The Oxford University-AstraZeneca combine’s Covid-19 vaccine candidate is seen to be safe in older, healthy adults, according to early stage results published in The Lancet.

The vaccine  “shows similar safety and immunogenicity results in healthy older adults (aged 56 years and over) to those seen in adults aged 18-55 years,” a note from the journal said.

The development is of consequence to senior citizens, who are particularly vulnerable to the virus. And, it is of interest to India, as Pune-based Serum Institute has a production and distribution alliance on this vaccine for low and middle income countries.

The study comes a day after Pfizer-BioNTech said, their vaccine showed 95 percent efficacy from late stage Phase III trials, which was consistent across age, gender and race. But a spokesperson for the journal told BusinessLine, the Oxford vaccine candidate’s published details were peer-reviewed, as compared to announcements from pharma companies.

The latest study from Oxford-AZ candidate’s Phase II trials said that “the vaccine causes few side effects, and induces immune responses in both parts of the immune system in all age groups and at low and standard dose — provoking a T-cell response within 14 days of the first dose of vaccination , and an antibody response within 28 days of the booster dose of vaccination.”

Phase-III trials are ongoing to confirm these results, as well as how effective the vaccine is in protecting against Covid-19, in a broader range of people, including older adults with underlying health conditions, a note from the journal said.

Older, more susceptible

Oxford University’s Professor Andrew Pollard, lead author of the study explained, “Immune responses from vaccines are often lessened in older adults because the immune system gradually deteriorates with age, which also leaves older adults more susceptible to infections. As a result, it is crucial that Covid-19 vaccines are tested in this group who are also a priority group for immunisation.”

The new study is the fifth published clinical trial of a vaccine against SARS-CoV-2 tested in an older adult population. Other Covid-19 vaccines have also been shown to generate immune responses in older adults, but it can be difficult to compare results between different studies. One study has shown similar immune responses in young and old adults (Moderna mRNA vaccine), while other trials have suggested lower measured responses in older adults, compared to younger adults receiving the same vaccine (CanSino single dose adenovirus-vector vaccine, Pfizer/BioNTech mRNA vaccine, and SinoPharm/Beijing Institute of Biological Products inactivated viral vaccine), the note added.