The vaccine produced fewer side-effects (like temporary fatigue) in the older age group, and blood samples proved it prompted a powerful immune response.
A phase 2 clinical trial has found AstraZeneca's COVID-19 vaccine delivers similar immune responses in people aged over and under 70 years. Phase 3 is now underway in Indonesia, Brazil and Turkey.
And, crucially, the researchers wanted to know if it might work in older people who are most at risk of severe Covid.
Drugmakers of two rival vaccine candidates - one from Pfizer Inc. and Germany's BioNTech SE and another from Moderna Inc. - have each disclosed efficacy rates of more than 90%, higher than many had expected from vaccines developed so quickly.More news: Bombshell interview of Princess Diana on her troubled marriage to be probed
They found the Sinovac vaccine did create an antibody immune response, but at lower levels than those found in people who recovered from the coronavirus. The Sputnik V data from Russian Federation is even more encouraging for Oxford because, like their technology, the vaccine uses a harmless adenovirus to shuttle Covid antigens into the body, proving the approach works in principle.
Furthermore, the vaccine was less likely to cause local reactions at the injection site and symptoms on the day of vaccination in older adults than in the younger group., demonstrating that assessment of the efficacy of the vaccine is warranted in all age groups.
Between the phase 1 and phase 2 trials, the researchers changed the manufacturing process of the vaccine to increase production capacity.
"The study includes only healthy participants and not those with co-morbidities or who are frail", the Lancet reports. Most were white nonsmokers.More news: Apple to Pay $113 Million to Resolve Claims Over iPhone Battery
She notes that while today's results are a definite step in the right direction, further evidence is needed before any concrete judgement can be made on their vaccine candidate. "They must also be safe, effective in preventing disease and/or transmission, and provide at least six months of protection for people frequently exposed to the virus - such as healthcare workers". The updates go some way toward quelling fears that vaccines will fail the population that most needs protecting from SARS-CoV-2. All that has heightened anticipation of clinical results for the AstraZeneca vaccine, with hopes it can complement rollouts of other shots in parts of the world that might not have immediate access to Pfizer's and Moderna's shots.
They show that older adults aged 56-69 and over 70 had a similar immune response to younger adults aged 18-55. "It is essential that a COVID-19 vaccine can be effective across a broad age range particularly in older individuals where they are disproportionately at risk of COVID-19 disease".
Although Sinovac is still at an earlier stage, Chinese researchers say their vaccine has the advantage that it can be stored at normal fridge temperatures of 2 to 8 degrees Celsius and may remain stable for up to three years.More news: Israel Launches Retaliatory Airstrikes in Syria