Oxford coronavirus vaccine shows promise, can train immune system

The human trials of coronavirus vaccine candidate developed by the University of Oxford and backed by AstraZeneca Plc has shown positive results. The first phase of human trials of vaccine, officially known as AZD1222, have appeared to be safe and prompted a protective immune response in hundreds of people who got the shot, as per a report published in British medical journal Lancet.

According to the journal, the test was conducted on 1,077 healthy volunteers aged between 18-55 years in five UK hospitals in April and May as part of the phase one clinical trial. The results showed the vaccine candidate triggered strong antibody and T-cell immune responses in test subjects for up to 56 days after they were given the vaccine. T-cells are crucial for maintaining protection against the virus for years.

Experts see the early results as promising, but feel it is too soon to know if this is enough to offer protection as larger trials get underway. The phase two of the trials is already underway in the UK and phase three testing is taking place on volunteers in Brazil.

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"There is still much work to be done before we can confirm if our vaccine will help manage the COVID-19 pandemic, but these early results hold promise," said Professor Sarah Gilbert, co-author of the study.

"Continuing to test our vaccine in phase 3 trials, we need to learn more about the virus - for example, we still do not know how strong an immune response we need to provoke to effectively protect against SARS-CoV-2 infection. If our vaccine is effective, it is a promising option as these types of vaccine can be manufactured at large scale," she said.

Meanwhile, scientists, who conducted the trials, feel that response could be even greater after a second dose.

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"The immune responses observed following vaccination is in line with what previous animal studies have shown in association with protection against the SARS-CoV-2 virus, although we must continue with our rigorous clinical trial programme to confirm this in humans," said Professor Andrew Pollard, Chief investigator of the Oxford Vaccine Trial at Oxford University and co-author of the study.

"We saw the strongest immune response in the 10 participants who received two doses of the vaccine, indicating that this might be a good strategy for vaccination," he said.

The project has been backed by 84 million pounds of government funding to help accelerate the vaccine's development. The University of Oxford is working with UK-based global biopharmaceutical company AstraZeneca for further development, large-scale manufacture and potential distribution of the COVID-19 vaccine, with plans for clinical development and production of the Oxford vaccine progressing globally.

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Meanwhile, Pune-based Serum Institute of India (SII) has reportedly said it would start human trials for the Oxford- AstraZeneca's coronavirus vaccine candidate from next month.

Apart from Oxford coronavirus vaccine, Hyderabad-based Bharat Biotech has successfully started human trials on its vaccine candidate 'COVAXIN'. The vaccine is being developed in collaboration with the Indian Council of Medical Research (ICMR) - National Institute of Virology (NIV). The human trial of COVAXIN has started in All India Institute of Medical Sciences in Patna and Post-Graduate Institute of Medical Sciences in Rohtak.

COVAXIN, the country's first possible vaccine against COVID-19, will be tested on over 1,100 people in two phases. The company plans to enroll 375 participants to test COVID-19 vaccine candidate in the first phase of clinical trials. Based on the first trial's results, it has a plan to enroll 750 people in the second phase of trial.

By Chitranjan Kumar with PTI inputs