Covishield’s immune response same as UK version of Oxford-AZ jab: Study
New Delhi: Covishield, the locally manufactured version of Oxford-AstraZeneca (AZD1222) vaccine against Coronavirus disease (Covid-19), has similar immune response as compared to AZD1222, and acceptable safety profile, according to the bridging phase 2/3 trial carried out in India. The trial’s results are part of a pre-print study yet to be peer reviewed.
Covishield (SII-ChAdOx1 nCoV-19), locally manufactured by Pune based Serum Institute of India (SII) following technology transfer from AstraZeneca, was evaluated in a phase 2/3 immuno-bridging study in India.
“SII-ChAdOx1 nCoV-19 has a non-inferior immune response compared to AZD1222 and an acceptable safety/reactogenicity profile,” said the the phase 2/3, Observer-Blind, Randomised, Controlled Study.
The Oxford-AstraZeneca vaccine is sold as Vaxzevria in Western markets.
Between August 25 and October 31, 2020, 1601 participants were enrolled for the study, of which 401 were in the immunogenicity or reactogenicity cohort and 1200 in the safety cohort.
“After two doses of SII-ChAdOx1 nCoV-19 or AZD1222, seroconversion rates for anti-spike IgG antibodies were 98% and 98·9%, respectively…,” said researchers.
Drugs Controller General of India (DCGI) granted emergency use authorization to Covishield on January 3, this year, after the national drugs regulator’s subject expert committee recommended its approval.
As per Union health ministry’s provisional data till 7pm on Monday, 697 million doses of the vaccine have so far been administered.
SII submitted the drugs regulator safety, immunogenicity and efficacy data generated on 23,745 participants aged 18 years and older from overseas clinical studies.
The overall efficacy of this recombinant chimpanzee adenovirus vector anti Covid-19 vaccine was found to be 70.42%.
The company also submitted data from the bridging trials to the national drugs regulator that was not made public then.
“Further, M/s Serum was granted permission to conduct Phase-II/III clinical trial on 1600 participants within the country. The firm also submitted the interim safety and immunogenicity data generated from this trial and the data was found comparable with the data from the overseas clinical studies. After detailed deliberations Subject Expert Committee has recommended for the grant of permission for restricted use in emergency situation subject to certain regulatory conditions,” the drugs controller said in a statement while approving Covishield for emergency use in India.
A senior public health expert said on condition of anonymity that while “the results have been on the expected lines” the question was “why it took so long to put out results considering they did submit interim data with the drugs regulator for review during the EUA process.”
There was no response from the SII on the issue.
Meanwhile, commenting on the issue of counterfeit Covishield vaccine doses in circulation in the South East Asia and Africa region of WHO (World Health Organisation), the Union health ministry issued certain identifying markers for those administering Covid-19 vaccine doses on ground, to authenticate the supply.
“…it was requested that the vaccines need to be carefully authenticated before use… the information on genuine Covid-19 vaccine labels and additional information of the Covid-19 vaccine in use is being enclosed for reference of programme managers and service providers under the National Covid-19 vaccination programme,” it said in a letter to state governments.
For Covishield, the advisory says, “…The lettering is printed in special white ink to be more clear and readable. The general trend is to keep white lettering in reverse and just print the solid color. This gives the labels a special look and unique claret and readability. The entire label has been given a special texture honeycomb effect which is visible only at a specific angle…”
For Covaxin, the ministry mentioned that vaccinators should look for an invisible UV helix (DNA like structure) on label that is only visible under UV light; micro text hidden in label claim dots that is written as Covaxin; green foil effect in the ‘x’ of Covaxin; and holographic effect on Covaxin.
For the third vaccine that is being administered under the programme, the Russian made Sputnik V, the ministry clarified that imported products are from two different bulk manufacturing sites from Russian and, hence, there are two different labels for both these sites.
While all the information and design is same, only manufacturer name is different in the pack. For all the imported products till now, the English label is only available on the front and back of the carton of 5 ampoule pack. All other sides including primary label on the ampoule is in Russian.
The letter also has scanned pictures of all three vaccine packs for reference.
“The service providers and monitoring teams for Covid-19 vaccination may be informed about these details and to ensure due diligence towards recognition of counterfeit vaccines,” the health ministry’s letter said.