In what could be a setback for the search for a vaccine against COVID-19, pharmaceutical giant AstraZeneca and University of Oxford have temporarily halted the stage 3 testing of a prospective vaccine they have developed after one of the volunteers participating in the trial became ill. At this stage, it is not clear whether the illness is caused by the reaction of the vaccine.

The pharma company issued a statement where it informed that the temporary stoppage is part of the protocol for the testing. Now, an investigation will be conducted by the company to ascertain whether the illness of the volunteer was an adverse reaction to the vaccine or the result of other factors. The nature of the illness has not been revealed.

Vaccine Human Trial
This vaccine is being developed through a collaboration between Oxford University and AstraZeneca YouTube Grab

Critical Stage in Testing

Stage 3 is the most crucial in the testing process of potential vaccines. Many candidates for the highly-awaited vaccine have previously sailed through the first two stages only to fail in this stage.

"As part of the ongoing randomized, controlled global trials of the Oxford coronavirus vaccine, our standard review process was triggered and we voluntarily paused vaccination to allow the review of safety data by an independent committee," AstraZeneca's official statement on the development read.

"This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials, while it is investigated, ensuring we maintain the integrity of the trials. In large trials illnesses will happen by chance but must be independently reviewed to check this carefully," it further added.

COVID-19 vaccine
Two other prominent candidates for vaccine are undergoing trials

Search for Vaccine

As of now, apart from this potential vaccine, there are two other candidates which are in stage 3 of their trials in USA. One of these has been developed by Pfizer and BioNTech, while the other is the creation of Moderna.

Of course, Sputnik V, the 'vaccine' developed by Russian government-backed scientists is already being widely used in the country and, according to the claims of the government in that nation, is proving to be successful. But many outside Russia doubt the validity of the claims.

As of now, there is no information regarding the amount of time the trial will remain suspended. Since stage 3 testing also involves giving placebos to some of the participants, so as to ensure that the placebo effect doesn't get mistaken for the success of medical formula, it might turn out that the volunteer who has taken ill did not consume the potential vaccine but the placebo.