In a Cell study, an experimental intranasal vaccine created by scientists at the Washington University School of Medicine has shown to bring about an immune response in the mucosa which prevents COVID-19 infection.
Researchers have since developed an intranasal biotechnology spray which makes it difficult for the virus to attach to human cells, and when used daily it is able to block transmission of the virus.
Four intranasal vaccines have progressed to the first phase of clinical testing in the UK, the US, China and India.
In the UK, biotechnology company Codagenix will use its computer algorithm to decode the virus in the vaccine, reducing pathogenesis and consequently triggering an immune response.
WHY IT MATTERS
The research suggests that a coronavirus infection can be present in the nose even after it has left the lungs, making it possible to spread the virus even after vaccination.
Using laboratory animals, the study specifically demonstrates the role of the mucosa route in preventing infection. Intranasal vaccines have the potential to boost immune defenses in the mucosa. This then triggers production of an antibody known as immunoglobulin A, which can block infection.
Unlike an injection, a nasal spray is painless and appealing to those who have concerns or phobias about needles. Futhermore, the intranasal vaccine can be self-administered at home and some require no refrigeration, making it easier to transport and store. This is particularly important in low-resource countries.
If yearly booster vaccinations are needed for emerging coronavirus variants, the intransal spray can be sent via mail, providing easy and quick access to large portions of the population.
A NCBI report on nasal vaccines entitled, 'Current prospects and future challenges for nasal vaccine delivery' states: "Nasal delivery offers many benefits over traditional approaches to vaccine administration. These include ease of administration without needles that reduces issues associated with needlestick injuries and disposal. Additionally, this route offers easy access to a key part of the immune system that can stimulate other mucosal sites throughout the body."
"Particular focus should be brought to designing delivery strategies that take into account the broad range of diseases, populations and healthcare delivery settings that stand to benefit from this unique mucosal route."
THE LARGER CONTEXT
Recently, logistics group and vaccine distributor, Kuehne+Nagel told the Financial Times that more than half of adults in wealthy countries will still be waiting to receive a first dose of the COVID-19 vaccine in 15 months' time, while developing countries are unlikely to have vaccinated a majority of their population before 2023.
Although approximately 160 million COVID-19 vaccinations have been administered globally, there are still delays in Asian regions due to vaccine hesitancy, adopting a cautious approach and misinformation.
In the UK, approximately 18 million people in England have received at least one dose of the vaccine since 8 December.
ON THE RECORD
Helmy Yusuf and Vicky Kett, lecturers at the School of Pharmacy, Queen's University of Belfast, UK, wrote in the NCBI report: "There are several needle free methods of vaccination such as transdermal delivery and mucosal delivery. Mucosal immunisation has been successfully used in human vaccination. The human mucosal immune system is large and specialised in performing inspection for foreign antigens to protect the surfaces themselves and of course human body interior. Since most infections affect or start from mucosal surfaces, using a mucosal route of vaccination is of great interest and provides a rational reason to induce a protective immune response. Nasal delivery of vaccine offers an easily accessible route to the immune system."
