Vaccine safety top priority

Safety of a prospective Covid-19 vaccine comes "first and foremost", the World Health Organization's chief scientist said yesterday, as a trial of a leading candidate from AstraZeneca was paused due to concerns over side effects.

Rollout of an effective vaccine is seen as a crucial step in helping battered economies recover from the coronavirus pandemic.

"Just because we talk about speed...it doesn't mean we start compromising or cutting corners on what would normally be assessed," Dr Soumya Swaminathan said in a social media event.

"The process still has to follow through rules of the game. For drugs and vaccines which are given to people, you have to test their safety, first and foremost," she said.

WHO officials did not immediately respond directly to questions from Reuters over the move by AstraZeneca to pause global trials, including large late-stage trials, of its experimental coronavirus vaccine due to an unexplained illness in a study participant.

The vaccine, which AstraZeneca is developing with the University of Oxford, has previously been described by the WHO as probably the world's leading candidate and the most advanced in terms of development.

AstraZeneca said it voluntarily paused trials to allow an independent committee to review safety data.

US infectious disease expert Anthony Fauci said yesterday that AstraZeneca's decision to pause global trials was unfortunate but not an uncommon safety precaution in a vaccine development process.

Fauci hoped the company could proceed with its trial.

The WHO is in the midst of rounding up support for a global coalition, called the ACT Accelerator, in the hope of fairly distributing vaccines, treatments and diagnostics for the new coronavirus to rich and poor countries alike.

In addition to 92 lower-income countries seeking aid, some 79 wealthier countries have expressed interest, with a September 18 deadline for binding commitments.

But some countries that have struck their own vaccine deals, including the United States which is not joining the WHO effort.

The vaccine pillar of ACT, called COVAX, hopes to secure enough vaccine to deliver 2 billion doses by the end of 2021, though concrete fund raising has, so far, lagged goals. Volume buying and possible tiered pricing offered by some manufacturers could help make a vaccine more affordable, Swaminathan said.

"You need to come together. Essentially, if every country and every organisation tries to do this on their own, it's going to be long and hard and difficult," she said. "This is the first time that the world will need vaccines in the billions of doses."

SAFETY PLEDGE

Meanwhile, the CEOs of nine companies developing vaccines against Covid-19 on Tuesday pledged to "uphold the integrity of the scientific process" amid concern Donald Trump will pressure regulators to approve a vaccine ahead of the presidential election in November.

"We, the undersigned biopharmaceutical companies, want to make clear our ongoing commitment to developing and testing potential vaccines for Covid-19 in accordance with high ethical standards and sound scientific principles," said the CEOs.

The statement was signed by AstraZeneca, BioNTech, GlaxoSmithKline, Johnson & Johnson, Merck, Moderna, Novavax, Pfizer and Sanofi.

Specifically, the companies said they would only seek emergency authorisations for vaccines "after demonstrating safety and efficacy through a Phase 3 clinical study that is designed and conducted to meet requirements of expert regulatory authorities such as FDA," the Food and Drug Administration.

Some experts and former officials of this agency worry it has become politicised after it issued emergency use authorisations for two Covid-19 treatments without sufficient proof, reports AFP.

Both hydroxychloroquine, whose authorisation was later revoked over safety fears, and blood plasma from recovered Covid-19 patients, were touted by Trump.

Joe Biden, the Democratic candidate for president, has accused Trump of "undermining public confidence" by regularly raising the possibility a vaccine will be ready ahead of the election on November 3.

Stephen Hahn, the head of the FDA, has also guaranteed that only science will decide when a vaccine is ready.

In theory, the FDA has to rely on independent expert committees that oversee clinical trials before they give their green light. The makers themselves must also apply for authorisation.

Among the companies, Moderna and Pfizer are in the most advanced stages of their trials, and the US Centers for Disease Control and Prevention (CDC) has asked states to have distribution networks ready by November 1.

Fauci, director of the National Institute of Allergies and Infectious Diseases in US, has said the results of clinical trials aren't expected to be known until the final two months of the year.

"I think it's extremely unlikely but not impossible," that the trials will have results to show before the election, Moncef Slaoui, the scientific head of the White House program tasked with producing and delivering vaccine doses, said.