Two doses of CoronaVac are safe and produce a strong antibody response among children and adolescents aged 3-17 years.

CoronaVac is a Covid-19 vaccine manufactured by the Chinese firm Sinovac.

The results of the Phase 1/2 clinical trial of the vaccine are published in The Lancet Infectious Diseases journal.

China earlier this month, authorized the emergency use of CoronaVac, for children aged between 3 and 17 years.

In a randomized controlled trial of 550 young people, more than 96 per cent children and adolescents developed antibodies against SARS-CoV-2, the virus causing Covid-19.

Most adverse reactions were mild or moderate, with pain at the injection site the most commonly reported symptom.

“Our finding that CoronaVac was well tolerated and induced strong immune responses is very encouraging, and suggests that further studies in other regions, involving larger, multi-ethnic populations, could provide valuable data to inform immunization strategies involving children and adolescents,” said Qiang Gao, of Sinovac Life Sciences Co, China.

The team conducted a randomized, double-blind, controlled phase 1/2 clinical trial of CoronaVac in 550 healthy children and adolescents aged 3-17 years in Zanhuang County, China between October 31 and December 30.

The vaccine (either 1.5 or 3 microgram per dose) or control was given by intramuscular injection in two doses, at day 0 and day 28.

Among the 550 participants who received at least one dose of vaccine or the control, adverse reactions mostly mild or moderate, with pain at the injection site occurred within 28 days in 13 per cent, 73/550 participants.

However, one limitation in the study is that T cell responses — which play an important role in SARS-CoV-2 infections — were not assessed in the study, said the researchers.

In India, the Pune-based Serum Institute of India (SII) will begin clinical trials of Novavax for children starting July.

Hyderabad-based Bharat Biotech has also two vaccines that are being tried on children, Covaxin and BBV154, a one-shot nasal vaccine.

ZyCov-D, the Zydus’ Covid-19 vaccine has trials on children in the age group 12-18 years was found effective.

US pharma major Pfizer has also announced that its vaccine is safe for children above 12 years of age.