By Alistair SmoutLONDON Inhaled versions of COVID-19 vaccine candidates developed by Oxford University and Imperial College will be trialled to se..
British researchers will start trial for inhaled versions of COVID-19 vaccine candidates developed by Oxford University and Imperial College to see if they deliver a localised immune response in the respiratory tract. The researchers believe that flu vaccine shots will work better if delivered by nasal spray.
Currently, the Oxford and Imperial vaccines are both being tested in trials through intramuscular injection.
However, scientists from Imperial said that vaccines delivered via inhalation could potentially deliver a more specialised response.
There was evidence that flu vaccines delivered by nasal spray could protect against and reduce transmission of the disease, said Chris Chiu of Imperial’s Department of Infectious Disease.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
"We are keen to explore if this may also be the case for SARS-CoV-2 and whether delivering COVID-19 vaccines to the respiratory tract is safe and produces an effective immune response," he said in a statement.
Trials of the Oxford vaccine, which has been licensed to AstraZeneca, resumed at the weekend after safety watchdogs gave it the go-ahead. Late-stage trials had been paused after the study subject fell in Britain.
"We have already shown that (Oxford vaccine) ChAdOx1 nCoV-19 (AZD1222) is safe and induces strong immune responses after intramuscular injection," said Sarah Gilbert of the University of Oxford.
"Delivering the vaccine to the respiratory tract instead may be a good approach to inducing immune responses in the best place to enable a rapid response after exposure to airborne virus."
Imperial’s vaccine is also in clinical trials, although at an earlier stage.
The new trials of the vaccines will see volunteers receive aerosolised vaccines through a nebulizer, delivering the vaccine as airborne droplets through a mouthpiece. A total of 30 people will be recruited to the trials.
Previous studies suggest that lower doses might be required than in intramuscular injections to give protection, the Imperial researchers said.Follow our full coverage on COVID-19 here.