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Brazilian pediatrician Monica Levi, one of the volunteers who received the COVID-19 vaccine, works at the Specialized Clinic for Infectious and Parasitic Diseases and Immunizations (CEDIPI), in Sao Paulo, Brazil, on July 24, 2020. The doctor is one of the 5,000 volunteers who participated in Brazil in phase 3 trials, the last one before homologation, of the ChAdOx1 nCoV-19 vaccine, developed by the University of Oxford together with the British pharmaceutical company AstraZeneca.
Nelson Almeida | AFP | fake images
LONDON – Preliminary findings from a phase two trial show that the coronavirus vaccine being developed by the University of Oxford and AstraZeneca is safe and triggers a similar immune response among all adults.
The promising initial results were published in The Lancet, one of the world’s leading medical journals, on Thursday.
The study of 560 healthy adults, including 240 over the age of 70, found the vaccine to be safe and produced a similar immune response among people over 56 and those aged 18 to 55.
British pharmaceutical giant AstraZeneca, working in collaboration with the University of Oxford, has previously said that interim data showed that its experimental vaccine had elicited an immune response in older and younger adults.
Many see a safe and effective vaccine as a game changer in the battle against the coronavirus pandemic, which has claimed the lives of more than 1.3 million people around the world.
However, huge challenges remain before a vaccine can be implemented. The global battle to secure potential supplies has raised the alarm about equitable access, while questions remain about logistics, distribution and cost.
The Oxford vaccine candidate was found to cause few side effects and elicit immune responses in both parts of the immune system in all age groups and at low and standard doses.
Preliminary results showed that the vaccine, ChAdOx1 nCoV-19, elicited what is known as a “T cell response” within 14 days after the first dose, and an antibody response within 28 days after the first dose. booster dose. Scientists hope that T-cell responses play a role in long-term immunity against the virus.
Dr Maheshi Ramasamy, a co-author of the study at the University of Oxford, said antibody and T-cell responses among older adults were “strong” and “encouraging.”
“Populations most at risk of severe illness from COVID-19 include people with existing health problems and older adults,” Ramasamy said.
“We hope this means that our vaccine helps protect some of the most vulnerable people in society, but more research will be needed before we can be sure.”
Study limitations
The Oxford study authors said their results could be encouraging if immune responses are found to be associated with protection against Covid-19 infection. However, the phase two trial did not assess the efficacy of the vaccine, and phase three trials are ongoing to confirm this.
Results are expected later this year depending on the infection rate within clinical trial communities.
The authors noted some limitations in their study, including that participants in the oldest age group had an average age of 73 to 74 years with few underlying health conditions, and almost all participants were white and non-smokers.
It was said that the phase three trial included people of diverse origins, countries and ethnicities.
The study comes days after two other vaccine manufacturers announced encouraging results from phase three trials. They said their experimental vaccines were found to be highly effective in protecting against coronavirus, raising optimism at a time when healthcare systems in Europe and the US are once again pushed to breaking point.
Pfizer and BioNTech said Wednesday that a final analysis found that their vaccine candidate was 95% effective in preventing Covid-19 and appeared to fight off a serious illness. Earlier this week, Moderna had said that preliminary data from the phase three trial showed its vaccine was 94.5% effective.
