First human trial of Oxford Covid-19 vaccine shows promise

SCIENTISTS at Oxford University have said 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.

The vaccine, called AZD1222 and being developed by AstraZeneca and scientists at the United Kingdom's University of Oxford, did not prompt any serious side effects and elicited antibody and T-cell immune responses, according to trial results published in The Lancet medical journal yesterday.

In the research, scientists said that they found their experimental Covid-19 vaccine produced a dual immune response in people aged 18 to 55 that lasted at least two months after they were immunised.

"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.

Hill said neutralising antibodies are produced — molecules which are key to blocking infection.

He said larger trials evaluating the vaccine's effectiveness, involving about 10 000 people in the UK as well as participants in South Africa and Brazil are still under way. Another big trial is slated to start in the US soon, aiming to enrol about 30 000 people.

Al Jazeera's Paul Brennan, reporting from Oxford city, said the progress looks hopeful but there are no guarantees at this stage.

"The ideal vaccine needs to be effective after one or two doses, it must be good for elderly people and target participants such as people with existing health conditions,

"It also needs to be effective for a period of longer than six months and at this stage its too early to say whether or not this vaccine actually meets those criteria," he said.

Wafaa el-Sadr, professor of epidemiology and medicine at Columbia University, also urged caution.

"This phase 1 and 2 study was done on a little more than a 1 000 participants. Sometimes you really need to study on a much larger population in order to see the rare side effects," he told Al Jazeera.

"I do think it is improtant to stress that we cannot let our guard down as yet as we dont have a vaccine in hand, and for the foreseeable future, we will have to continue to be careful to adhere to the public health measures that can prevent transmission of this virus."

How quickly scientists are able to determine the vaccine’s effectiveness will depend largely on how much more transmission there is, but 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.

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.

“There was a hope that if we had a vaccine quickly enough, we could put out the pandemic,” Hill said, noting the continuing surge of infections globally.

“I think it’s going to be very difficult to control this pandemic without a vaccine.”

AstraZeneca’s is among the leading vaccine candidates against a pandemic that has killed more than 600 000, alongside others in midand late-stage trials.

AstraZeneca has signed agreements with governments around the world to supply the vaccine should it prove effective and gain regulatory approval.

The company has said it will not seek to profit from the vaccine during the pandemic. — Aljazeera.