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The COVID Vaccine Clearances – All That you Need to Know

With the Drug Controller General of India (DGCI) giving go ahead on two vaccines to be rolled out in India, it is important to know the various details associated with it so that the confusion on the vaccines is cleared out.

What is the Exact Status on the Vaccines

The Subject Expert Committee of Central Drugs Standard Control Organisation (CDSCO) met on 1st and 2nd January, 2021 and made recommendations in respect of proposal for Restricted Emergency Approval of COVID-19 virus vaccine of M/s Serum Institute of India and M/s Bharat Biotech as well as Phase III clinical trial of M/s Cadila Healthcare Ltd.

The Subject Expert Committee consists of domain knowledge experts from the fields of pulmonology, immunology, microbiology, pharmacology, paediatrics, internal medicine, etc.

Serum Institute, Bharat Biotech Get Go Ahead

Data was presented by Serum Institute of India (SII) on their vaccine related to safety, immunogenicity and efficacy, generated on 23,745 participants aged 18 years or older from overseas clinical studies. The overall vaccine efficacy was found to be 70.42%. After detailed deliberations the DGCI committee on this issue recommended the grant of permission for restricted use in emergency situation subject to certain regulatory conditions. Also, Further, SII was granted permission to conduct Phase-II/III clinical trial on 1,600 participants within India.

Bharat Biotech has developed a Whole Virion Inactivated Corona Virus Vaccine (Covaxin) in collaboration with ICMR and NIV (Pune). The firm has generated safety and immunogenicity data in various animal species. Further, Phase I and Phase II clinical trials were conducted in about 800 subjects and the results have demonstrated that the vaccine is safe and provides a robust immune response.  The Phase III efficacy trial was initiated in India in 25,800 volunteers and till date, ~22,500 participants have been vaccinated across the country and the vaccine has been found to be safe as per the data available till date.

Another Company Receives Clearance for Trials

Cadila Healthcare Ltd. has developed a Novel Corona Virus-2019-nCov-Vaccine using DNA platform technology. The firm has initiated Phase-I/II clinical trial in India in more than 1,000 participants, which is ongoing. Interim data suggests that the vaccine is safe and immunogenic with three doses when administered intradermally. Accordingly, firm has sought permission to conduct Phase-III clinical trial in 26,000 Indian participants, for which it received permission.

Health Minister Explains the Process and the Efficacy of COVAXIN

Amid the politicization of the COVID vaccine, Minister for Health and Family Welfare Dr. Harshvardhan took to Twitter to explain how vaccines get approved, and why COVAXIN may actually be far more effective than estimated as of now.

Dr. Harshvardhan pointed out that vaccines approved globally are based on gene encoding spike proteins and have protective efficacy of over 90%. However, COVAXIN is based on whole inactivated virus has other antigenic epitopes in addition to spike protein. So,it’s likely to have similar protective efficacy reported for others.

Dr. Harshvardhan also said that COVAXIN is more likely to work against newer variants like N501Y Variant (UK variant) and any other that may arise due to antigenic drift as it contains immunogens (epitopes) from other genes in addition to those from Spike protein. Interestingly, he added that the inactivated virus from NIV also had D614G mutation. He pointed out that data from COVAXIN Phase I and II clinical trials showed it not only produced neutralizing antibodies in all participants but also sensitised  CD4 T lymphocytes that imparts durable immune response.

Further, Dr. Harshvardhan laid to rest concerns about reactions by saying that experience with inactivated vaccines saw no serious adverse events being observed in Phase II done among 380 study participants in BBV152 trial in 21,280 Person days follow up. He also highlighted how only 7% persons receiving 6 microgram dose had mild symptoms.