Few of us like needles, but in the last year or so most of us have embraced them — celebrated dates, queued to get pricked and shared vaccination Selfies on social media.
But one day, needles and the ravages of Covid-19could go down in history.
As a result of the pandemic, vaccine research has exploded, particularly with a view to a new generation of no-jab vaccines that use different technologies to elicit stronger immune responses.
There are currently 13 nasal sprays or pills in development for Covid-19 alone, and several of these trials are ongoing in the UK.
Young children are already routinely given flu vaccines via a nasal mist, and trials have begun using nasal sprays to protect against respiratory syncytial virus, or RSV, a leading cause of potentially fatal chest infections in the very young and elderly.
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The latest results of a clinical trial of an oral vaccine against norovirus – the nausea virus notorious for turning dream cruise ship trips into nightmarish cabin lockdowns – will be released shortly.
And in the US, researchers have even developed a nasal vaccine they hope will prevent or slow Alzheimer’s by stimulating immune cells to break down sticky plaques in the brain associated with this form of dementia.
The first doses were given to patients with early dementia late last year, and Dr. Tanuja Chitnis, the scientist who led the study, says: “Research in this area has paved the way for us to embark on a whole new avenue to potentially treat not only Alzheimer’s but also other neurodegenerative diseases.”
However, in the fight against Covid-19, mucosal vaccines – as these sprays and pills are collectively called – could be a game changer, says Ultan Power, professor of molecular virology at the Wellcome Wolfson Institute for Experimental Medicine, Queen’s University Belfast.
“They will be a major player in managing the pandemic,” he says.
“The existing vaccines have been fantastic at reducing serious illness and death, but as we have seen omicrontheir ability to reduce transmission is somewhat compromised.
“Mucosa vaccines generate stronger immune responses in the airways and this has the potential to induce sterilizing immunity and stop the virus in its tracks. If we can reduce infections, we will also reduce the virus’ chances of mutating and find ways to evade the immune system.”
dr Sandy Douglas, a pharmacist at Oxford University’s Jenner Institute who worked on expanding the AstraZeneca vaccine, says: “Put simply, mucosal vaccines reach parts of the immune system that other vaccines don’t.”
He adds: “When a vaccine is injected, it ends up in the lymph nodes and produces IgG antibodies that circulate throughout the body.”
This all-purpose IgG immunity doesn’t necessarily prevent infection, but it does dramatically reduce the chance of getting seriously ill.
“When a vaccine is given nasally, it also produces IgA antibodies, which provide a strong defense against antigens, and a special type of long-lived immune system T-cells known as tissue-resident memory T-cells.
As the name suggests, they live in a specific tissue, like the lining around the airways.”
Since IgA antibodies and TRM-T cells are produced in large numbers in mucosal tissues – such as the lining of the nose, airways and intestines – they are very effective in stopping viruses and other infections.
IgG antibodies will also be present in the mucosal tissue, but not necessarily in sufficient concentration to prevent some bugs from entering the body further and causing an infection.
Professor Power believes combining traditional vaccines with nasal or oral boosters could be the ‘jackpot’ in terms of fighting Covid-19.
In fact, the team led by Dr. Douglas at the Jenner Institute has already begun clinical trials of a nasal version of the AstraZeneca vaccine, which they hope will someday provide a “super booster” ahead of cold and flu season.
The skin is our primary immune defense and is rich in immune cells designed to prevent infection when we get a cut or scrape.
Twenty years of research confirms that skin patches lined with microneedles can also deliver a broader immune response than traditional vaccines. However, their use has been limited by manufacturing challenges in loading vaccines into microneedles.
This is another area where there has been a surge in research as a result of Covid, such as: B. Printing patches with 3D printers.
Intuitively, it makes sense that an immune response activated in the nose and airways would be better at stopping infections at these sites, but oral Covid-19 vaccines have also been shown to produce turbocharged mucosal immunity – among other benefits.
Vaxart, a US-based biotech company, was working on an oral norovirus vaccine early in the pandemic and had already figured out how to protect a vaccine from stomach acid and deliver it to the lining of the gut.
This technology was adapted for Coronavirus and the results of Phase II trials of their oral Covid-19 vaccine are due any day.
Preliminary studies show that it activates IgA antibodies both in the nose and in the bloodstream, as well as a stronger T-cell response. It also reduces viral shedding and infections.
dr Sean Tucker, Vaxart’s Chief Scientific Officer, says: “By providing broader immunity, we can reduce the potential for new variants.
An oral vaccine in pill form could transform how the world is protected from Covid-19 and other infections because they are easy to distribute and administer.”
He adds, “There are great benefits to immunization programs because they don’t need to be stored in very cold temperatures and anyone can administer a pill.”
Another potential plus is the vaccination of people who are afraid of needles. Research has confirmed that despite the risks associated with contracting Covid-19, this is a barrier for one in ten people in the UK.
https://www.mirror.co.uk/lifestyle/health/nasal-sprays-pills-could-game-26726892 Nasal sprays and pills could be 'game changing' in future fight against Covid-19