Phase 2 trials of the Oxford University COVID-19 vaccine in healthy older adults is safe and elicits an immune response.
The university confirmed that the candidate vaccine it is developing with AstraZeneca showed similar safety and immunogenicity results in healthy older people (56 years of age and older) to those seen in adults 18 to 55 years of age.
Older people are at a disproportionate risk for the COVID-19 disease more severely, so it is essential that any vaccine adopted for their use is effective in this group.
The initial stage results, which they described as “promising” were published Thursday in the medical journal The Lancet.
The phase 2 trial, involving 560 adults, including 240 over the age of 70, concluded that the vaccine causes few side effects and induces immune responses in both parts of the immune system in all age groups.
The results showed that within 14 days of the first dose of the vaccine it elicited a T cell response – it could find and attack cells infected with the virus – and caused an antibody response within 28 days of the injection. reinforcement.
Phase 3 trials, involving thousands of people, are ongoing to confirm these results, as well as the efficacy of the vaccine in protecting against infection by SARS-CoV-2 (the strain of virus that causes coronavirus disease) in a broader range of people, including older adults with underlying health problems, according to the vaccine’s developers.
“Immune responses to vaccines tend to decline in older adults because the immune system gradually deteriorates with age, which also leaves older adults more susceptible to infections,” said study lead author Professor Andrew Pollard from the University of Oxford.
“As a result, it is crucial that COVID-19 vaccines are tested in this group which is also a priority group for immunization.”
The results of the advanced phase trials will show if the Astra-Oxford vaccine can meet the standard set by the leaders Pfizer-BioNTech and Moderna.
Pfizer and BioNTech said Wednesday that the coronavirus vaccine they were developing has shown an efficacy of 95% overall, with an efficacy in adults over 65 years of age of 94%.
Pharmaceutical organizations in the US and Germany said the candidate now meets the necessary security criteria for emergency authorization.
American biotech company Moderna said on Monday that based on preliminary data, its potential coronavirus vaccine has been deemed 94.5% effective in preventing people from catching the virus.
Trials for the Astra-Oxford vaccine candidate were halted in September after one participant fell ill.
They were resumed again after the company investigated whether a vaccine recipient’s “potentially unexplained” illness was the result of receiving the vaccine.
In large trials like this one, “some participants are expected to become ill and each case must be carefully evaluated to ensure a careful assessment of safety,” said the University of Oxford.
It did not disclose medical information about the illness that caused the trial to stop, citing the confidentiality of the participants.
Health experts, including UK Government Chief Scientific Adviser Sir Patrick Vallance, have said pauses in drug trials are common to ensure safety and efficacy.