When will coronavirus vaccine be ready?

Final clinical trials for a coronavirus vaccine, developed by AstraZeneca and Oxford University, have been put on hold after a participant had an adverse reaction in the UK. Report informs citing the BBC.

AstraZeneca described it as a "routine" pause in the case of "an unexplained illness."

The outcome of vaccine trials is closely watched around the world.

The AstraZeneca-Oxford University vaccine is seen as a strong contender among dozens developed globally.

Hopes have been high that the vaccine might be one of the first to come on the market, following successful phase 1 and 2 testings.

Its move to Phase 3 testing in recent weeks has involved some 30,000 participants in the US and the UK, Brazil, and South Africa. Phase 3 trials in vaccines often include thousands of participants and can last several years.

Stat News, the health website which first broke the story, said details of the UK participant's adverse reaction were not immediately known but quoted a source as saying they were expected to recover.

At first glance, this may seem alarming. A vaccine trial - and not just any vaccine, but one receiving massive global attention - is put on hold due to a suspected severe adverse reaction. But such events are not unheard of. Indeed the Oxford team describes it as "routine." Any time a volunteer is admitted to a hospital, and the cause of their illness is not immediately apparent, it triggers a study to be put on hold.

This is the second time it has happened with the Oxford University/AstraZeneca coronavirus vaccine trial since the first volunteers were immunized in April. An Oxford University spokesperson said: "In large trials, illnesses will happen by chance but must be independently reviewed to check this carefully."

A final decision on restarting the trial will be taken by the medical regulator, the MHRA, which could take only days. But until then, all international vaccination sites in the UK, Brazil, South Africa, and the USA are on hold.

The Oxford University team believes this process illustrates that they are committed to their volunteers' safety and the highest standards of conduct in their studies.

US President Donald Trump has said he wants a vaccine available in the US before the 3 November's election. Still, his comments have raised fears that politics may be prioritized over safety in a vaccine rush.

On Tuesday, a group of nine Covid-19 vaccine developers sought to reassure the public by announcing a "historic pledge" to uphold scientific and ethical standards in the search for a vaccine.

AstraZeneca is among the nine firms that signed up to the pledge to only apply for regulatory approval after vaccines have gone through three clinical study phases.

Industry giants Johnson & Johnson, BioNTech, GlaxoSmithKline, Pfizer, Merk, Moderna, Sanofi, and Novavax, are the other signatories.

They pledged to "always make the safety and well-being of vaccinated individuals our top priority."

The World Health Organization (WHO) says nearly 180 vaccine candidates are being tested worldwide, but none has yet completed clinical trials.

The organization has said it does not expect a vaccine to meet its efficacy and safety guidelines to be approved this year because of its time to test them safely.

Similar sentiments have been shared by Thomas Cueni, director-general of the International Federation of Pharmaceutical Manufacturers. The industry body represents the companies that signed the pledge.

Despite this, China and Russia have begun inoculating some key workers with domestically developed vaccines. The WHO still lists all of them as being in clinical trials.

Meanwhile, the US national regulator, the Food and Drug Administration (FDA), has suggested that coronavirus vaccines may be approved before completing the third phase of clinical trials.

Last week it also emerged that the US Centers for Disease Control and Prevention had urged states to consider waiving specific requirements to be ready to distribute a potential vaccine by 1 November - two days before the 3 November presidential election.

Although President Trump has hinted that a vaccine might be available before the election, his Democratic rival Joe Biden has expressed skepticism that D. Trump will listen to scientists and implement a transparent process.