Oxford vaccine prompts immune response in elderly: AstraZeneca

An experimental COVID-19 vaccine being developed in the United Kingdom produces an immune response in both younger and older adults, British drug maker AstraZeneca said, raising hopes in the fight against the coronavirus pandemic.

The vaccine, developed by the University of Oxford, also triggers lower adverse responses among the elderly, AstraZeneca, which is helping manufacture the vaccine, said on Monday.

This could potentially be seen as a game-changer in the battle against the novel coronavirus, which has infected more than 43 million people worldwide, killed at least 1.15 million people, shuttered swathes of the global economy, and turned normal life upside down for billions of people.

“It is encouraging to see immunogenicity responses were similar between older and younger adults and that reactogenicity was lower in older adults, where the COVID-19 disease severity is higher,” an AstraZeneca spokesman said.

“The results further build the body of evidence for the safety and immunogenicity of AZD1222,” the spokesman said, referring to the technical name of the vaccine.

AstraZeneca did not provide details of the data behind the statement or say when it would publish eagerly awaited late-stage phase-three trial data, which would show whether the vaccine works well enough in large-scale trials for it to be approved.

The Oxford/AstraZeneca vaccine is expected to be one of the first from big pharma to secure regulatory approval, along with Pfizer and BioNTech’s candidate, as the world tries to plot a path out of the COVID-19 pandemic.

The news that older people get an immune response from the vaccine is positive because the immune system weakens with age and older people are those most at risk of dying from the coronavirus.

British Health Secretary Matt Hancock said a vaccine was not yet ready, but he was preparing logistics for a possible roll-out mostly in the first half of 2021.

Asked if some people could receive a vaccine this year, he told the BBC: “I don’t rule that out but that is not my central expectation.

“The programme is progressing well [but] we’re not there yet,” Hancock said.

‘Robust immune responses’

Work began on the Oxford vaccine in January. Called AZD1222 or ChAdOx1 nCoV-19, the viral vector vaccine is made from a weakened version of a common cold virus that causes infections in chimpanzees.

The chimpanzee cold virus has been genetically changed to include the genetic sequence of the so-called spike protein the coronavirus uses to gain entry to human cells. The hope is that the human body will then attack the novel coronavirus if it sees it.

Annelies Wilder-Smith, professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine, said phase-three trials, which involve wide-scale testing with tens of thousands of participants, are a “prerequisite for licensing” before the vaccine can be rolled out to the masses.

“We do not know the efficacy at this point and that is why we are eagerly awaiting the phase-three trial results,” she told Al Jazeera from Lucerne, Switzerland.

According to early trial results published in the medical journal The Lancet in July, the AZD1222 vaccine generated “robust immune responses” in a group of healthy adults aged between 18 and 55, without any serious side effects.

Details of the latest findings are expected to be published shortly in a clinical journal, the Financial Times reported. It did not name the publication.

People aware of the results from so-called immunogenicity blood tests carried out on a subset of older participants say the findings echo data released in July.

AstraZeneca has signed several supply and manufacturing deals with companies and governments around the world as it gets closer to reporting early results of a late-stage clinical trial.

It resumed the United States trial of the experimental vaccine after approval by US regulators, the company said on Friday.

More than 200 vaccine candidates are currently in development globally. About a dozen, including the Oxford vaccine and US biotech firm Moderna’s candidate, have reached phase-three trials.

Wilder-Smith said there is a possibility that several vaccines could be rolled out simultaneously.

“Probably the first two vaccines will come at around the same time and then new additional vaccines will come out,” she said.

“The intent is that by the end of 2021, we would have two billion doses of vaccine that would be fairly distributed to countries around the world.”