In light of the two death cases of young children contracted with COVID-19 during the fifth outbreak in Hong Kong, I went through some relevant research findings and hopefully, we could have better understanding of the situation.

According to Harwood et al (2022), hospitalized infants and teenagers were the most vulnerable; some more risk factors were identified: obesity, heart and neurological problems might contribute to the severity of the disease. Moreover, in Hong Kong, Prof Lau Yu-lung suggested that babies were less exposed to other human coronavirus these days; as a result, SARS-CoV-2 could cause more severe diseases because of the lack of immunological memory. Parents should take care of their babies and teenage sweethearts and be alert if there are any symptoms; prompt medical treatment should be initiated before the situation requires hospitalization.

Based on another study, Pietrasanta et al (2022) reported that the protective antibodies against SARS-CoV-2 could be transferred from mothers to foetuses during pregnancy. In other words, the foetus could benefit form mother’s immunity; with this logic, many experts, including those from the Johns Hopkins University, believed that it was important for pregnant women to get vaccinated. Nevertheless, some risks had been discussed by Yang et al (2021): the risk factors included hypertension, obesity, and diabetes. Pregnant women should consider getting vaccinated if their physical condition is good.

Finally, is it safe and effective for children younger than 5 years of age to get vaccinated? The clinical trial of CoronaVac reported that the vaccine was safe and effective for antibody production among children and teenagers from 3 to 17 years of age. Pfizer and BioNTech are conducting some clinical trials among children from 6 months to 4 years of age. The trial is still underway; it is anticipated that we could see the data by April 2022. For the time being, children older than 3 could consider CoronaVac.