Effectiveness of primary series and booster vaccination against SARS-CoV-2 infection and hospitalisation among adolescents aged 12-17 years in Singapore: a national cohort study.

BACKGROUND: Singapore offered the BNT162b2 vaccine (tozinameran; Pfizer-BioNTech) to adolescents aged 12-17 years in May 18, 2021, and extended booster vaccines to this group in Jan 21, 2022. Literature on the effectiveness of primary series and booster vaccination among adolescents is scarce outside of Europe and North America. We aimed to determine primary series and booster vaccine effectiveness against SARS-CoV-2 infection and hospitalisation among adolescents in Singapore. METHODS: For this national cohort study, we assessed the incidence of confirmed SARS-CoV-2 infection and hospitalisation among adolescents aged 12-17 years vaccinated with BNT162b2 in Singapore from Sept 1 to Dec 15, 2021, during the delta (B.1.617.2) variant wave, and from Jan 21 to April 28, 2022, during the omicron (B.1.1.529) variant wave. Data were collected from official databases maintained by the Ministry of Health of Singapore. Individuals were classified as partly vaccinated (those who had received one dose and those who had received the second dose no more than 7 days previously), fully vaccinated (8 days after receiving a second dose), or boosted (8 days after receiving a third dose) and compared with unvaccinated individuals. FINDINGS: 249 763 individuals aged 12-17 years were included in the study, contributing over 56·2 million person-days of observation. Compared with unvaccinated individuals, two vaccine doses achieved vaccine effectiveness of 66% (95% CI 63-69) against infection with the delta variant and 25% (21-29) against infection with the omicron variant, and 83% (74-89) against delta variant-associated hospitalisation and 75% (56-86) against omicron variant-associated hospitalisation. Booster vaccination with a third dose achieved vaccine effectiveness of 56% (53-58) against infection with the omicron variant and 94% (86-97) against omicron-associated hospitalisation, compared with unvaccinated adolescents. Vaccine effectiveness against infection for both variants after two doses waned over time, whereas vaccine effectiveness against hospitalisation for both variants remained stable; both were increased after three doses. INTERPRETATION: Among adolescents aged 12-17 years, vaccine effectiveness against confirmed SARS-CoV-2 infection after two doses of BNT162b2 decreased over time and increased after a third dose. Boosted adolescents were also the most protected from hospitalisation compared with fully vaccinated, partly vaccinated, and unvaccinated adolescents. Therefore, the booster dose of BNT162b2 can help to reduce the burden on the health-care system and individual morbidity during an omicron wave. FUNDING: None.

Comparative Effectiveness of mRNA and Inactivated Whole-Virus Vaccines Against Coronavirus Disease 2019 Infection and Severe Disease in Singapore.

Compared with individuals vaccinated with Pfizer-BioNTech/Comirnaty, recipients of Sinovac-CoronaVac and Sinopharm were 2.37 (95% CI, 2.29-2.46) and 1.62 (95% CI, 1.43-1.85) times more likely to be infected with coronavirus disease 19, respectively, while individuals vaccinated with Moderna were 0.42 (95% CI, 0.25-0.70) times less likely to develop severe disease.

Diabetes distress and peripheral neuropathy are associated with medication non-adherence in individuals with type 2 diabetes in primary care.

BACKGROUND: Psychosocial factors like diabetes distress and social support, as well as the presence of complications, affect an individual's self-management ability; however, their role in adherence behaviours is not yet clear. We examined the role of psychosocial factors and complications in non-adherence behaviours in individuals with diabetes in primary care. METHODS: Baseline survey with nine-month follow up through medical records of patients with type 2 diabetes attending primary care. Medication adherence and diabetes distress were assessed using Morisky Green Levine Medication Adherence Scale and Problem Areas in Diabetes, respectively. Appointment adherence was assessed through medical records. RESULTS: Of the 448 participants studied, 59.8% had medication non-adherence and 21.7% were non-adherent to scheduled appointments. PAID score (odds ratio (OR) 1.01, 95% confidence interval 1.00-1.03, p = 0.013), peripheral neuropathy (OR 1.99, 95%CI 1.18-3.37, p = 0.01), home glucose monitoring (OR 0.46, 95%CI 0.30-0.69, p < 0.001), HbA1c (OR 1.34, 95%CI 1.13-1.61, p = 0.001), and age (OR 0.96, 95%CI 0.93-0.98, p = 0.001) were associated with medication non-adherence. Indian ethnicity (OR 2.93, 95%CI 1.59-5.39, p = 0.001), secondary or higher education (OR 1.94, 95%CI 1.14-3.27, p = 0.014), and HbA1c (OR 1.38, 95%CI 1.18-1.63, p < 0.001) were associated with appointment non-adherence. CONCLUSIONS: Non-adherence behaviours were prevalent and significantly associated with higher HbA1c. Medication non-adherence was more likely in younger individuals, those with higher diabetes distress or peripheral neuropathy. Appointment non-adherence was more likely in individuals of Indian ethnicity or those with higher education. Greater support for these groups may help improve adherence behaviours and outcomes.

The 2016 Singapore Zika virus outbreak did not cause a surge in Guillain-Barré syndrome.

Although individuals with Zika virus (ZIKV) antibodies were reported in Malaya in mid-1950s, entomological and human surveillance in Singapore did not identify autochthonous transmission until the outbreak of August-November, 2016. A total of 455 cases from 15 separate clusters were identified. We asked if this ZIKV outbreak increased the incidence of Guillain-Barré syndrome (GBS) and aimed to characterize these cases. Eleven GBS cases, consecutively enrolled into our prospective GBS database from onset to 4 weeks after outbreak, and six controls, comprising three GBS patients enrolled before outbreak and three non-GBS patients, were examined for evidence of recent ZIKV infection. We performed serum, urine ZIKV RT-PCR, ZIKV serology, and virus neutralization assays, accounting for cross-reaction and co-infection with dengue (DENV). We found five GBS cases with only serological evidence of recent ZIKV infection (including one ZIKV-DENV co-infection). A temporal relationship with ZIKV outbreak was unlikely as two cases were GBS controls enrolled 3 months before outbreak. None reported symptoms of ZIKV infection. In addition, compared to last 10 years the national number of GBS hospitalizations did not increase during and immediately after outbreak. We conclude the 2016 Singapore ZIKV outbreak did not cause a change in GBS epidemiology.