Beijing:
Two doses of the China-made COVID-19 vaccine, CoronaVac, are protected and generate a robust antibody response amongst children and adolescents aged 3-17 years, according to a study published in The Lancet Infectious Diseases journal.
The phase 1/2 trial on 550 young persons located that more than 96 per cent of children and adolescents who received two doses of the vaccine, manufactured by Sinovac, created antibodies against SARS-CoV-2, the virus that causes COVID-19.
Most adverse reactions have been mild or moderate, with discomfort at the injection web page the most usually reported symptom, the researchers stated.
“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,” stated Qiang Gao from Sinovac Life Sciences, China.
“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,” Gao stated.
The researchers carried out the phase 1/2 clinical trial of CoronaVac in wholesome children and adolescents aged 3-17 years in Zanhuang County, China.
Between October 31 and December 2, 2020, 72 participants have been enrolled in phase 1, and 480 participants enrolled in phase 2 involving December 12 and December 30, 2020.
The vaccine — either 1.5 microgram ( g) or 3 g per dose — or a manage was provided by intramuscular injection in two doses, at day and day 28.
Among the 550 participants who received at least one dose of vaccine or the manage, adverse reactions inside 28 days occurred in 56 (26 per cent) of 219 participants in the 1.5 g group.
Such adverse events have been reported in 63 (29 per cent) of 217 participants in the 3 g group, and 27 (24 per cent) of 114 in the manage group.
Only one significant adverse reaction — a case of pneumonia — was reported in the manage group, on the other hand, this was unrelated to the COVID-19 vaccination, the researchers stated.
In phase 1, one hundred per cent of participants in each the 1.5 g and 3 g groups generated antibodies against SARS-CoV-2.
Stronger immune responses — determined by the quantity of antibodies made that can neutralise the virus — have been detected amongst the 3 g group compared with the 1.5 g group.
In phase 2, 97 per cent of participants in the 1.5 g group made antibodies against SARS-CoV-2, compared with one hundred per cent in the 3 g group.
Participants in the 3 g group once more made a stronger immune response than these in the 1.5 g group.
The researchers noted that immune responses amongst children and adolescents have been larger than these measured in adults aged 18-59 years and elderly aged 60 years and older.
No important variations in immune response have been detected in an evaluation by age group.
More than 93 per cent of these in the 1.5 g and 3 g groups aged 3-5 years, 6-11 years, and 12-17 years made antibodies against SARS-CoV-2 at day 28 just after the second dose.
The researchers advise two 3 g doses of the vaccine for children and adolescents aged 3-17 years based on their benefits.
They acknowledged some limitations in their study.
T cell responses — which play an vital function in SARS-CoV-2 infections — have been not assessed in the study, even though these have been investigated in connected research.
The study involved a smaller quantity of participants and all have been of Han ethnicity, highlighting a have to have for bigger research in other regions and involving multi-ethnic populations.
The researchers noted that extended-term security and immune response information have been not out there, even though participants will be followed for at least one year.
They stated the benefits must be interpreted with caution as it was not probable to draw robust statistical conclusions owing to the smaller quantity of participants in the study.
“Herd immunity against COVID-19 is the prerequisite to end this pandemic, either through vaccinations or natural infection, said Professor Bin Cao, of the China-Japan Friendship Hospital, who was not involved in the study.
Cao noted that most estimates placed the threshold at 65-70 per cent of the population gaining immunity, mainly by vaccination.
“However, broadly circulating virus variants and persistent hesitancy on vaccine make this threshold tricky to attain. Thus, the calculation has to be revised upward and children need to be covered in the immunisation campaign,” he added.
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