Oxford University COVID-19 vaccine ‘encouraging’ for older age groups

  coronavirus vaccine developed by teams at University of Oxford has been shown to trigger a robust immune response in healthy ults d 56-69 and those over 70 years of .

findings published in ‘Lancet’ on Thursday based on 560 healthy ult volunteers shows that ChOx1 nCoV-19 vaccine is “safe and well tolerated” with a lower reactogenicity profile in older ults than in younger ults, meaning older groups could build immunity to disease.

“se findings are encouraging because older individuals are at disproportionate risk of severe COVID-19 and so any vaccine opted for use against SARS-CoV-2 [COVID-19] must be effective in older ults,” researchers te.

team is also testing wher vaccine stops people developing COVID-19 in larger Phase 3 trials and early results from this crucial st are expected in coming weeks.

We were pleased to see that our vaccine was t only well tolerated in older ults, but also stimulated similar immune responses to those seen in younger volunteers, said Dr Maheshi Ramasamy, an investigator at Oxford Vaccine Group.

next step will be to see if this translates into protection from disease itself, she said.This means re are w four promising vaccines on horizon after Pfizer-BioNTech, Sputnik and Moderna alrey reporting good preliminary data from Phase 3 trials. UK has alrey ordered 100 million doses of Oxford vaccine, being manufactured by pharma major AstraZeneca. vaccine also has a tie-up with Serum Institute of India.Professor Andrew Pollard, he of Oxford's vaccine trial team, said he is "absolutely delighted" with latest results.Crucially, study also found “suspected unexpected serious verse reactions” during this st of trial. 560 healthy ult volunteers who took part in phase two trials were given two doses of vaccine candidate, or a placebo.

"Inducing robust immune responses in older ults has been a long-standing challenge in human vaccine research,” said Dr Angela Minassian, an investigator at University of Oxford and horary consultant in infectious diseases.

To show this vaccine techlogy is able to induce se responses, in group most at risk from severe COVID-19 disease, offers hope that vaccine efficacy will be similar in younger and older ults,she said.

Thursday’s report on data from Phase 2 trial of ChOx1 nCoV-19 vaccine shows that volunteers in trial demonstrate similar neutralising antibody titres, and T cell responses across all three groups - 18-55, 56-79, and 70+.

outcomes reported at this st of study include safety of vaccine and immune responses of participants in different groups following vaccination. It is important to assess how well vaccine works in older people, as se groups are more severely affected by COVID-19 disease,  study tes.

Sometimes vaccines are less effective in older people, so it is important to find out at an early st how well immune system responds to vaccine in those over of 55,it ds.

Antibodies play an important role in immune response to viruses. latest trial assessed both quantity and quality of antibody found in participant blood samples.

An ELISA (enzyme-linked immusorbent assay - a plate-based laboratory technique) was used to detect and measure quantity of antibodies in blood that recognise spike protein.

In dition to measuring quantity of antibody, study also examined quality of antibody, its ability to neutralise virus. Like previous study, good levels of neutralising antibodies were produced, and this was consistent across all groups, research team tes.

T cells play an important role in immune response to viral infections. Some T cells are responsible for killing viruses inside infected cells, whilst ors are responsible for providing help to or components of immune response.

re is increasing evidence that T cells play an important role in preventing serious disease with natural infection of COVID-19 virus.

latest trial shows that after a single vaccination, T cell responses were highly comparable in all s and across different doses.

participants in this study continue to be monitored to assess how well immune responses are maintained over a longer time period,  research team said.

To assess wher vaccine works to protect from COVID-19, statisticians in our team will compare number of infections in control group with number of infections in vaccinated group.

How quickly we reach numbers required will depend on levels of virus transmission in community.

With current low transmission levels in UK, this could take many months,y d.

researchers say y have completed recruitment of over 10,000 people to its Phase 2-3 study, which aims to assess efficacy of vaccine, and to compare different dose schedules. 

(IM CREDITS:PTI)