The United States, China and Europe have been scrambling to find a cure for Covid-19 in a race to become the first to produce a vaccine amid rising global death toll coupled with the worsening economic crisis.

In this file photo taken on August 13, 2020 Biotechnology company Moderna protocol files for Covid-19 vaccinations are kept at the Research Centres of America in Hollywood, Florida. US biotech firm Moderna won't seek an emergency use authorization for its coronavirus vaccine before November 25, its CEO told the Financial Times on September 30.
In this file photo taken on August 13, 2020 Biotechnology company Moderna protocol files for Covid-19 vaccinations are kept at the Research Centres of America in Hollywood, Florida. US biotech firm Moderna won't seek an emergency use authorization for its coronavirus vaccine before November 25, its CEO told the Financial Times on September 30. (AFP)

Countries around the world are rushing to book upcoming coronavirus vaccines. Effective vaccines are seen as essential to help end a coronavirus pandemic that has killed more than one million people worldwide. 

Here’s what you need to know about the coronavirus vaccine right now:

US inquiry into AstraZeneca's vaccine

The US Food and Drug Administration has broadened its investigation of a serious illness in AstraZeneca Plc's Covid-19 vaccine study and will look at data from earlier trials of similar vaccines developed by the same scientists, three sources familiar with the details told Reuters.

AstraZeneca's large, late-stage US trial has remained on hold since September 6, after a study participant in Britain fell ill with what was believed to be a rare spinal inflammatory disorder called transverse myelitis. 

The widened scope of the FDA probe raises the likelihood of additional delays for what has been one of the most advanced Covid-19 vaccine candidates in development. The requested data was expected to arrive this week, after which the FDA would need time to analyze it, two of the sources said.

READ MORE: AstraZeneca's Covid-19 vaccine trial suspended after volunteer falls ill

The administration of President Donald Trump has pledged $1.2 billion to support development of the AstraZeneca vaccine and secure 300 million doses for the United States. Other leading companies in the US vaccine race include Pfizer Inc, Moderna Inc and Johnson & Johnson.

Regulators in the UK, Brazil, India and South Africa have allowed AstraZeneca to resume its clinical trials there.

The FDA, however, wants to determine whether similar side effects emerged in trials of other vaccines designed by AstraZeneca's coronavirus vaccine partner, researchers at Oxford University, the sources said. That does not mean the agency believes there were safety issues associated with any of these vaccines, they added.

"It just shows that the FDA is being thorough," said one of the sources.

READ MORE: When will a Covid-19 vaccine be ready? 

Further complicating the situation is that the data requested by the FDA is in a different format than what the US regulator requires, two of the sources said.

The FDA declined to comment on discussions involving an experimental product. Oxford did not respond to requests for comment. AstraZeneca, in a statement, said, "We are continuing to work with the FDA to facilitate review of the information needed to make a decision regarding resumption of the US trial."

Viral vector 

All of the vaccines it wants to review use a modified adenovirus as vectors to safely deliver genetic material from the target illnesses – flu, Middle East Respiratory Syndrome, and other diseases – into the body to stimulate an immune system response to fight future infection.

While other vaccine developers have used human adenoviruses for such vaccines, the Oxford researchers chose an adenovirus found in chimpanzees. They felt this would reduce the likelihood that an individual's immune system would attack the vector virus due to prior exposure rather than the intended target.

READ MORE: Oxford Covid-19 vaccine data likely to reach regulators this year

Reuters reviewed six research papers that detailed safety data of vaccines using the engineered chimpanzee adenovirus called ChAdOx1 for diseases including tuberculosis, prostate cancer and influenza.

In one of those trials, one serious adverse event cited by researchers was deemed unrelated to the vaccine.

The type of review being conducted by the FDA is generally intended to scrutinize raw data for other side effects, the sources said.

EU regulator reviews AstraZeneca’s vaccine

After several global trials of the vaccine were halted due to an unexplained illness in a study participant, the European health regulator said on Thursday it started a rolling review of the experimental Covid-19 vaccine from AstraZeneca and Oxford University, aiming to speed up any future approval process.

The European Medicines Agency (EMA) said its human medicines committee has started evaluating the first batch of data on the vaccine, and will continue till sufficient data is available and a formal application is submitted.

Second Russian virus vaccine passes early trials

Early clinical trials of a second Russian coronavirus vaccine have proved successful, its developer said on Thursday after Russia boasted of approving the world's first vaccine.

Russia's Vektor – a top-secret state virology research centre in Siberia – said that early-stage trials were successful for its own experimental vaccine, named EpiVacCorona.

"The first two phases of clinical trials demonstrated the effectiveness and safety of the EpiVacCorona vaccine," Vektor's press department told the Interfax news agency.

READ MORE: Russia starts giving Covid-19 vaccine to volunteers

Russia announced in August that it had developed the world's first registered vaccine – named "Sputnik V" after the world's first satellite.

It raised concerns among Western scientists by announcing that the vaccine – developed by Moscow's Gamaleya research centre – had received approval before full clinical trials have been completed.

Vektor said it would be possible to make the final conclusions about the efficacy of its vaccine, based on peptides that trigger an immune response, after post-approval clinical trials have been completed.

Russian Health Minister Mikhail Murashko told President Vladimir Putin this week that Vektor's vaccine could be approved by the ministry in three weeks. 

Moderna's vaccine won't be ready by US election

US biotech firm Moderna won't seek an emergency use authorization for its coronavirus vaccine before November 25, its CEO told the Financial Times on Wednesday.

The news deals a blow to President Donald Trump's hopes of having an injection ready before the election to give his campaign a much-needed boost.

Stephane Bancel told the newspaper, "November 25 is the time we will have enough safety data to be able to put into an EUA file that we would send to the FDA (Food and Drug Administration) – assuming that the safety data is good, ie a vaccine is deemed to be safe."

Trump, whose approval has taken a hit over his handling of the Covid-19 crisis, has frequently hinted a vaccine could be ready before the November 3 vote.

READ MORE: US inks $1.5B deal with Moderna for 100M Covid-19 vaccine doses

This has raised concern among experts that his administration may attempt to interfere with the regulatory process for political reasons.

Moderna's vaccine is one of 11 experimental vaccines in final stage trials. Another is being developed by Pfizer, whose CEO Albert Bourla has taken the position that his company may have a clear answer about whether their shot works by October.

Most experts are skeptical of the claim, believing that the ongoing trials will not have sufficient statistical data to prove the drug's safety and effectiveness by that time.

Chile approves clinical trials for Sinovac, J&J vaccines

Chilean health authorities have said they have approved the start of clinical trials for coronavirus vaccines under development by China's Sinovac and Johnson & Johnson pharmaceutical unit Janssen.

The trials, authorized by Chile's Institute of Public Health (ISP), will be conducted by government health officials and researchers from two Chilean universities, authorities said.

Pharmaceutical company AztraZeneca, whose trials are partially on hold after one of the participants fell ill, has also applied to begin studies in Chile.

READ MORE: Vaccine nationalism to make Covid-19 worse

Brazil, Chile, Peru and Colombia have had the highest rates of viral infections in South America, making them attractive testing sites for vaccine developers because it is easier to get dependable trial results in areas with high rates of active transmission and infection.

"Chile can and must participate in these clinical Phase III studies to approve, study and hopefully move forward the development of these vaccines," Health Minister Enrique Paris told reporters.

Large-scale Phase III clinical trials can be the final step before a drug or vaccine is submitted for regulatory approval.

READ MORE: Here's why you won't see a mass Covid-19 vaccine until mid-2021

Source: Reuters