The COVID vaccine developed by China's Sinopharm Group is highly effective in combating the novel coronavirus, says a study conducted by a leading university in Sri Lanka.

According to the findings of researchers from Sri Jayewardenepura University, or SJU, around 95 percent of the recipients of the China-made vaccine had developed antibodies against SARS-CoV-2, the virus that causes the COVID-19 respiratory illness.

More significantly, the study revealed that the Sinopharm jab is also "very effective" against the super-contagious Delta variant, or B.1.617.2, which has spread to 92 countries worldwide.

The findings will put Sinopharm among the world's best vaccines to fight the dreaded disease.

"The antibody responses to Delta variant, and neutralizing antibodies, were similar to levels seen following natural infection," Neelika Malavige, head of the immunology and molecular sciences department at SJU.

The outcome of the study will certainly put to rest the doubts persistently raised against the efficacy of the Sinopharm vaccine, Malavige told China Daily from Colombo.

"Although I have not made any head-head-to-head comparison, it appears that Sinopharm is as good as the world's most effective vaccines," said the professor, who co-headed the study.

The research findings were uploaded on the university website on July 20.

China has so far donated 7.1 million doses of Sinopharm vaccines — including a batch of 2 million doses shipped on July 11 — to Sri Lanka, which has a population of some 22 million.

Chandima Jeewandara, director of allergy immunology and cell biology department at SJU, noted the high transmissibility of the Delta variant that has hit so many countries across the world.

The Delta strain, which is also known as B.1.617.2 and is said to have first surfaced in India in December 2020, is reportedly responsible for a bulk of the new infections in many parts of the world now.

Sinopharm vaccine was found to work well in the immune system T Cells, one of two primary types of lymphocytes, according to Malavige.

The conclusion was drawn after the researchers had analysed anti-body functions, she said, adding that the findings will go a long way in allaying fears about the efficacy of the Chinese vaccine.

"About 95 percent of individuals who received both doses of the vaccine developed antibodies," Malavige said.

"The response to the vaccine was better in people aged between 20 and 39 years," she said. According to her, around 98 percent of people in the 20-39 age group developed antibodies compared to 93 percent in people aged 60 years and above.

Malavige added that the antibody responses to variants like Delta were similar to those observed after natural COVID-19 infection.

Funded by the World Health Organization, UK Medical Research Council, Britain's Foreign and Commonwealth Office, and the Chinese Academy of Medical Sciences' Innovation Fund for Medical Science, the Sri Lankan study was conducted among 282 men and women divided into three age groups. The research team included scientists and researchers from the University of Oxford.

Malavige noted that there had been "considerable amount of apprehension about the efficacy of Sinopharm" vaccine earlier, "largely because we did not have sufficient data".

"That must go now," she said.

According to her, people aged between 20 and 39 had very high seroconversion rates (98.9 percent), while the seroconversion rates in individuals aged 60 years and above were somewhat lower (93.3 percent).

Seroconversion is a gauge of development of specific antibodies in the blood serum in the wake of infection or immunization.

The antibody levels to Delta and Beta strains were similar to levels following natural infection although the antibody levels were lower for Alpha, according to the findings.

The writer is a freelance journalist for China Daily.