The government has authorised Biological E's Corbevax as a prophylactic dosage for persons over the age of 18 who have been completely vaccinated with either Covishield or Covaxin, according to official sources, news agency PTI reported.
This is the first time in the country that a booster dosage different from the one used for initial immunisation against Covid has been permitted.
According to reports, the Union Health Ministry's clearance is based on recent recommendations from the COVID-19 Working Group of the National Technical Advisory Group on Immunisation (NTAGI).
"Corbevax will be considered as a precaution dose after completion of six months or 26 weeks from the date of administration of the second dose of either Covaxin or Covishield vaccines for those aged above 18 years enabling use of Corbevax as a heterologous COVID-19 vaccine for precaution dose administration in this age group," the sources were quoted by PTI in its report.
According to the sources, this will be in addition to the existing rules for homologous prophylactic dosage delivery of Covaxin and Covishield vaccine.
All essential adjustments to the administration of the Corbevax vaccination precaution dosage are being made through the Co-WIN interface.
Corbevax, India's first indigenously manufactured RBD protein subunit vaccine, is now being used to immunise children aged 12 to 14 years as part of the COVID-19 immunisation programme.
In its July 20 meeting, the COVID-19 Working Group (CWG) reviewed data from a double-blind randomised phase-3 clinical study that assessed the immunogenicity and safety of a booster dose of Corbevax vaccine when administered to COVID-19-negative adult volunteers aged 18-80 years who had previously received two doses of either Covishield or Covaxin.
"Following the examination of the data, the CWG observed that Corbevax vaccine can induce significant increase in antibody titers when given to those who have received either Covaxin or Covishield, which is likely to be protective as per the neutralisation data also," the sources said.
On June 4, the Drugs Controller General of India (DCGI) authorised Corbevax as a prophylactic dosage for those aged 18 and over.
From January 10, India began providing vaccine precaution doses to healthcare and frontline workers, as well as individuals aged 60 and older with comorbidities.
From March 16, the country began immunising youngsters aged 12 to 14, and it also abolished the comorbidity clause, making all adults over the age of 60 eligible for the precaution dosage of Covid vaccine.
On April 10, India began giving COVID-19 vaccination prophylactic doses to all adults over the age of 18.
Union Health Secretary Rajesh Bhushan said in a letter dated August 8, 2022 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 vaccine for people aged more than 18 years. This enables the use of Corbevax as a heterologous Covid-19 vaccine for the administration of precaution dose in this age group, he further wrote.
The letter states that there will be no change in existing guidelines for homologous precaution dose administration of Covaxin and Covishield vaccines.
Bhushan also wrote that the option of a heterologous precaution dose with Corbevax would be available to all persons above 18 years of age, in addition to the existing homologous precaution dose.
According to the letter, all necessary changes with regard to the administration of a heterologous precaution dose using Corbevax, for the persons who are eligible and due for their precaution dose, have been made on the Co-WIN portal. The provision will become live from August 12, 2022.