Covid-19 vaccine update: What we know about Covovax and Serum Institute’s bridging study

Recently, Adar Poonawalla, CEO of Serum Institute of India (SII) said that the company will soon be working on the bridging study of Covovax vaccine and stockpiling its doses from April this year. It is to note that Covovax is the SII’s version of NVX-CoV2373 vaccine, which is protein-based and is developed by Novavax (headquartered in the USA), a report by The Indian Express noted. Last year in August, the two companies had an agreement where Novavax gave SII the licence to manufacture as well as supply the vaccine. These vaccine doses are to be supplied in low and middle-income countries along with India.

The agreement is aimed at providing support for supplying a minimum of 1 billion doses. The vaccine works like other vaccines targeting the spike protein on the surface of SARS-CoV-2. After a person gets this vaccine shot, the human body is expected to recognise the copy of spike proteins as a foreign substance and then work on building immunity against them. As a result, if and when the virus tries to infect the cell, the body will be able to fight it.

The report said that the vaccine has an efficacy of 96.4 per cent against mild to COVID-19 infection as per the ongoing late-stage global trials. Two weeks after the first dose of this vaccine is monitored, efficacy is noted at around 83.4 per cent.

For Covovax, SII will be testing the safety by using 1,600 participants in 19 sites across Delhi, Punjab, UP, Maharashtra, Karnataka, Kerala, Puducherry, Odisha and West Bengal. Participants between the ages of 18-99 years without acute illnesses or past history of Covid-19 or severe allergic reactions will be chosen for testing, the report noted. According to the report, the participants will be divided randomly. This will be done in a way that some participants will receive two doses of either Covovax, or the original NVX-CoV2373 vaccine made by Novavax, or a saline solution placebo, 22 days apart. The company and investigators will not be aware of who has received placebos and vaccines. The test is also likely to indicate whether Covovax possesses the same ability to prompt an immune response as NVX-CoV2373.

When it comes to scaling up the production of vaccines, Poonawalla said production can be impacted by the decision of countries like the US in regards to the indulgence of “raw material nationalism” during this pandemic. Meanwhile, SII is planning to stockpile Covovax from next month and may produce 40-50 million doses a month.