Vaccine still possible this year, despite trial pause: AstraZeneca

Drugs giant AstraZeneca on Thursday said a COVID-19 vaccine could still be available by as early as the year end, despite a randomized clinical trial being paused.

"We could still have a vaccine by the end of this year, early next year," the UK-based company's chief executive Pascal Soriot said in comments at a media event.

AstraZeneca announced on Wednesday it had "voluntarily paused" its trial of a vaccine developed alongside Oxford University after a UK volunteer developed an unexplained illness.

An independent committee was drafted in to review safety but the company said it was a "routine action" designed to maintain the integrity of the trials.

"We will be guided by this committee as to when the trials could restart, so that we can continue our work at the earliest opportunity," Soriot said in a statement.

AstraZeneca's vaccine candidate is one of nine around the world currently in late-stage Phase 3 human trials.

In the US, the company began enrolling 30,000 volunteers across dozens of sites on August 31, and smaller groups are being tested in Brazil and elsewhere in South America.

The vaccine, called AZD1222, uses a weakened version of a common cold-causing adenovirus engineered to code for the spike protein that the novel coronavirus uses to invade cells.

After vaccination, this protein is produced inside the human body, which primes the immune system to attack the coronavirus if the person is later infected.

The World Health Organization said the development was "a good wake-up call... that there are ups and down in research."

"We don't need to be overly discouraged because these things happen," WHO chief scientist Soumya Swaminathan told a virtual press conference.

Britain's chief scientific adviser, Patrick Vallance, on Wednesday said similar events should be expected but progress on vaccines and therapeutics was positive overall.

UK Health Secretary Matt Hancock said the pause was "not necessarily" a set-back, and said a similar pause occurred recently but was "resolved without a problem."