Oxford vaccine gives first ray of hope against Covid

Experimental vaccine shows immune response against Corona

London, July 20: Scientists at Oxford University say their experimental Coronavirus vaccine has been shown in an early trial to prompt a protective immune response in hundreds of people who got the shot.

British researchers first began testing the vaccine in April in about 1,000 people, half of whom got the experimental vaccine. Such early trials are usually designed only to evaluate safety, but in this case experts were also looking to see what kind of immune response was provoked.

In research published Monday in the journal Lancet, scientists said that they found their experimental Covid-19 vaccine produced a dual immune response in people aged 18 to 55. “We are seeing good immune response in almost everybody,” said Dr. Adrian Hill, director of the Jenner Institute at Oxford University.

“What this vaccine does particularly well is trigger both arms of the immune system,” he said.

Dr Hill said that neutralising antibodies have produced molecules which are key to blocking infection. In addition, the vaccine also causes a reaction in the body’s T-cells which help to fight off the Coronavirus.

The Oxford University researcher said that larger trials evaluating the vaccine’s effectiveness, involving about 10,000 people in the United Kingdom as well as participants in South Africa and Brazil are still underway. Another big trial is slated to start in the US soon, aiming to enroll about 30,000 people.

Dr Hill estimated they might have sufficient data by the end of the year to decide if the vaccine should be adopted for mass vaccination campaigns.

He said the vaccine seemed to produce a comparable level of antibodies to those produced by people who recovered from a

Covid-19 infection and hoped that the T-cell response would provide extra protection.

There’s increasing evidence that having a T-cell response as well as antibodies could be very important in controlling

Covid-19, Dr Hill said. He suggested the immune response might be boosted after a second dose; their trial tested two doses administered about four weeks apart.

Dr Hill said Oxford’s vaccine is designed to reduce disease and transmission. It uses a harmless virus a chimpanzee cold virus, engineered so it can’t spread to carry the coronavirus’ spike protein into the body, which should trigger an immune system response.

Dr Hill said Oxford has partnered with drugmaker AstraZeneca to produce their vaccine globally, and that the company has already committed to making two billion doses.

Even two billion doses may not be enough, he said, underlining the importance of having multiple shots to combat the Coronavirus. “There was a hope that if we had a vaccine quickly enough, we could put out the pandemic,” Dr Hill said, noting the continuing surge of infections globally. I think its going to be very difficult to control this pandemic without a vaccine.

While Oxford’s data is promising, scientists said that the study was not conduct on how the human body responds once it has been infected with the Coronavirus. This, they say, is crucial for the development of vaccine.

Though the Oxford’s vaccine may provide some protection against the Coronavirus, it is still yet studied as some patients who have been cured of Coronavirus were reported to have been reinfected again.

Last week, US researchers announced that the first Covid-19 vaccine tested in the country boosted people’s immune systems just as scientists had hoped and the shots will now enter the final phase of testing.

That vaccine, developed by the National Institutes of Health and Moderna, produced the molecules key to blocking infection in volunteers who got it, at levels comparable to people who survived a Covid19 infection. Another trial led by China’s Jiangsu Provincial Centre for Disease Control and Prevention showed that more than 90 per cent of people showed either antibody or T cell immune responses between 14-28 days after being given the developmental vaccine.

The Chinese researchers used a weakened human cold virus modified to deliver genetic material that teaches cells to recognise the novel coronavirus. Side effects in both trials were moderate but authors of the Chinese study said they needed to test the vaccine safety on older patients. “Elderly people ... are an important target population for a

Covid-10 vaccine,” said Wei Chen, from the Beijing Institute of Biotechnology.

“It is possible that an additional dose may be needed in order to induce a stronger immune response in the elderly population.”