Faced with the threat of new variants causing Covid-19, not only adults but also children are the target groups that need to be vaccinated to ensure vaccine coverage in the community.
But the issue of vaccinating children is still a big challenge and there have been a series of questions raised, such as, which vaccines should children get? If injected, what are the effects of the vaccine?
In Singapore, even with more than 80% of the population being vaccinated, there are still about half a million children under the age of 12 who are unvaccinated. Last week, Singapore’s Health Minister Ong Ye Kung said elderly and immunocompromised people would receive booster shots. According to the official, the vaccination program for children under 12 years old is expected to start in early 2022 after completing the trials and getting official approval.
In the US, children accounted for nearly a quarter of cases recorded in the week to August 26. That number has grown exponentially, at levels not seen since the winter of 2020, said the American Academy of Pediatrics.
Why is it taking so long to develop a vaccine for children?
Hundreds of millions of adults around the world have been vaccinated against Covid-19 and the results show that they are very safe and effective in fighting the disease. But these results are not a substitute for studies that need to be done in children.
From the increasing number of children hospitalized to the long-term illness of many children, health officials say that children are increasingly being affected more seriously by the Covid-19 epidemic. To prepare a vaccine for children, scientists will use both the results of the adult trials and the results of the children’s trials.
Stanley Perlman, a professor of microbiology and immunology at the University of Iowa School of Medicine (USA), explains that for children under 12 years of age, companies do not need to fully select 30,000 children to participate in the trial, because they can perform on even adults. The data show that this age group also has the same immune response as adults.
Vaccine companies share this approach. But at the beginning of August, the FDA required monitoring data on the safety of the vaccine for children for up to 6 months, while in adults it only needed 2 months. The agency also asked Pfizer and Moderna to double the number of children ages 5 to 11 participating in clinical trials.
In June, CDC vaccine advisers said there was a potential link between the mRNA vaccine and rare cases of myocarditis in adolescents, but the benefits of vaccination still outweigh the risks. than the risk it poses. Most cases of myocarditis are mild and can be resolved on their own or with only a few days of treatment. At Texas Children’s Hospital, US, pediatrician James Versalovic said, they had no trouble finding children to participate in the trial because the list of children registered was very long. However, the expansion of the trial extended the research process by another month.
“We all think it’s worth doing to get more convincing data and give parents more peace of mind when getting their children vaccinated,” said James Versalovic.
When is testing complete?
The first vaccine approved for use in children could be Pfizer-BioNTech’s Covid-19 vaccine, as the two companies’ trials are expected to be completed ahead of the others. A Pfizer-BioNTech spokesperson said that data from the clinical trial on 2,250 children aged 5 to 11 years old will be available by the end of September. Next, the two companies will apply for a license from the US Food and Drug Administration (FDA) in October 2021.
Although Pfizer-BioNTech has extended the registration of the vaccine trial to another 2,250 children, this should not delay the release of data from the original cohort of children.
“The trial expansion will help the two companies gather more data to accurately assess the safety and effectiveness of the vaccine in children,” Pfizer said. It is expected that the full data set from the vaccine study in children will be published later this year.
Moderna said in August 2021 that it hoped to collect enough data by the end of the year to apply for a vaccine for children aged 6 to 11 years old. Currently, Moderna’s vaccine is only approved for use in people 18 years of age and older. The company also applied for an emergency use authorization from the FDA for adolescents aged 12 to 17 in June 2021.
Meanwhile, China’s Sinovac Group also announced the results of the first phase of testing a vaccine against Covid-19 for children aged 3 to 17 years old.
Associate Professor Hsu Li Yang of the National University of Singapore (NUS) said that, if all goes according to plan, the FDA will grant emergency use of the Pfizer-BioNTech vaccine for children under 12 years old before the end of this year. . Like previous times, the Health Sciences Authority of Singapore (HSA) can then authorize the emergency use of the vaccine.
The US approved the emergency use of the Pfizer-BioNTech vaccine for emergency use to people 16 years of age and older on December 11, 2020. Three days later, the HSA took the same step.
How are vaccines for children different?
Professor Dale Fisher, senior consultant at the Department of Infectious Diseases of the National University Hospital Singapore (NUH), said that the vaccine for children will have a smaller dose than for adults.
The dose for children 5 to 11 years old is 1/3 of the adult dose. The dose for children under 5 years old is 1/10 of the adult dose. Dosage is based on studies of vaccine safety and efficacy in early-stage trials with these age groups.
Clinical trial information published online shows that the Pfizer-BioNTech vaccine in doses ranging from 10mg to 30mg is being tested on children of different age groups.
“Children rarely develop severe symptoms with Covid-19 but are at high risk if they have underlying medical conditions. We will learn more about the effectiveness of childhood vaccinations from available data and from abroad over the next three to six months,” said Dale Fisher.