Expanding the role of bacterial vaccines into life-course vaccination strategies and prevention of antimicrobial-resistant infections
Farmers' Fury As Labour Set To End Badger Culls And Replace Them With Tuberculosis Vaccine Programme
Culling badgers to prevent tuberculosis spreading among cattle will end within five years, ministers said yesterday.
Instead of being shot in their thousands, badgers will now be vaccinated instead – a move likely to enrage farmers.
The badger cull formed a central pillar of the previous Government's efforts to reduce TB in cattle.
But the Labour administration said it would stop the cull by 2029, carry out a census of badgers and develop vaccines for badgers and cattle.
TB is often passed by close contact between infected and non-infected animals, including cattle themselves.
Former Queen guitarist and campaigner Brian May at an event planned to urge the government to abandon a badger cull planned for the autumn
Animal rights protesters outside the National Farmers Union Conference protesting about the badger cull
Instead of being shot in their thousands, badgers will now be vaccinated instead – a move likely to enrage farmers (stock photo)
More than 278,000 cattle have been compulsorily slaughtered and 230,000 badgers have been killed in efforts to control the disease since culling began in 2013. The process is thought to cost taxpayers more than £100million every year.
Tom Bradshaw, president of the National Farmers' Union said last night: 'This terrible disease continues to plague farmers and their livestock.
While significant elements of the Government's proposed TB strategy are still being researched and not yet deployable, they must not overlook the contribution of the successful disease control model. Scientific papers show that targeted badger culling provides success.'
In February, a major study found that after four years of culling 'the herd incidence rate of TB reduced by 56 per cent', prompting Countryside Alliance chief executive Tim Bonner to say: 'Put simply, culling has worked.'
However, campaigners including Queen guitarist Brian May and broadcaster Chris Packham have called for an end to the cull, which has devastated badger populations in the Midlands, the West and the South West.
Animal rights activists and environmental campaigners protests outside the Home Office against badger culls in 2019
Badger populations in the Midlands, the West and the South West have been devastated by culls
Ministers claim vaccination will create progressively healthier badger populations.
Rural affairs minister Daniel Zeichner said: 'Bovine tuberculosis has devastated farmers and wildlife for too long.
'It has placed dreadful hardship on farmers and has taken a terrible toll on our badger populations. No more.'
But Peter Hambly, of the Badger Trust, said the announcement focused 'too much on badgers rather than cattle, when cattle are the main spreaders of this cattle disease'.
He added: 'It admits the Government doesn't know how many badgers are left. They haven't counted them and haven't tested them but continue to slaughter them.'
1st District In India, 2.3k In S Goa Get Anti-TB Jab
Panaji: More than 2,300 adults in South Goa have been vaccinated with the adult BCG vaccine from Jan to Aug this year. Launched in South Goa—the first district in the country—in Jan, the adult BCG vaccination study is part of the nation's efforts to eradicate TB. It has not been launched in North Goa as the district will be used as a comparator.Although eligible persons include cured TB patients, contacts of TB patients, smokers, diabetics, malnourished individuals, and senior citizens, it is mostly contacts of TB patients, who have come forward to take the vaccine. Only 2.3% of the eligible persons—estimated at one lakh—have taken the vaccine, said state TB officer Dr Manish Gaunekar to TOI. Around 6,000 people have said they are willing to take it."Health workers are spreading awareness about the vaccine's benefits and are carrying out door to door surveys to identify beneficiaries. We cannot force anybody to take the vaccine," said Gaunekar."As of now, we have had only six minor adverse effects of local swelling," he said."Chances of developing TB reduce drastically once a person is vaccinated. Prevention is better than cure. A person who contracts TB experiences weight loss among other symptoms and cannot work efficiently. The patient's overall quality of life gets affected," he said. Goa sees more than 2,000 TB yearly cases with a death rate of around 10%, among the highest in the country. With the vaccine, Goa hopes to reduce the TB disease burden.Senior chest physician and South Goa district TB officer Dr Govind Desai says the vaccine is safe and time-tested. "Studies have shown that the overall incidence of TB in a geographical area comes down after taking it. A person may still get infected, but the vaccine will prevent the disease from flaring up and developing into a severe form," he said.Proven effective in infants, the BCG vaccine is being administered to adults for the first time. All 17 health centres in South Goa offer the vaccine free of cost on specified days of the week to the eligible population. The vaccine is not available for adults in the private setup.Immune Protection Against Tuberculosis Reinfection Driven By Cells That Dampen Lung Inflammation
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JoAnne Flynn, Ph.D.
view moreCredit: JoAnne Flynn
The body's first line of defense against tuberculosis (TB) involves immune cells that suppress lung inflammation instead of activating it, reported University of Pittsburgh and the Ragon Institute of Mass General, MIT, and Harvard scientists today in Immunity.
