Oxford Announces Vaccine-Induced “Strong Immune Responses” in Elderly Volunteers in Phase 2 Trials | Vaccine

The vaccine was tested in the elderly aged 56 to 69 years and in a second group, older than 70 years. The preliminary results of the tests were discussed by researcher Andrew Pollard, one of the study coordinators at the university, at a conference. As of July, the university had already reported results on younger volunteers, ages 18 to 55.

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The second stage of testing verifies the safety and ability of the vaccine to generate a response from the defense system. It is usually done with hundreds of volunteers. Phase 1 is done in dozens of people and phase 3 in thousands (see details further down in this article).

AstraZeneca said the result was “encouraging.” The Oxford vaccine is one of four undergoing phase 3 testing in Brazil – the last step before it can be released for general use.

“It is encouraging to see that immunogenicity responses were similar between older and younger adults and that reactogenicity [geração de efeitos adversos] it was lower in older adults, where the severity of Covid-19 is higher, “said a spokesman for the laboratory.

The immune response was seen “on both parts of the immune system”, according to Oxford.

The vaccines in tests against Covid-19 have sought to stimulate two responses of the defense system: one is the generation of antibodies that neutralize the new coronavirus (Sars-CoV-2) and the other is the response of the cellular immune system, which involves the called T cells.

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According to Oxford, ongoing trials will provide more data on the vaccine, but the initial result “represents an important milestone and assures us that the vaccine is safe to use and induces strong immune responses in both parts of the immune system.” in all adult groups. ”

How the 3 phases work

When testing a vaccine, usually divided into phases 1, 2 and 3, scientists try to identify serious adverse effects and whether the immunization was able to induce an immune response, that is, a response from the body’s defense system.

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Phase 1 trials generally involve dozens of volunteers; those of phase 2, hundreds; and phase 3, thousands. These phases are generally carried out separately, but due to the urgency of finding a Covid-19 vaccine, several companies have taken more than one step at the same time.