QualPharma December 2020

OXFORD TECHNOLOGY
CORONAVIRUS SPECIAL
The Oxford COVID-19 vaccine team is led
by Prof Sarah Gilbert, Prof Andrew Pollard,
Prof Teresa Lambe, Dr Sandy Douglas,
Prof Catherine Green and Prof Adrian
Hill. Their team includes scientists from
both the Jenner Institute and the Oxford
Vaccine Group, who bring together decades
of internationally recognised experience
in vaccine research, including responding
to the Ebola outbreak of 2014.
The teams had already used ChAdOx1
vaccine technology to produce candidate
vaccines against a number of pathogens
including flu, Zika and Middle East Respiratory
Syndrome (MERS), another
coronavirus. They had already begun
work on pandemic preparedness with the
technology behind ChAdOx, in preparation
for 'Disease X'. When the disease
emerged in China, they moved quickly. As
soon as the genetic sequence was available,
they began work on a trial.
How the Oxford COVID-19 vaccine
works
The ChAdOx1 vaccine is a chimpanzee
adenovirus vaccine vector. This is a harmless,
weakened adenovirus that usually
causes the common cold in chimpanzees.
ChAdOx1 was chosen as the most suitable
vaccine technology for a SARS-CoV-2
vaccine as it has been shown to generate a
strong immune response from one dose
in other vaccines. It has been genetically
changed so that it is impossible for it to
grow in humans. This also makes it safer
to give to children, the elderly and anyone
with a pre-existing condition such as diabetes.
Chimpanzee adenoviral vectors are
a very well-studied vaccine type, having
been used safely in thousands of subjects.
Coronaviruses have club-shaped
spikes on their outer coats, which
form a corona – Latin for crown –
on the virus surface. Immune responses
from other coronavirus
studies suggest that these spikes are
a good target for a vaccine.
The Oxford vaccine contains the genetic
sequence of this surface spike protein.
When the vaccine enters cells inside the
body, it uses this genetic code to produce
the surface spike protein of the coronavirus.
This induces an immune response,
priming the immune system to attack the
coronavirus if it later infects the body.
The Oxford COVID-19 vaccine trials
The main focus of the Phase I, II and III
studies is to assess whether the ChAdOx1
vaccine is going to work against COVID-
19, that it doesn’t cause unacceptable side
effects and if it induces good immune
responses.
Adult participants will be randomised
to receive one or two doses of
either the ChAdOx1 nCoV-19 vaccine
or a licensed vaccine
(MenACWY) that will be used as a
‘control’ for comparison.
Phase I: The phase I trial in healthy
adult volunteers began in April 2020.
More than 1,000 immunisations were
given in the UK.
Phase II: The phase II part of the
study expands the age range of people
the vaccine is assessed in, to include a
small number of older adults and children.
Researchers will be assessing
the immune response to the vaccine
in people of different ages, to find out
if there is variation in how well the
immune system responds in older
people or children. The group of children
will be recruited later in the trial,
once extensive safety data is available
from the adult studies.
Phase III: The phase III part of the
study involves assessing how the vaccine
works in a large number of people
over the age of 18. This group will
assess how well the vaccine works to
prevent people from becoming infected
and unwell with COVID-19. It
involves multiple locations, including
other countries.
Vaccine results and production
To assess whether the vaccine works to
protect from COVID-19, the statisticians
in our team will compare the number of
infections in the control group with the
number of infections in the vaccinated
group.
QualPharma *Dec 2020* , Vol.3 ISSUE 12