The Subject Expert Committee (SEC) under the Central Drugs Standard Control Organisation (CDSCO), on June 22, approved the Phase-3 trial efficacy data of Bharat Biotech’s COVID-19 vaccine, Covaxin.
The data shows 77.8 percent efficacy, CNBC-TV18 reported.
The Phase 3 trials were conducted on 25,800 volunteers. Bharat Biotech has submitted the data earlier this week.
Covaxin, the country’s first indigenous COVID-19 vaccine, was developed with seed strains received from the National Institute of Virology (NIV), using the Whole Virion Inactivated Vero Cell-derived platform technology.
Efficacy
In April, Bharat Biotech announced that Covaxin has 78 percent efficacy, based on the interim data of 127 symptomatic COVID-19 cases from participants in the Phase-3 trials. The company said the vaccine has demonstrated 100 per cent efficacy against severe cases in Phase 3 trials. As part of the study, Bharat Biotech has enrolled 25,800 volunteers in the age bracket of 18-98 years.
How does Covaxin compare with other COVID-19 vaccines?
If Covaxin has shown 77.8 percent efficacy in the final analysis, its efficacy is decent. The main competitor of Covaxin in India is Covishield (AstraZeneca-Oxford COVID-19 vaccine). Its overall efficacy against symptomatic COVID-19 cases -- after more than 14 days and 2 doses -- is 76 percent. Vaccine efficacy in volunteers, who took the first and second doses in an interval of 12 weeks and above, is 81.3 percent. Covishield is approved by the WHO.
The data of the Sputnik V vaccine indicates that it has 91.6 percent efficacy. Sputnik V is yet to be approved by the WHO for emergency listing. The mRNA vaccines of Pfizer and Moderna have 95 percent and 94 percent efficacy, respectively, after the second dose. Pfizer’s vaccine requires a storage temperature of -70 degrees Centigrade.
Johnson & Johnson’s single dose COVID-19 vaccine, approved by the WHO, has shown 66 percent protection against moderate to severe COVID infections. The two Chinese vaccines listed for emergency use by WHO -- Sinopharm and Sinovac -- have an efficacy rate of 79 percent and 54 percent, respectively, as per interim results.
How is Covaxin working against the Delta variant?
The other interesting aspect to know about Covaxin is its efficacy against variants of concern (VoC), especially the Delta variant, which has now emerged dominant. The recent Phase-3 efficacy data published by Novavax protein subunit vaccines has tried to map the vaccine efficacy on VoCs.
They have sequenced the clinical trial subjects who have tested positive to see how the vaccine is faring against the variants. Except for AstraZeneca’s vaccine (Covishield) and Pfizer’s, we don't have much data on how efficacious these vaccines are against the Delta variant. Most COVID-19 vaccines’ efficacy dropped against the Delta variant.
Speeding up WHO emergency listing
The Phase-3 efficacy data will boost Covaxin’s chances of getting WHO emergency use listing, which will be critical for the global acceptance of the indigenous COVID-19 jab.
The pre-submission meeting for Covaxin is scheduled for June 23 (tomorrow). The WHO has accepted the Expression of Interest (EoI) for Covaxin. The global body has sought more information from the Indian company. The pre-submission meeting will be followed by the acceptance of the dossier for review, following which WHO gives a targeted action date or anticipated decision date. According to the WHO, only COVID-19 vaccines that have undergone phase IIb or phase III studies and have been submitted to the NRA (National Regulatory Agency) of record, are under consideration.
WHO decision on listing will not be made until the NRA of record has authorised the vaccine.
Full approval
With Phase-3 efficacy data in place, Covaxin will be eligible to get full marketing authorisation. Currently, the vaccine is approved under emergency use authorisation. Well, this doesn't materially change anything for the company but full approval will enhance confidence on the vaccine.