Updated: September 11, 2020 6:23:32 pm
An employee is treated at the Special Immunobiological Reference Center (CRIE) of the Federal University of Sao Paulo (Unifesp) where the Oxford / AstraZeneca coronavirus vaccine trials were being carried out, in Sao Paulo, Brazil. (Photo: REUTERS / Archive)
Serum Institute of India (SII) said on Thursday (September 10) that Pause ongoing clinical trials in India of the Covid-19 vaccine. candidate developed by the University of Oxford.
The move follows a notice of proven cause issued by the drug regulator to the Pune company about a single adverse reaction that was detected at one of the global testing sites.
IBS is sponsoring mid- and late-stage human clinical trials for the vaccine candidate in India. The company, the world’s largest vaccine manufacturer, has been contracted by the Swedish-British pharmaceutical giant AstraZeneca and the University of Oxford to manufacture the vaccine for low- and middle-income countries.
What is this vaccine?
This vaccine, one of the most watched candidates globally, works on a mechanism that uses a weakened chimpanzee virus of the common cold to carry instructions to become part of the SARS-CoV-2 virus as a Trojan horse.
Once injected, the virus will infect a cell and tell it to create the pointy outer shell of the virus, known as the ‘spike protein,’ the part of the virus that allows it to infect humans in the first place.
The body’s immune system is expected to recognize this spike protein as a threat and develop antibodies to fight it, so that it is ready to defend itself against the real virus.
What stage were testing in India before the break?
AstraZeneca had started global testing in the UK at the end of May. Since then, trials have also been conducted in countries such as Brazil and South Africa, and trials in India began on August 26.
The candidate, named AZD1222 globally, has been named ‘Covishield’ in India. The vaccine is in phase 2 human trials in the country and will be tested in 1,600 volunteers to see how well it helps the body develop an immune response.
📣 Express explained is now in Telegram. Click here to join our channel (@ieexplained) and stay up to date with the latest
About 100 of these 1,600 participants had been registered and vaccinated as of September 2. The test sites had stopped vaccinating more participants, because they had to observe this smaller group for seven days and submit the follow-up information for these participants to a Data Safety and Monitoring Board (DSMB).
This board would check to see if the vaccine was safe enough for trials to continue, and only after this clearance had been obtained could sites be able to vaccinate more participants.
So why has SII stopped trials in India?
The development stems from a decision by AstraZeneca to temporarily halt global trials of the candidate vaccine after a volunteer developed a “potentially unexplained illness.”
This volunteer reportedly enrolled in the UK trials arm and had reportedly developed a severe spinal inflammatory syndrome called transverse myelitis.
The pause, which means that the trial sites would not vaccinate more participants for now, was to allow an independent committee to review the safety data from the trials and to ensure that this “one-time” incident was not caused by the vaccine. .
Now, when AstraZeneca announced the pause (early 9th September India time), IBS initially said that this would not affect the Indian trials, which would continue, as no adverse reactions had been found in the vaccinated participants. so far in the country.
However, the firm did not officially inform the Comptroller General of Medicines of India (DCGI), which runs the country’s main drug regulatory body (CDSCO), about the global pause in trials.
So later on Wednesday (September 9), the DCGI sent a notice to the SII dealing with this, and asked the company to explain why the permit it was granted to conduct tests in India should not be suspended until establishing patient safety.
The IBS then decided to stop testing in India until the adverse reaction detected in the global trials was clarified.
Explanation of the coronavirus figures in India | Maharashtra is ready to hit the million mark
But if the adverse reaction was detected in only one participant and in a group of the trials not related to India, why did the IBS have to stop the trial?
Although this was just one incident detected in a trial of more than 10,000 participants, the fact remains that vaccine development timelines have been drastically shortened during the Covid-19 pandemic.
This makes it crucial to ensure that any unforeseen adverse reactions are thoroughly analyzed.
The fact that SII did not inform CDSCO about the global problem is significant because it is on the basis of data from previous global trials that the company received permission to skip the first phase of human testing that verifies the safety of the vaccine.
The regulator also noted that the SII had failed to present a “causality analysis”, an assessment of the relationship between a treatment and the occurrence of an adverse event, of the reaction observed in the UK volunteer.
Given the fact that the same vaccine is being tested around the world and in India, it is important to ensure that there is no possibility of a similar incident occurring in participants here, especially since the number of volunteers in India is much less than 5,000-10,000. who have been vaccinated in other countries.
In addition, CDSCO had granted SII permission to conduct the trials in India on the condition that clinical data generated from trials conducted by Oxford-AstraZeneca globally would also be taken into account when granting approvals.
Okay, but could this mean that the vaccine is not safe? Will testing ever be resumed?
This is only a temporary pause to make sure the adverse reaction was not caused by the vaccine.
It’s too early to come to any kind of conclusion about the safety of the vaccine – the problem has been reported in just one participant out of more than 10,000 volunteers, and the reaction may well be unrelated to the vaccine.
In fact, the goal of large late-stage trials is to give people the candidate vaccine without first doing an in-depth analysis of their underlying health conditions, so that the trial closely mimics the inoculation of entire populations.
In India, the DSMB is expected to review the safety data of the 100 trial participants in the country, and will likely also look at the adverse reaction data that was detected at the global site.
If the vaccine is found to be safe, and if the independent committee reviewing the data presented by AstraZeneca concludes the same, trials should resume everywhere.
Once phase 2 trials are complete, the candidate vaccine will move on to phase 3 trials, the last stage of testing, before the regulator decides whether it is safe and effective enough to be approved for the Indian population.
Have rehearsals been stopped this way before?
In fact, there have been previous cases of vaccine trials stopped for similar reviews, including in India.
For example, enrollment of volunteers to test a domestically developed rotavirus vaccine stopped for a few weeks after a similar incident occurred at one of the sites.
However, vaccination was resumed after the DSMB completed its investigations and gave the green light for trials to continue, according to the professor and former professor at Christian Medical College Vellore.
The executive director of the Translational Health Science and Technology Institute, Dr. Gagandeep Kang, who played a key role in the development of this vaccine.
The researchers say adverse events are likely to occur in large studies like these and that stopping the trial is an “integral part” of any vaccine trial.
📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay up to date with the latest headlines
For the latest news explained, download the Indian Express app.
© The Indian Express (P) Ltd
.
