ABSTRACT
Background: Vaccine effectiveness (VE) of BNT162b2 and CoronaVac against COVID-19-associated hospitalization and moderate-to-severe disease due to SARS-CoV-2 Omicron BA.2 for pediatric populations that had low exposure to prior SARS-CoV-2 variants needs to be further clarified. This can be studied from the 1.36 million vaccine doses had been administered to 766,601 of 953,400 children and adolescents in Hong Kong (HK) since March 2021 to April 2022. Methods: Using an ecological design leveraging the HK vaccination coverage statistics and public hospital records, this study investigated the VE for children aged 3-11 years and adolescents aged 12-18 years at the population level during the Omicron BA.2 wave from January to April 2022. Findings: VE against COVID-19-associated hospitalization for children was 65.3% for 1 dose of BNT162b2 and 13.0% and 86.1% for 1 and 2 doses of CoronaVac, respectively. For adolescents, VE against COVID-19-associated hospitalization was 60.2% and 82.4% after 1 and 2 doses of BNT162b2 and 30.8% and 90.7% after 1 and 2 doses of CoronaVac, respectively. Protection against moderate-to-severe disease for aged 3-18 was high, with VE of 93.1% and 95.8% after 2 doses of BNT162b2 and CoronaVac, respectively. No COVID-19-associated hospitalization or moderate-to-severe disease occurred for 68,565 children and adolescents who received their third dose. Estimated hospitalizations of children and adolescents averted by vaccination were 68 and 999, respectively, and were 45 and 147 for moderate-to-severe cases. Conclusions: BNT162b2 or CoronaVac provide substantial protection from COVID-19-associated hospitalization and moderate-to-severe disease due to a SARS-CoV-2 variant of concern. Funding: The Providence Foundation.
Subject(s)
COVID-19ABSTRACT
Despite concerns about the negative effects of social distancing and prolonged school closures on children’s lifestyle and physical activity (PA) during the COVID-19 pandemic, robust evidence is lacking on the impact of the COVID-19 pandemic on children’s wellbeing and daily life. This study aimed to examine changes in the PA levels, sleep patterns and screen time of school-aged children during the different phases of COVID-19 outbreak in Hong Kong using a repeated cross-sectional design. School students (Grades 1 to 12) were asked to report their daily electronic device usage and to fill in a sleep dairy recording their daily sleep and wake-up time. They were equipped with a PA monitor, Actigraph wGT3X-BT, to obtain objective data on their PA levels and sleep patterns. Students were recruited before the pandemic (Sep 2019 – Jan 2020; n=577), during school closures (Mar 2020 – Apr 2020; n=146), and after schools partially reopened (Oct 2020 – Jul 2021; n=227). Our results indicated lower PA levels, longer sleep duration, and longer screen time among participants recruited during school closures than those recruited before the COVID-19 outbreak. Primary school students were found to sleep on average for an extra hour during school closures. Our findings illustrate the impact of social distancing policies during the COVID-19 pandemic on the sleep pattern, screen time, and PA level in school-aged children in Hong Kong. Professionals should reinforce the importance of maintaining a physically active lifestyle, good sleep hygiene, and healthy use of electronic devices to parents and school-aged children during the COVID-19 Pandemic.
Subject(s)
COVID-19ABSTRACT
The SARS-CoV-2 Omicron BA.2 subvariant replaced BA.1 globally in early 2022, and caused an unprecedented tsunami of cases in Hong Kong, resulting in the collapse of elimination strategy. Vaccine effectiveness (VE) of BNT162b2 and CoronaVac against BA.2 is unclear. We utilize an ecological design incorporating population-level vaccine coverage statistics and territory-wide case-level SARS-CoV-2 infection surveillance data, and investigate the VE against infection during the Omicron BA.2 wave between January 1 to April 19, 2022, in Hong Kong for children and adolescents. We estimate VE to be 33.0% for 1 dose of BNT162b2 in children aged 5–11 and 40.8% for 2 doses of CoronaVac in children aged 3–11. We also estimate 54.9% and 86.8% VE for 2 and 3 doses of BNT162b2, and 55.0% and 92.0% VE for 2 and 3 doses of CoronaVac in adolescents aged 12–18. Our findings support preserved VE against infection by variants of concerns for children and adolescents in settings with extremely low levels of prior SARS-CoV-2 circulation.
Subject(s)
COVID-19ABSTRACT
Background The World Health Organization recommends exclusive breastfeeding (EBF) for an infant’s first six months. Therefore, various policies were implemented to support breastfeeding in Hong Kong in the past decade. Meanwhile, the COVID-19 pandemic brought new challenges and opportunities to breastfeeding practices. This study aimed to identify the associated factors of six-month EBF, and to evaluate the impact of COVID-19 on breastfeeding practice.Methods This study was conducted using a mixed-methods approach. An electronic questionnaire was distributed to members of breastfeeding or parenting groups who have had breastfeeding experience in the past 10 years. Exploratory factor analysis with principal components analysis was used to identify the factors representing breastfeeding support from family and friends. Stepwise binary logistic regression analyses with forward (conditional) selection were conducted to examine factors associated with six-month EBF both in general and during the pandemic period. A thematic analysis was conducted using both deductive and inductive approaches.Results The study included 793 participants. Giving birth in a public hospital (AOR 2.015, 95% CI 1.440 to 2.821, p < 0.001) and breastfeeding support from family and friends (AOR 1.309, 95% CI 1.102 to 1.555, p = 0.002) were significantly associated with six-month EBF even during COVID-19. Our qualitative results indicated a high prevalence of breastfeeding problems in both public and private maternity wards, suggesting that neonatal support for breastfeeding in Hong Kong were generally insufficient and ineffective.Conclusions Giving birth in a public hospital and having breastfeeding support from family and friends were associated with six-month EBF. Furthermore, COVID-19 in Hong Kong had an overall positive impact on six-month EBF. Further studies should investigate the impact of hospital practice and the COVID-19 pandemic on breastfeeding behaviours.