By Dr Anu Suria Ganason, Dr Yafizah Yahaya and Dr Fathima Begum Syed Mohideen

Malaysia is in the midst of the third wave of exponentially increasing COVID-19, which is threatening and can affect our health care system in various ways. In addition, the COVID-19 infection affecting the paediatric group, that is children, and the adolescent group is likewise alarming. Given that due to lockdown, the children and adolescents also face the consequence of missing out on their formal education, social interaction, and activities in school and institutions. This illustrates that they are also an important group for vaccination.

In Malaysia, the data from January to June 29, 2021, shows that 116,378 people under the age of 18 tested positive for COVID-19. This accounts for about 15.3% of the total cases. There were 28,912 cases with ages ranging from 0 to 4 years, 12,055 cases with ages ranging from 5 to 6 years, 38,206 cases from 7 to 12 years, and 37,205 cases among those aged 13 to 17 years. Malaysia also recorded the deaths of three children under the age of 5 and 27 adolescents under the age of 19 in the intensive care unit.

As a result, our government is on the verge of speeding up the vaccination process to ensure that 80% of the population will be vaccinated to achieve herd immunity. By Aug 23, 2021, 56.9% of the adult population had been fully vaccinated under the current third phase of the vaccination programme. When the vaccination process is completed in 65% of the adult population, the next phase will include the adolescents from the age group of 12 to 18 years, which is planned by mid-September. The Centre for Disease Control and Prevention recommends that adolescents over the age of 12 should be vaccinated.

Children, adolescents and COVID-19 infection

Children under the age of 12 years are believed to be less likely to contract COVID-19. Children also have milder symptoms compared to adolescents and adults. The expression of the primary target receptor for SARS-CoV-2, that is the angiotensin-converting enzyme-2 (ACE-2), which is low in younger age groups, could be one explanation.

Moreover, adults are prone to severe COVID-19 infection due to high and persistent viral loads, compared to children. Furthermore, children who have had a past infection with one of the other four variant types may develop cross-protection against a subsequent infection.

However, the emergence of rapidly spreading variants suggest children and adolescents might be contributing to the spread of the virus as they can be a carrier of the virus in the community.

Studies on COVID-19 vaccination for those between the ages of 6 months to 17 years are still ongoing. There are few theories about vaccinating children. Children’s immune systems are brimmed with cells that have not been exposed much to pathogens, so they tend to produce a robust immune response to vaccines. This is evident from a trial that showed adolescents aged 12 to 15 years, who received two doses of Pfizer BioNTech, developed an essentially higher level of virus-blocking antibodies compared to those aged 16 to 25 years. Hence, studies are currently in progress whether children could receive a lower dose of the vaccine than the expected current doses.

Moreover, a trial of Pfizer BioNTech on adolescents showed 18 cases of COVID-19 positive in the placebo group and none infected in the vaccinated group. Therefore, the same efficacy would be expected in younger children. Moreover, experts want to ensure that COVID-19 vaccination does not interfere with the routine immunisation for children.

Another problem is that children have a strong immune response and are therefore more likely to develop a fever after vaccination. Therefore, it is important to consider fever as a major side effect of vaccination. Treatment plans to minimise side effects while triggering a strong immune response will be a consideration.

Safety of the vaccine in the children and adolescent groups

The safety of the vaccine is of paramount importance in clinical trials in children. Vaccine-induced myocarditis and pericarditis were observed in those below the age of 30 following Pfizer BioNTech vaccination (Prevention, 2020). However, the reported cases are extremely rare. The case was reported among males in the first few weeks after the second-dose vaccination. There were no serious vaccine-related side effects or deaths reported. Only mild to moderate side effects were reported, including pain at the injection site, fatigue, headache, chills, fever and body ache. Therefore, it is crucial to know that the benefit of vaccination outweighs the risks.

In addition, before the administration of the first dose of vaccine, the medical officer will interview the vaccinees for any medical problem that hinders them from vaccination. After this assessment, the parents or the caregiver has to give a written consent to proceed with vaccination. However, those with medical problems, like uncontrolled asthma, will be referred to the hospital for a pre-vaccination assessment while those who are already on hospital follow-up due to medical problems will be informed by the hospital of the eligibility for vaccination.

In Malaysia, the number of COVID-19 vaccines available has increased to five. These are Pfizer BioNTech, Sinovac, Oxford-AstraZeneca, Janssen and CanSinoBio. In general, all vaccines are approved as safe and effective with rare side effects.

In the United States, only Pfizer BioNTech is recommended for children 12 years and older whereas in China, the Sinovac vaccine is considered safe from the age of 3 to 17. Vaccines are still being tested for children under the age of 12.

However, in Malaysia, only the Pfizer-BioNTech vaccine is approved for the use of adolescents 12 years and older.

In summary, we hope to receive positive results from the vaccination programme in terms of efficacy, safety and immunogenicity and to promote vaccination in all children over 12 years of age. In the future, children under the age of 12 should also be vaccinated.

-- BERNAMA

Dr Anu Suria Ganason, Dr Yafizah Yahaya, Dr Fathima Begum Syed Mohideen are with the Faculty of Medicine and Health Sciences, Universiti Sains Islam Malaysia.