BYL Nair Hospital in Mumbai Central has become the first civic-run hospital to start the phase 3 clinical trial of Zydus Cadila’s ZyCoV-D vaccine in children, in the city.
A total of 50 children between the age 12 and 17 will be enrolled for the trial. Half of the volunteers will be given placebo, a false replica of the vaccine. The primary objective of the clinical trial is to demonstrate the efficiency of ZyCoV-D in the prevention of symptomatic Covid-19 cases as compared to placebo.
The enrolment of volunteers has begun at the hospital. The volunteers will have to be healthy, without any severe comorbidities. The participants will be asked to maintain a diary of daily health updates and submit it to the hospital for a consultation, said a senior doctor. As part of the trial, three doses will be administered to the volunteers. After the first dose, the second and third doses will be given after a gap of 28 and 56 days.
Zydus Cadila had announced that ZyCoV-D covid vaccine showed 66.6% primary efficacy in their interim analysis on July 1. ZyCoV-D is a three-dose, intradermal vaccine, which is applied using the PharmaJet needle-free system, which can also lead to a significant reduction in any side effects. Also, being a plasmid DNA vaccine, ZyCoV-D doesn’t have any problem associated with vector-based immunity, says the company.
The vaccine uses a genetically engineered DNA molecule known as a plasmid which is coded to generate spike protein of Sars-CoV-2. The plasmid gains entry in multiple cells such as myocytes, keratinocytes, and antigen-presenting cells (APCs). It enters the nucleus as an episome without getting integrated into the host cell DNA. Using the host cell’s transcription and translation machinery, the inserted gene gets translated into antigen. A protein expressed by plasmid-transfected cells is likely to be expressed within the cell and folded in its native configuration. The antigen is recognised by APCs and further induces antibodies and cellular response.The technology can be easily adapted to mutations in the coronavirus, says the company.
The vaccine can be stored at a temperature between two and eight degrees Celsius and has shown good stability at 25 degrees Celsius for at least three months. The manufacturer has recently applied to the Drug Controller General of India (DCGI) for emergency use authorisation (EUA) of the vaccine.
“In the second wave, we have seen that a large number of children contracted Covid-19 infection. If this vaccine proves to be effective among children then it will be a great relief for parents since there is no vaccine available in the market for children as of yet,” said Dr Ramesh Bharmal, dean of the hospital.
“As seen in BMC’s serosurvey, almost 50% surveyed children had antibodies, which indicates that a large number of children had contracted Covid-19 but remained undiagnosed. Hence, there is a need for a vaccine for children especially when cities are planning to open schools,” said Dr Bela Verma, a paediatrician from Sir JJ Hospital.