ALLOWING THE mix and match of Covid vaccines for the first time, the Centre on Wednesday approved Hyderabad-based Biological E’s protein sub-unit vaccine, Corbevax, as a “heterologous” booster in adults.
This means that those who have received Covishield or Covaxin as their first or second dose can take Corbevax as the third booster shot, officials said. According to the protocol until now, the third dose had to be the same vaccine that was used for the first and second doses.
The latest decision comes almost two months after India’s drug regulator approved Corbevax as a heterologous Covid booster dose for individuals aged 18 years. The approval was based on clinical trial data that showed “significant enhancement” in immune response and “excellent safety profile” required for an effective booster.
On Wednesday, Union Health Secretary Rajesh Bhushan informed states that Corbevax will be available as a “precaution dose” after the completion of six months or 26 weeks from the date of administration of the second dose of either Covaxin or Covishield for the adult population.
Bhushan also conveyed that the availability of Corbevax as a “precaution dose” would go live on the CoWIN platform from August 12.
Corbevax is India’s first indigenously developed Receptor Binding Domain (RBD) protein sub-unit vaccine against Covid, with two doses scheduled 28 days apart. It can be stored at 2-8 degrees Celsius, which is best suited for India’s requirements.
Instead of using the whole virus, a traditional sub-unit vaccine platform triggers an immune response by using fragments. Corbevax contains the harmless S-protein. Once the human immune system recognises the protein, it produces antibodies as white blood cells to fight the infection.
Corbevax includes an antigen developed by Texas Children’s Hospital Centre for Vaccine Development and licensed from BCM Ventures, which is Baylor College of Medicine’s integrated commercialisation team.
The Centre has already made an advance payment of Rs 1,500 crore to reserve 30 crore doses of this vaccine.
At present, Corbevax is being used in India for children aged 12-14 years, with 3.96 crore first doses and 2.89 crore second doses administered.