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. – AstraZeneca’s experimental coronavirus vaccine appears to work safely in older people, eliciting as strong an immune response in those over 70 as it does in younger people, British researchers reported Thursday.
The phase 2 trial did not show whether the vaccine protects the volunteers from infection, but it elicited an immune response that would be expected to provide protection, the researchers reported in the Lancet medical journal.
AstraZeneca, which developed its vaccine with researchers from Britain’s Oxford University, is testing its vaccine in phase 3 clinical trials around the world, the last stage before seeking regulatory approval.
Phase 2 results released Thursday involved 560 volunteers over the age of 18; 240 of them are over 70. That’s important, because older people are more likely to develop serious illness and die from infection.
“Our findings show that the ChAdOx1 nCoV-19 vaccine is safe and well tolerated,” the researchers reported in The Lancet.
‘If these responses are correlated with protection in humans, these findings are encouraging because older people are at disproportionate risk for severe COVID-19, and therefore any vaccine adopted for use against SARS-CoV-2 must be effective in older adults ».
How does it work?
ChAdOx1 is the experimental name for the vaccine. It is manufactured differently than Pfizer and Moderna vaccines. It uses a modified cold virus called adenovirus, but it is one that infects chimpanzees and does not make people sick. The virus is genetically engineered to carry a small part of the coronavirus into the body and train the immune system to recognize and attack it.
The vaccines prompted the body to make both antibodies and immune cells called T cells.
“The robust antibody and T cell responses seen in older people in our study are encouraging. Populations most at risk of severe covid-19 disease include people with existing health problems and older adults, ”said Dr Maheshi Ramasamy of the University of Oxford, who worked on the study, in a statement.
The study comes after two candidate vaccines in the US reported 95% efficacy. Pfizer says it expects to apply for emergency use authorization from the US Food and Drug Administration for its vaccine on Friday, and Moderna says it also plans to apply for authorization soon.
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