The research showed that a subset of infection-fighting white blood cells, called CD4 T cells, protect the lungs from reinfection by creating an anti-inflammatory environment within the lung tissue, rather than secreting molecules that directly kill invading Mycobacterium tuberculosis, or Mtb, bacteria that cause TB.
The unexpected discovery complements previous research about the role of protective immune T cells in controlling TB infection and points at ways to improve existing tuberculosis vaccines.
"Our study suggests that a vaccine that induces the 'right' kind of CD4 T cells that limit inflammation quickly upon infection may be key to providing long lasting immunity," said senior and corresponding author JoAnne Flynn, Ph.D., distinguished professor and chair of microbiology and molecular genetics at Pitt.
Despite TB being all but eradicated in the United States, an estimated 10.6 million people globally fell ill with the disease in 2022. TB remains especially prevalent and deadly in Southeast Asia, Africa and the Western Pacific, where outbreaks occur regularly and people often get exposed to Mtb multiple times, even after the initial infection was cured.
Mtb infection is often accompanied by symptoms such as persistent cough, extreme exhaustion and fever, and it can cause lung inflammation and scarring. Yet, despite its significant public health burden, the disease has not been eradicated yet – largely due to relative ineffectiveness of the existing vaccine, Bacille Calmette-Guerin (BCG), which can protect young infants but not adults.
The development of better vaccines has been limited by an imperfect understanding of the dynamic interplay between Mtb and the host's immune system and how Mtb evades immune response.
Previous infection with Mtb in humans provides some level of protection against development of tuberculosis following re-exposure. To better understand the effect of prior infection on subsequent Mtb infections, Flynn and her team turned to macaque monkeys that had been exposed to the pathogen in the past. Flynn's previous research has shown that ongoing or drug-treated tuberculosis protects against reinfection and disease. In the new study, researchers explored whether CD4 T cells are essential for such protection.
Surprisingly for Flynn, instead of observing that CD4 T lymphocytes secreted molecules that attract other infection-fighting cells to the sites of the Mtb invasion, CD4 cells instead contained the inflammation, making the infection site less hospitable to the bacteria.
Using precise molecular techniques, including single-cell RNA sequencing, the team showed that this process is mediated in part by the effects of CD4 T cells on CD8 T cells – another subset of white blood immune cells whose main function is killing cells infected by viruses. This interplay between CD4 and CD8 cells that Flynn observed by studying Mtb reinfection complements her previous research that suggested that CD8 T cells control Mtb infection by setting up an anti-inflammatory environment in the lung.
The researchers concluded that the interplay between CD4 and CD8 T cells creates an anti-inflammatory environment that is hostile to Mtb and, as a result, limits bacterial growth and disease severity.
The expanded understanding of the role of CD4 T cells in preventing tuberculosis could provide new strategies for vaccine development.
"Our work demonstrates that control of TB requires a complex and sophisticated interplay of immune factors," said Flynn. "Vaccine strategies have focused on inducing inflammatory CD4 T cells, but it might be time to shift our focus to reducing inflammation to the minimum level needed to limit growth of the bacteria, which will involve anti-inflammatory CD8 T cells and other cell types early on in infection".
Other authors of this research are Sharie Keanne Ganchua, Ph.D., Pauline Maiello, M.A., H. Jacob Borish, PhD., Mark Rodgers, M.S., Jaime Tomko, Kara Kracinovsky, Edwin Klein, D.V.M., Hannah Gideon, Ph.D., Charles Scanga, Ph.D., Philana Ling Lin, M.D., M.Sc., all of Pitt; Joshua Bromley, B.S., Sarah Nyquist, B.S., Michael Chao, Ph.D., Douaa Mugahid, M.S., Son Nguyen, Ph.D., Jacob Rosenberg, M.D., Ph.D., Roisin Floyd-O'Sullivan, B.S., Sarah Fortune, M.D., and Alex Shalek, Ph.D., of Ragon Institute of MGH, MIT, and Harvard; and Qianchang Dennis Wang, B.S., and Bonnie Berger, Ph.D., of MIT.
Article TitleCD4+ T cells re-wire granuloma cellularity and regulatory networks to promote immunomodulation following Mtb reinfection
Article Publication Date29-Aug-2024
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