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* Inhaled vaccines could give localised response
* Oxford and Imperial vaccines are currently injected
* Aerosol vaccines might need lower doses
By Alistair Smout
LONDON, Sept 14 (Reuters) - Inhaled versions of COVID-19
vaccine candidates developed by Oxford University and Imperial
College will be trialled to see if they deliver a localised
immune response in the respiratory tract, British researchers
said on Monday.
The Oxford and Imperial vaccines are both being tested in
trials through intramuscular injection, but scientists from
Imperial said that vaccines delivered via inhalation could
potentially deliver a more specialised response.
Chris Chiu, of Imperial's Department of Infectious Disease,
said there was evidence that flu vaccines delivered by nasal
spray could protect against and reduce transmission of the
disease.
"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 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.
(Reporting by Alistair Smout; Editing by Hugh Lawson)
