Studies show that Pfizer's and AstraZeneca's Covid vaccines are highly effective against Delta variant, while tests show Chinese shots less effective on Delta variant.
Antibodies triggered by two Chinese COVID-19 vaccines are less effective against the Delta variant compared with other strains but the shots still offer protection, a Chinese disease control researcher told state media.
The Delta variant of the new coronavirus, first detected in India, is becoming the globally dominant variant of the disease with its increased transmissibility, the World Health Organization's chief scientist warned last week.
In an interview aired by China Central Television late on Thursday, Feng Zijian, researcher and former deputy director at the Chinese Center for Disease Control and Prevention, did not provide further details.
Pfizer says COVID vaccine is highly effective against Delta variant
The Pfizer-BioNTech (PFE.N) vaccine is highly effective against the Delta variant of COVID-19, a Pfizer official in Israel said on Thursday.
First identified in India, Delta is becoming the globally dominant variant of the coronavirus, according to the World Health Organization.
"The data we have today, accumulating from research we are conducting at the lab and including data from those places where the Indian variant, Delta, has replaced the British variant as the common variant, point to our vaccine being very effective, around 90%, in preventing the coronavirus disease, COVID-19," Alon Rappaport, Pfizer's medical director in Israel, told local broadcaster Army Radio.
A study by researchers from the University of Texas together with Pfizer and BioNtech and published this month by Nature journal found that antibodies elicited by the vaccine were still able to neutralize all tested variants, including Delta, albeit at reduced strength.
Other recent studies have also shown the vaccine is likely to provide high protection against the variant.
An analysis by Public Health England (PHE), where the Delta variant is more widespread, found that both the Pfizer/BioNTech and AstraZeneca (AZN.L) vaccines provide more than 90% protection against hospitalization from the Delta variant.