More granular data on Covid-19 cases among children under 18 should be released to boost people's confidence and allay fears over the adolescent vaccination programme.
Molecular virologist Dr Vinod Balasubramaniam, a senior lecturer in microbiology at the Jeffrey Cheah School of Medicine and Health Sciences of Monash University Malaysia, urged the Health Ministry to be more transparent with daily Covid-19 data, especially genomic surveillance data on children below 18.
He said this includes details on Covid-19 infections, mortality rate and hospitalisation with severe symptoms to determine whether the Delta variant was the major driving force in the spread of infections in this age group.
"Concern is mounting as the number of children below 18 years old getting infected with Covid-19 is surging, with parents especially worried because schools are due to reopen.
"There seems to be a pattern of increased hospitalisation, severe Covid-19 symptoms and fatalities with the Delta strain circulating, compared with cases last year, when there were fewer reports of variants of concern.
"Children below 18 are part of the vulnerable group who are currently not vaccinated or have lower vaccination coverage.
"With the highly transmissible Delta strain becoming the predominant one behind the surges in infections in the past couple of months in Malaysia, this (surge in teenage infections) is expected," he told the New Sunday Times.
Covid-19 infections among children in Malaysia spiked to more than 300,000 cases up to the end of August, which is 25 times more than the total cases last year.
A total of 67 children have died of Covid-19 this year, compared with just six last year.
Vinod said a similar trend could be seen in the United States, with two studies finding that Covid-19 cases among children and adolescents have been rising as the Delta variant became more dominant.
He said studies from the US Centers for Disease Control and Prevention (CDC) showed that adolescent Covid-19 hospitalisation rates were the highest among those who were unvaccinated and in communities with low vaccine coverage.
"Both studies in the Morbidity and Mortality Report looked at Covid-19 among children and adolescents age zero to 17 years and compared data from July and August when the highly transmissible Delta variant was dominant to earlier periods in the pandemic.
"A study of national data on Covid-19 cases among children and adolescents in 2021 found that they peaked in January, dropped in June and spiked in August. The weekly Covid-19 hospitalisation rate follows a similar pattern.
"During the week ending Aug 14, about 1.4 out of every 100,000 children and adolescents were hospitalised for Covid-19, nearly five times the weekly rate in late June and close to the peak in January, according to another study of 14 states."
He said this strengthened the need for this age group to be vaccinated immediately.
"The Covid-19 pandemic is already the pandemic of the unvaccinated. The virus is tracking the unvaccinated.
"The growing number of children hospitalised with Covid-19 could further strain the already overburdened paediatric healthcare system in Malaysia."
Vinod said data showed that children, particularly adolescents, could play a significant part in Covid-19 transmission and concerns were growing as new variants emerge.
He said more transmissible variants might develop a way to push through a young person's immune response to make them less resistant to infection, making it important that they were vaccinated.
He said research showed that the Pfizer-BioNTech Covid-19 vaccine was 100 per cent effective in preventing infection in children age 12 to 15 and 91 per cent effective in preventing severe illness in people aged 16 and older.
"Even before getting the US' FDA emergency use authorisation, clinical trials showed Covid-19 vaccines to be remarkably safe and effective for adults and teens age 12 and up," he said, referring to the US Food and Drug Administration.
"Trials involved tens of thousands of volunteers. The vaccines continue to be monitored very closely. In fact, the CDC says that Covid-19 vaccines will have 'the most intensive safety monitoring in US history'."
He said while a small number of adolescents and young adults experienced mild cases of heart inflammation (myocarditis) after being getting Covid-19 jabs, most recovered on their own or with minimal treatment and rest.
But research showed that unvaccinated children were 37 times more likely to develop myocarditis when infected by Covid-19, he added.
"Apart from that, we are also exposing children to higher risks such as long-term Covid infection and the multisystem inflammatory syndrome in children if they are not vaccinated. So the benefit of vaccination clearly outweighs any other concern."