Oxford Covid Vaccine is Safe for the Elderly and Elicits an Immune Response, Phase 2 Study Finds | Vaccine

The article was published on Thursday (19) in the scientific journal “The Lancet”.

Phase 2 of testing a vaccine checks security and the ability to generate a response from the defense system. It is usually done with hundreds of volunteers.

Study co-author Maheshi Ramasamy said the result in the elderly is encouraging. “The robust antibody and T cell responses seen in older people in our study are encouraging. We hope this means that our vaccine will help protect some of the most vulnerable people in societybut more research is needed before we can be sure. ”

• The phase 2 study was conducted in the UK and involved 560 healthy adults – 160 between 18 and 55 years old, 160 between 56 and 69 years old and 240 over 70 years.
• The results show that the vaccine is better tolerated in older people compared to younger adults.
• The vaccine produces a similar immune response in the elderly and young adults.
• Adverse reactions were mild. The most frequent were: pain at the injection site, fatigue, headache, fever and muscle aches.
• Adverse effects were less common in the elderly than in younger adults.

Safety and immune response

In the study, the 560 healthy participants were divided into 10 groups where they received either the low-dose or standard-dose vaccine, or a meningitis vaccine (the control group). Participants older than 55 years were also divided into groups and received a single dose of the vaccine or two doses of 28 day break.

The main objective was to evaluate vaccine safety and immune response, especially in the elderly. According to the researchers, adverse reactions such as headache, muscle pain, fever, were more common in adults under 55 years of age. That is, the Oxford vaccine appears to be better tolerated in people over 56 years of age.

Regarding the immune response, the study noted that it was similar in all age groups after the second dose. “Antibody responses were induced in all age groups and were boosted and maintained 28 days after the booster vaccination, including the age group 70 years and older,” the paper says.

The researchers pointed to the lack of more volunteers over the age of 80 and the exclusion of people with chronic diseases as limitations of the study.

The Oxford vaccine is currently in the third and final phase of testing in England, India, Brazil, South Africa and the United States. In September, AstraZeneca stopped global testing of the vaccine to investigate a participant who developed a form of inflammation called transverse myelitis. In October, a Brazilian volunteer who participated in the vaccine trials died of Covid-19. The participant, however, did not receive the vaccine that was being tested, but a placebo (an inactive substance). Nowadays, the trial is in progress.

In Brazil, three other vaccines are also being tested in phase 3 of the clinical trials: Pfizer / BioNTech, Sinovac (CoronaVac) and Johnson & Johnson.

On Tuesday, the National Health Surveillance Agency (Anvisa) approved measures that should speed up the registration of vaccines against Covid-19 in the country. The standard allows companies interested in registering a vaccine to submit technical data about the tests on a continuous basis.

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.

• STAGES: Why Phase 3 Clinical Trials Are Essential to Vaccine Safety and Success

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.

Before testing in humans, vaccines are tested in animals, usually mice and then monkeys.

Watch VIDEOS about the Covid-19 vaccine race