China's CoronaVac vaccine safe and effective in children above 3 years: Study
The study covers the data from early-stage trials of the vaccine that were conducted on 550 young people.
Chinese COVID-19 vaccine CoronaVac has been found to be safe and effective for use in children as young as three years old, as per a new study published in The Lancet Infectious Diseases Journal.
The study covers the data from early-stage trials of the vaccine that were conducted on 550 young people. Researchers found that the vaccine is safe and provokes a strong antibody response among children and adolescents aged between 3-17 years.
The CoronaVac vaccine, manufactured by Sinovac, had gained emergency use approval from the World Health Organization for use among adults earlier this month. It has also already been approved for emergency use for children above three years old and teenagers in China. The authorities have though not announced an immunisation schedule for these groups.
The Study: Key Highlights
• The authors of the study conducted a randomised and controlled phase 1/2 clinical trial between October and December 2020 covering 550 young people aged between 3-17 years.
• All the children were given varying vaccine doses of different strength (1.5 or 3 micrograms) through an intramuscular injection to test immune response and side effects.
• In the Phase 1 trial, all the participants in both the 1.5-microgram and 3-microgram groups generated antibodies, while stronger responses were detected among the 3-microgram group.
• In phase 2 trials, 97 percent of the participants in the 1.5-microgram group produced antibodies against SARS-CoV-2, compared with 100 percent in the 3-microgram group.
• Most of the adverse reactions were reported to be mild or moderate, with pain at the injection site the most commonly reported symptom.
• Based on the results, the authors of the study recommend the use of two 3 microgram doses of the vaccine for children and adolescents aged between 3-17 years.
Sinovac's Qiang Gao was quoted saying: “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 immunisation strategies involving children and adolescents.”
He stated that "children and adolescents with Covid-19 usually have mild or asymptomatic infections compared with adults; however, a small number may still be at risk of severe illness and they can also transmit the virus to others, making it vital to test the safety and effectiveness of Covid-19 vaccines in younger age groups."
Why is this significant?
As per leading experts, the move to vaccinate the younger population will help better control and reduce the transmission rate and protect the adolescents from severe infection and long Covid. It would also lessen the need to roll out booster shots.
Further, the children must be vaccinated in all populations to ensure herd immunity is reached against the new and emerging Covid variants. Experts say that herd immunity against Covid-19 is the prerequisite to end this pandemic, either through vaccinations or natural infection.
Limitations of the study
The authors acknowledged that there are some limitations to their study, as T-cell responses that are responsible for seeking out and killing infected cells were not assessed.
Sinovac is in the process of applying for an ethical review and approval for late-stage clinical trials for the younger population.
The US, France and Israel have already started administering the Pfizer vaccine for children aged over 12 years. The health officials in the United Kingdom, however, are awaiting further data on the safety profile of the vaccine and rates of post-Covid syndromes in adolescents.