Covaxin is an investigational vaccine candidate for COVID19. It is in Phase III clinical trial as of today (20-Dec-2020). It is being developed by Bharat Biotech and Indian Council of Medical Research.
What is ‘Covaxin’ and how was it developed?
Bharat Biotech, in collaboration with the Indian Council of Medical Research (ICMR), the National Institute of Virology (NIV), developed the vaccine candidate.
NIV isolated a novel coronavirus strain from an asymptomatic Covid-19 patient and transferred it early in May to Bharat Biotech.
The firm then used it at its high-containment facility in Hyderabad to work on developing a “inactivated” vaccine, a vaccine that uses the dead virus.
When administered into a human, the vaccine has no ability to infect or replicate, since it is a killed virus.
It simply acts as a dead virus for the immune system and mounts an antibody response to the virus,’ the company said, adding that inactivated vaccines typically have a proven safety record.
Before the company approached CDSCO (Central Drugs Standard Control Organisation) for permission to move on to human trials, Covaxin then underwent pre-clinical testing on animals such as guinea pigs and mice to see if it was safe.
Details of Clinical trials with Covaxin:
The vaccine earned DCGI approval for Phase I & II Human Clinical Trials, and studies began in July 2020 across India.
Following the successful completion of the interim analysis of the COVAXINTM Phase I & II clinical trials, Bharat Biotech received DCGI approval for Phase 3 clinical trials from 26,000 participants in more than 25 centers across India. Initially, the total patient population of the Phase I and II trials was set at 1,125 participants-375 in Phase I and 750 in Phase II. The Phase II population was almost halved to 380 volunteers
Other formulations of Covaxin:
Three vaccine formulations were prepared with 3µg and 6µg with Algel-IMDG 148 (BBV152A and BBV152B, respectively) and 6µg with Algel (BBV152C).
Phase I/II trial
Title of the study “An Adaptive, Seamless Phase 1, Followed by Phase 2 Randomized, Double-blind, Multicenter Study to Evaluate the Safety, Reactogenicity, Tolerability and Immunogenicity of the Whole-Virion Inactivated SARS-CoV-2 Vaccine (BBV152) in Healthy Volunteers”
Three formulation of the vaccines were tested: BBV152A, BBV152B and BBV152C
These are intramuscular formulations.
Another Phase I/II trial:
A Phase 1, Followed by a Phase 2, vaccine given Randomly in subjects in different sites to Evaluate the Safety, side effects, and resistance of the Virus Vaccine, BBV152D Administered between the layers of the skin(intradermal) in Healthy Volunteers.
Intradermal formulations tested (BBV152D) (this is the fourth formulation in addition to BBV152A, BBV152B and BBV152C )
Phase I results summary
- All subjects who administered the vaccine intramuscularly had substantially elevated Spike binding IgG antibodies and Neutralizing Antibody titers on day 28 (14 days after the 2nd dose).
- Both homologous (vaccine virus strain) and heterologous (divergent) SARS-CoV-2 strains were able to neutralize the reported vaccine-induced antibody responses.
- Local reactions and systemic events after immunization were normally mild in nature and resolved transiently. No serious (grade 3-4) adverse events were reported.
Phase III trial
Official title of the study:
“An Event-Driven, Phase 3, Randomized, Double-blind, Placebo-controlled, Multicenter Study to Evaluate Efficacy, Safety, Immunogenicity, Lot-to-Lot Consistency of BBV152, a Whole-Virion Inactivated SARS-CoV-2 Vaccine in Adults≥18 Yrs of Age”
Phase III trial is testing BBV152B (6µg-Algel-IMDG) formulation which should be given Intramuscularly
Dose, Duration and route of administrations:
As per the Phase III trial design, we can say that company is developing the intramuscular formulation of the vaccine candidate, however they conducted Phase I/II study with intradermal formulations as well, but Phase III is not registered with this formulation type.
Duration of treatment: two dose of the vaccine need to be given 28 days apart (IM).
COVAX and COVID-19 Tools (ACT) Accelerator:
The ACT Accelerator is a ground-breaking global collaboration in order to accelerate the development, production, and reasonable access to COVID-19 tests, treatments, and vaccines.
COVAX is co-led by Gavi, the Coalition for Epidemic Preparedness Innovations (CEPI) and WHO.
Its aim is to accelerate the development and manufacture of the COVID-19 vaccines, and also, to guarantee fair and equitable access for all countries in the world.
It should be noted that COVAXIN is one of three COVID-19 vaccines Bharat is developing. The other two are being developed with Thomas Jefferson University and the University of Wisconsin-Madison. which are in early stage (preclinical) of development.
Status of COVAXIN
Covaxin is in Phase III stage of development. There are many fake news around regarding rejection of its application for emergency use authorization in India. Bharat Biotech has not applied for it yet.
Other snapshot from the news:
“Based on the success of late-stage trials, which started in November 2020, a senior Indian government scientist told Reuters on November 5, COVAXIN could be launched as early as February 2021, months ahead of schedule”.
“The vaccine has shown good efficacy,” said senior ICMR scientist Rajni Kant at the New Delhi headquarters of the research council, who is also a member of its COVID-19 task force.
“At the Post-Graduate Institute of Medical Sciences, Rohtak, principal investigator of the Phase I trial, Savita Verma, MBBS, told the Indian Economic Times that no adverse events were reported in subjects vaccinated at the site: “As of now, we know that it is safe.
On July 4, Krishna Ella, PhD, chairman & managing director of Bharat, told India’s Financial Express that he was confident that the company will grow and carry COVAXIN to patients in 2021: “You can be absolutely confident.” Definitely, you will have a vaccine from us, that’s for sure.”