Hyderabad: Pausing trials for COVID-19 vaccine of AstraZeneca due to safety concerns is nothing new, scientists said while pointing out that ‘trials’ are experiments which may or may not work. The trials have been paused in India too by Serum Institute of India following instructions from the Drug Controller General of India.
The hype over an effective COVID-19 vaccine has created hope but ultimately every vaccine requires a time period and it has to cross various phases before it can be certified as safe. Reports from phase 1 and phase 2 trials were encouraging but in the phase 3 trials adverse effects were noted on two human subjects who volunteered for trials.
Director of the Center for Cellular and Molecular Biology (CCMB) Rakesh Mishra said, “They will now have to go back and understand what has gone wrong. The phase 3 trials are meant for a large number of people. As the vaccine is tried on different human bodies, the results are bound to be different.”
He said the importance of safety and efficacy, adverse side-effects and different responses are known only when the proposed vaccine is tried on a large number of people. “Science has noted 85 per cent rejection in vaccines. This does not mean that we will stop trying,” Mishra said.
The adverse effect of neurological symptoms has raised alarm across the world. It has dashed hopes of many who were looking forward to the vaccine as a safety net from the pandemic.
But scientists say that further evaluation is required to understand the adverse response of the human body. Meanwhile, two vaccine formulations developed by Russia are catching everyone’s attention but scientists remain skeptical.
A senior scientist with a private pharmaceutical company in Hyderabad said, “The number of human subjects for the vaccine from Russia is significantly less for drawing conclusions. The results of safety and efficacy will be known only after they are tested on more people. In the case of AstraZeneca, two people have reported adverse effects. Clarity will emerge when more trials are carried out.”