AIIMS starts recruiting volunteers for Covaxin trial
The All India Institute of Medical Sciences (AIIMS), Delhi, began recruiting on Monday healthy participants for the continuous phase 1 and 2 trial of Covaxin, jointly developed by the Indian Council of Medical Research (ICMR) and Hyderabad-based Bharat Biotech.
It is one of the 12 centres that will test the safety and immunogenicity, the ability of a substance to provoke an immune response in the body, of the vaccine candidate. “In the phase 1 trial, the vaccine will be given to a small number of people to see whether it is safe. In phase 2, we will check the immune response it produces. For that, we will have to check the antibody level of the participants as Covid-19 can be asymptomatic in many. We have a target of 100 patients. The trial vaccine will be given in an area close to the hospital emergency in case someone goes into anaphylaxis (an allergic reaction that can close the airway of a person),” said Dr Randeep Guleria, director, AIIMS Delhi.
Apart from the immediate reactions, the participants will also be followed up for 28 days and a longer period to check for any adverse effects.
The participants will receive three combinations with different adjuvants – an agent that improves the immune response -- of the vaccine in either 3 microgram or 6 microgram doses. Apart from figuring out the correct dose, the investigators will also look at whether the immune response is long-lasting.
“We need a vaccine that is first and foremost safe, the triggers and immune response, and that immunity lasts for at least a year or two. If it just lasts for six weeks, then it is of no use. Fortunately, from what we have learnt so far, the mutations in the virus have not been very significant or the antigenic drift is not as fast as the flu for which vaccine has to be taken every year. The mutations reported so far have not been in the spike protein that is the target of vaccines,” said Dr Guleria.
In just 24 hours after seeking applications from people, the hospital received 1,000 applications against its requirement of 100 volunteers. Dr Guleria said the centre may be able to finish the trial in two to three months if the screening goes well.
“Normally, a vaccine takes about 10 years to develop. That is because the different phases of the trial are conducted one after the other after evaluation of the results. It is a financial risk if everything is done simultaneously as all vaccine candidates do not work and scientists might have to go back to the drawing board. But, in this case, everything is happening simultaneously. Even as the effectiveness of the vaccine is being studied, manufacturing capacity is also being built,” said Dr Guleria.