care services. 

Source: PR Newswire

The Promise of Plant-based Vaccines

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Recent advances in the development and testing of plant-made vaccines has rekindled interest in plant-produced pharmaceuticals, including edible drugs, for human use. Technology and manufacturing advances could boost the uptake of such therapeutics, wrote Hugues Fausther-Bovendo and Gary Kobinger in an article published in Science

Currently, therapeutic proteins such as antibodies, hormones, cytokines, and proteins in vaccines are mostly produced in bacteria or eukaryotic systems, including chicken eggs and mammalian or insect cell cultures. In 1986, scientists proposed the use of plants for the production of these proteins in what is termed ‘molecular farming’. Such a production process can be less costly and produce fewer contaminants. 

Thus far, just one therapeutic protein derived from plants for human use has been approved (in 2012, for Gaucher disease). More recently in 2019, a plant-produced influenza virus vaccine completed phase III clinical trials with promising results, and phase III trials for a plant-made vaccine COVID vaccine started in early 2021. Plant-produced proteins have a number of advantages for vaccine development, according to Fausther-Bovendo and Kobinger, in particular the strong immune response the plant components of virus-like particles in vaccines can generate, which may reduce the need for adjuvants. 

Also interesting to consider are oral, plant-made therapeutics, said Fausther-Bovendo and Kobinger. Possibly needing minimal processing, they could avoid expensive, lengthy manufacturing. 

Edible vaccines – still predominantly in the preclinical stage of development – are also currently under development, the authors note. Compared to the proof-of-concept edible vaccines first tested decades ago, which generated weak immune responses, newly developed edible plant-made vaccines are now capable of provoking stronger immune responses, thanks to improved technology. 

Because doses for therapeutics are much higher than for vaccines, investment in manufacturing infrastructure must increase to achieve large-scale manufacturing of plant therapeutic products, Fausther-Bovendo and Kobinger said.

Source: EurekAlert!

In the Immune Battle, MRSA Uses Toxins to Fight Dirty

Scanning electron micrograph of methicillin-resistant Staphylococcus aureus and a dead human neutrophil. Credit: NIAID

Researchers have uncovered a novel trick employed by the bacterium Staphylococcus aureus — MRSA uses toxins to ‘fight dirty’ and stifle the immune response. This finding is a step towards one day producing a vaccine against MRSA.

Every year, there are some 700 000 deaths due to the emerging global threat of antimicrobial resistance (AMR). Turning the tables against AMR requires immediate action, and the development of novel vaccines to prevent such infections in the first place, are an attractive and potentially very effective option.

Staphylococcus aureus is the causative agent of the infamous MRSA ‘superbug’, one of the chief concerns of AMR. Immunologists from Trinity College Dublin, working with scientists at GSK, discovered the deadly bacteria’s new trick to foil the immune system. They found that the bacterium interferes with the host immune response by causing toxic effects on white blood cells, preventing them from carrying out their infection-fighting jobs.

The study also showed that the toxicity could be lessened following vaccination with a mutated version of a protein specifically engineered to throw a spanner in the MRSA works. This could one day lead to a vaccine for humans.

Rachel McLoughlin, Professor in Immunology in Trinity’s School of Biochemistry and Immunology and the Trinity Biomedical Sciences Institute (TBSI), said: “As a society we are witnessing first-hand the powerful impact that vaccination can have on curbing the spread of infection. However, in the backdrop of the COVID epidemic we must not lose sight of the fact that we are also waging war on a more subtle epidemic of antimicrobial resistant infection, which is potentially equally deadly.

“In this study we have identified a mechanism by which a protein made by the bacterium – known as Staphylococcal Protein A (SpA) – attacks and rapidly kills white blood cells. This protein has been widely studied for its immune evasion capacity and has a well-documented role in rendering antibodies raised against the bacterium non-functional.

“Here we uncover a previously undocumented strategy by which SpA forms immune complexes through its interaction with host antibodies, that in turn exert toxic effects on multiple white blood cell types. This discovery highlights how important it will be for effective vaccines to be capable of disarming the effects of protein A.”

Dr Fabio Bagnoli, Director, Research & Development Project Leader, GSK, said: “Our collaboration with Trinity College Dublin and in particular with Professor Rachel McLoughlin, a worldwide recognised expert on staphylococcal immunology, is critical for increasing our knowledge on protective mechanisms against S. aureus.”

The study documents the latest discovery made by this group at Trinity under an ongoing research agreement with GSK Vaccines (Siena, Italy). Overall, this collaboration aims to increase understanding of the immunology of Staphylococcus aureus infection to advance development of next-generation vaccines to prevent MRSA infections.

Source: Trinity College Dublin

Journal information: Fox, P. G., et al. (2021) Staphylococcal Protein A Induces Leukocyte Necrosis by Complexing with Human Immunoglobulins. Scientific Reports. doi.org/10.1128/mBio.00899-21.

Low Leptin Levels Can Stifle Response to Vaccines

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Reduced levels of leptin, a metabolic hormone, is linked to poor vaccine antibody responses in the general population, according to research by the University of Queensland.

The researchers made the discovery while investigating the response of several cohorts to the influenza vaccine or hepatitis B vaccine prior to COVID.

Professor Di Yu at the University of Queensland identified a link between the metabolic and immune systems that could be exploited to develop new strategies for improving vaccine protection in vulnerable populations.

“Using multiple advanced techniques in immunology, genetics and biochemistry, our study found leptin directly promoted the development and function of cells which are vital in triggering an antibody response,” Professor Yu said.

“In collaboration with global teams, we identified the reduction of an essential metabolic hormone called leptin was associated with compromised vaccine responses in both young and older individuals.

“As a result, we can now identify those who are at risk of not generating an antibody response after vaccination.”

Leptin is a metabolic hormone mostly produced by fat tissue.

“Vaccines have been known for a very long time to have a different efficacy for individuals,” he said.

“Although our genetics partially contribute to the difference, other factors are also essential. When we are fit and healthy, we have a much better vaccine efficacy.

“If we are healthy, we have a good metabolism and a normal level of leptin, but if we have malnutrition or some disease conditions, we may have a low level of leptin, which may limit our vaccine response and immune protection.”

Professor Yu said that one subject was future research was that many people with obesity and high levels of leptin conversely often had leptin resistance, which could also potentially lead to a poorer vaccine response.

The researchers are hoping to test responses to the COVID vaccines to find biomarkers that could identify people who may not mount a strong vaccine response.

“During the era of the COVID pandemic, the successful vaccination for SARS-CoV-2 is the major hope to bring society back to normalcy. Differing vaccine responses cause a major bottleneck in large-scale vaccination programs,” said Professor Yu.

Source: News-Medical.Net

.Journal information: Deng. J., et al. (2021) The metabolic hormone leptin promotes the function of TFH cells and supports vaccine responses. Nature Communications. doi.org/10.1038/s41467-021-23220-x.