Brazilian pediatrician Doctor Monica Levy, one of the volunteers receiving the COVID-19 vaccine, works at the Special Clinic for Infectious and Parasitic Diseases and Immunity (CEDIPI) in Sao Paulo, Brazil on July 24, 2020. Doctor is one of 5,000 volunteers participating in the Phase 3 trials in Brazil – the last before homologation – by the ChAdOx1 nCoV-19 vaccine, developed by the University of Oxford in association with the British pharmaceutical company AstraZeneca.
Nelson Alameda | AFP | Getty Images
LONDON – Preliminary findings from a phase two trial show that the coronavirus virus being developed by Oxford University and AstraZeneca is safe and triggers a similar immune response among all adults.
The promising early stage results were published in The Lancet, one of the world’s top medical journals, on Thursday.
A study of 560 healthy adults, including more than 240 people over the age of 70, found the vaccine to be safe and produced a similar immune response among people over 56 years of age and 18 to 55 years of age.
British pharmaceutical giant AstraZeneca, which is working closely with the University of Oxford, said earlier that interim data showed that their experimental vaccine caused an immune response in older and younger adults.
A safe and effective vaccine is viewed by many as a game-changer in the fight against the coronovirus pandemic, which has claimed the lives of more than 1.3 million people worldwide.
However, major challenges remain before a vaccine is rolled out. The global battle to secure future supplies has raised alarm about equal access, while questions on logistics, distribution and costs remain.
The Oxford vaccine candidate showed some side effects and triggered immune responses in all age groups and in both the parts of the immune system in low and standard doses.
Preliminary results showed that the vaccine – ChAdOx1 nCoV-19 – indicated what is known as a “T-cell response” within 14 days of the first dose, and an antibody response within 28 days of the booster dose. Scientists expect T-cell responses to play a role in long-term immunity against the virus.
The study co-authored at the University of Oxford, Drs. Maheshi Ramasamy said that antibodies and T-cell reactions among older adults were “strong” and “encouraging”.
“The largest population of severe COVID-19 disease includes current health conditions and older adult people,” Ramasamy said.
“We hope that this means that our vaccine will help protect some of society’s most vulnerable people, but further research will be needed before we can be sure.”
The authors of the Oxford study stated that their results could be encouraging if the immune response is found to be associated with protection from Kovid-19 infection. Phase two trials did not assess vaccine efficacy, however, and phase three trials are ongoing to confirm this.
Results are expected later this year based on the rate of infection within clinical trial communities.
The authors noted some limitations in their study, with the oldest age group of participants aged 73 to 74 and some underlying health conditions, and nearly all participants were white and non-smokers.
Phase three trials included people from backgrounds, countries, and breeds.
The study came days after two other vaccine manufacturers announced encouraging results from phase three trials. He said his experimental vaccines were found to be highly effective in protecting against coronaviruses, increasing optimism at a time when health systems in Europe and the US are once again being pushed to the breaking point.
Pfizer and BioNotech said on Wednesday that a final analysis found that their vaccine candidate was 95% effective in preventing Kovid-19 and protecting against serious illness. Earlier this week, Modern stated that three early-stage test data showed that its vaccine was 94.5% effective.