A Vaccination Is On The Way

23. January 2018
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Hardly anything has influenced medicine as much as the possibility of getting vaccinated against diseases. At the moment, novel vaccines are being developed for psoriasis, allergy to cats, Alzheimer's and cancer – and that seems to be just the beginning.

It’s better not to get an illness in the first place than to fight it while it’s there. That’s why one gets vaccinated wherever it’s possible. The possible range of application is getting increasingly broader. An example of this is cat allergy.

A recent study shows that parts of the cucumber mosaic virus, which widely occurs in horticulture, can protect people from a cat allergy. Scientists from the Universities of Dundee and Oxford report on a somewhat odd new vaccine that they created from the common tetanus vaccine and a plant virus.

Cat allergy, psoriasis, Alzheimer’s

The British immunologists have also made use of the protein shell of the non-human pathogenic cucumber mosaic virus. “The cucumber mosaic virus has a particularly stable protein shell that retains its shape even when foreign protein pieces are inserted. This is not the case with many other viruses”, according to John Foerster from Dundee University. The foreign piece of protein is a protein from the tetanus vaccine. This enhances the response rate to the new vaccine since it also activates the T cells that already respond to tetanus.

“The new vaccine improves the stability of the immune response in all people who are already vaccinated against tetanus – and that means the vast majority. This is necessary because not all people produce enough antibodies after vaccination to be protected from the disease in question”, Foerster says. The range of fields of application is diverse: the new mixture is supposed to work against psoriasis, allergies and possibly even against Alzheimer.

“The idea behind it is quite simple”, says Foerster. “For diseases like psoriasis or eczema antibodies are currently the most effective agents on the market”. In chronic diseases, these antibodies are made against a particular endogenous protein. “If we block this one protein, things are much better for those affected”, Foerster adds further. When being – vaccinated against psoriasis, interleukin 17 is also added to the new vaccine made from a viral envelope and tetanus protein. Interleukin 17 is associated with various autoimmune diseases, including psoriasis.

The new vaccine also stimulates the body to produce antibodies to interleukin 17 itself. This has already been achieved in animal experiments. Should the system work in humans, in the future frequent and costly antibody injections could quickly be a thing of the past. The vaccine has worked in animal experiments against cat allergies as well. The researchers have already acquired an approval for a phase I study in humans.

In principle, this new scheme vaccination could also be used in the prevention against or treatment of Alzheimer’s disease. In Alzheimer’s disease, the beta-amyloid protein causes great damage in the brain. The injection of antibodies in test trials have scarcely achieved success. The new approach could prevent the onset of the disease by stimulating the body to produce antibodies before its symptoms break out.

Universal ‘flu vaccine

In the near future, a ‘flu vaccine with improved efficacy in the elderly might also exist. As we grow older, the human immune system changes. Because of this, the currently available ‘flu vaccines only work in one-third of the elderly over 65, experts explain. The new vaccine is said to protect more effectively than conventional vaccine due to having a different mechanism of action. The conventional vaccine utilises surface proteins of the virus in order to stimulate the human immune system to produce antibodies. However, since the virus structure is constantly changing, the vaccine needs to be updated time and again. This is done on the basis of scientific forecasts. If the viral structure changes again after the preparation of the vaccine, protection is gone.

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Until now, the pinhead-type surface proteins have been used for ‘flu vaccines. New approaches target the universal envelope protein © Pixabay

This dilemma should be able to be solved in the future: the new vaccine is based on the envelope proteins of the virus, not on the pinhead-like surface-distributed proteins as previously. In the influenza A virus at least these protein structures remain unchanged. Although humans can also become infected with influenza B viruses, infections with influenza A are those responsible for the majority of serious illnesses and deaths.

The new vaccine stimulates the formation of influenza-specific T-cells, not the production of antibodies. These T-cells are able to kill the virus as soon as it seeks to spread in the body. As a rule, every adult already carries such influenza-specific T-cells. However, their number is usually insufficient to safely protect against influenza infection. The vaccine development was preceded by studies that showed that these T-cells can fight more than just one type of influenza virus. The researchers concluded that the new vaccine is likely to protect more people and mitigate the severity and duration of influenza. The vaccine has already passed a safety check involving 145 people. During this winter its effectiveness is supposed to be tested in England on volunteers.

Vaccination against cancer?

What’s more, customised cancer vaccines are also in development. At the beginning of the year Nature presented a novel therapeutic approach to treating malignant melanoma. Patients with advanced malignant melanoma received up to eight individually compiled mRNA injections in the lymph node after the nature of the melanoma mutations had been determined. For each patient, several specific tumour antigens were selected. Making use of the matching mRNA, the patient’s immune system is supposed to be ‘made aware’ of how to respond to these neo-epitopes. The approach has worked for most patients – no side effects have been reported. This could also be due to the fact that RNA is degraded by the body after some time.

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Illustrations of the ABCDE rule. left: melanoma. right: liver spots and moles. (A) asymmetry, (B) irregular or fuzzy boundary, (C) differing pigmentation, multicoloured (D), diameter increase and greater than 5 mm. Stevenfruitsmaak – National Cancer Institute via Skin Cancer Foundation, Wikimedia Commons

“We use RNA as a messenger to insert individual tumour antigens directly into the dendritic cells”, participating physician Ugur Sahin told the German newspaper FAZ (Frankfurter Allgemeine Zeitung). Dendritic cells present antigens to other immune cells and so stimulate an immune response. “Our RNA mimics viruses and thus causes a powerful immune response, whereas the immune system otherwise has little interest in cancer cells”, Sahin says.

Every mRNA in this therapy is tailored to the needs of the patient. The number of antigens involved in a tumour is varied – from very few to several 100 mutations – everything is possible. Cancer cells can also change. Sahin is confident that all these difficulties can be overcome in the future: “At some point, it will be normal to sequence cancer cells, so as to adjust treatment much as we do today using blood counts”, he told FAZ. Today it still takes an average of 68 days before an individualised melanoma medication has been produced for a patient.

In Tübingen (Germany) one young biotech company is already working to shorten this process to a few weeks. The intention is that this service will also be extended to include breast, head and neck tumours. Following the approval of the first good cancer vaccine, an expression of interest in the new technology would nonetheless need to come from big pharmaceutical companies. This is because only they have the necessary financial means to advance the technology on a large scale.

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Image copyright: Aki Hänninen, flickr / Licence: CC BY-NC-SA
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1 comment:

Christian KOK
Christian KOK

The very best option is CBD ! and all that pharmaceutical stuff in the waste bin!

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