AstraZeneca vaccine, with immune response in older people

The vaccine against el covid-19 developed by AstraZeneca and the Oxford University elicits an immune response between old people, especially vulnerable to the virus, according to data released Thursday confirming what was advanced in October.

However, these intermediate results correspond to a less advanced development phase (called phase 2) than those announced in recent days by the manufacturers BioNTech / Pfizer and Moderna.

The latter assured that their vaccine is effective in 95% and 94.5%, respectively, based on results from the third and final phase of their clinical trials.

The findings of phase 2 of the AstraZeneca and Oxford project were published Thursday by the medical journal The Lancet.

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The vaccine elicits an immune response in people over 56 years of age that is identical to that elicited in younger people (18-55 years).

As The Lancet recalls, “the elderly have a higher risk of developing a severe form of covid-19 and it is therefore essential that a vaccine intended to fight this disease is effective for this population group.”

“The immune response elicited by vaccines is usually less strong in the elderly as the immune system gradually weakens over time,” explains Dr. Andrew Pollard, one of the leaders of the Oxford University trial.

The researchers admit, however, that their study has its limits since the mean age of the oldest group of participants was 73-74 years and few had health problems.

“Therefore, they may not be representative of the older population as a whole, such as those who live in residences or are over 80 years old,” according to The Lancet.

The results should be “confirmed within a larger sample of volunteers, including older people with health problems.” This is the goal of the phase 3 trial, already underway, with thousands of people.

Phase 2 involved 560 participants (160 aged 18-55 years, 160 aged 56-59 years, and 240 over 70).

For its part, the Pfizer / BioNTech alliance assured on Wednesday that its own vaccine is effective among those over 65, according to phase three results, which has yet to be confirmed by its publication in a scientific journal.