Oxford-AstraZeneca COVID vaccine: Trial results kindle hope; how far we are still from a vaccine?

As many as 23 potential COVID-19 vaccines are in the human trial stage, according to data from the World Health Organization.

Oxford Covid19 vaccine: Results of early human trials of a potential COVDI-19 vaccine candidate jointly developed by the University of Oxford and pharma major AstraZeneca found the vaccine to be “safe” and without major side-effects. The results published on Monday came almost a week after US biotech firm Moderna, the first firm to begin human trials for a COVID-19 vaccine, released its own early trial data. Several pharmaceutical companies, scientists, researchers and healthcare experts are working around the clock to develop a vaccine for the coronavirus. Globally, as many as 600,000 people have died so far because of the complications linked to COVID-19.

The findings from the phase I/II trials of the Oxford- AstraZeneca vaccine in the UK, which was published in The Lancet, showed that not only the vaccine was safe, but also seemed to build an immune response in volunteers participated in the human trials. The study found the potential COVID-19 vaccine from Oxford- AstraZeneca helped develop neutralising antibodies in volunteers participated in the trials. It also increased the number of T cells— a type of white blood cell that protects the body from pathogens and cancer cells and works to actively destroy infected cells.

How does the Oxford-AstraZeneca vaccine work?

The vaccine from Oxford-AstraZeneca helps the patient develop immunity against “spike protein”. Spike protein allows the COVID-19 virus, SARS-CoV-2, to penetrate cells and multiply. The vaccine is developed on the idea is to create antibodies to fight this spiked surface without giving the virus a chance to penetrate the cells. The immune system of the patient’s body is expected to recognise the spike protein as a harmful foreign substance and starts developing antibodies against it. Once immunity is built in the patient’s body, the antibodies will attack the real virus.

According to the preliminary results from the trails, a single dose of the Oxford-AstraZeneca vaccine can develop antibodies specifically against the spike protein by the first 28 days. The trials found neutralising antibody responses in 32 of 35 participants studied after a single dose, and in all nine participants assessed after they were administered a second, booster dose.

However, the potential vaccine showed mild to moderate adverse impacts, including pain, feverish feelings, chills, muscle aches, headaches and malaise, which can be reduced by using prophylactic paracetamol, said the study.

Though the results look promising, these were only findings from phase I and phase II human trials conducted at five sites in the UK, and involving 1,077 healthy, adult participants; where 543 volunteers were administered the Oxford-AstraZeneca COVID-19 vaccine candidate—ChAdOx1 nCoV-19.

There is still no clarity on how long the antibodies will last in the body, which is an important factor in determining how effective the vaccine will be. It requires data from larger, phase III trials, which are currently underway.

The phase III of the trial has already begun in Brazil, with nearly 5,000 volunteers are participating in it. According to reports, a similar trial has been underway in South Africa.

Serum Institute of India, which has partnered with Oxford and AstraZeneca in the development of a COVID-19 vaccine, said it will apply for a trial licence soon. “We will be applying for the licensure trials to the Indian regulator in a week’s time. As soon as they grant us permission, we will begin with the trials for the vaccine in India,” said Adar Poonawalla, CEO of Serum Institute, as reported by The Indian Express.

According to a government official, Serum, so far, has received permission to manufacture certain doses for testing purposes. Serum to conduct phase III trials in India before it launches the vaccine. It plans to make “millions of doses” of the vaccine over the next three months, once it gets a manufacturing licence.

Along with US biotech firm Moderna, currently, there are more than 160 potential vaccines are being studied globally; as many as 23 from these are in the human trial stage, according to data from the World Health Organization.