During November 2012-July 2013, a marked increase of adenovirus type 7 (Ad7) infections associated with severe disease was documented among pediatric patients in Singapore. Phylogenetic analysis ...revealed close genetic links with severe Ad7 outbreaks in China, Taiwan, and other parts of Asia.
Introduction
Epidemiological modeling is widely used to offer insights into the COVID-19 pandemic situation in Asia. We reviewed published computational (mathematical/simulation) models conducted in ...Asia that assessed impacts of pharmacological and non-pharmacological interventions against COVID-19 and their implications for vaccination strategy.
Methods
A search of the PubMed database for peer-reviewed, published, and accessible articles in English was performed up to November 2022 to capture studies in Asian populations based on computational modeling of outcomes in the COVID-19 pandemic. Extracted data included model type (mechanistic compartmental/agent-based, statistical, both), intervention type (pharmacological, non-pharmacological), and procedures for parameterizing age. Findings are summarized with descriptive statistics and discussed in terms of the evolving COVID-19 situation.
Results
The literature search identified 378 results, of which 59 met criteria for data extraction. China, Japan, and South Korea accounted for approximately half of studies, with fewer from South and South-East Asia. Mechanistic models were most common, either compartmental (61.0%), agent-based (1.7%), or combination (18.6%) models. Statistical modeling was applied less frequently (11.9%). Pharmacological interventions were examined in 59.3% of studies, and most considered vaccination, except one study of an antiviral treatment. Non-pharmacological interventions were also considered in 84.7% of studies. Infection, hospitalization, and mortality were outcomes in 91.5%, 30.5%, and 30.5% of studies, respectively. Approximately a third of studies accounted for age, including 10 that also examined mortality. Four of these studies emphasized benefits in terms of mortality from prioritizing older adults for vaccination under conditions of a limited supply; however, one study noted potential benefits to infection rates from early vaccination of younger adults. Few studies (5.1%) considered the impact of vaccination among children.
Conclusion
Early in the COVID-19 pandemic, non-pharmacological interventions helped to mitigate the health burden of COVID-19; however, modeling indicates that high population coverage of effective vaccines will complement and reduce reliance on such interventions. Thus, increasing and maintaining immunity levels in populations through regular booster shots, particularly among at-risk and vulnerable groups, including older adults, might help to protect public health. Future modeling efforts should consider new vaccines and alternative therapies alongside an evolving virus in populations with varied vaccination histories.
Introduction: We tested the total spike antibody (S-Ab), IgG/IgM S-Ab, and neutralizing antibody (N-Ab) responses of COVID-19-naïve subjects from before their first BNT162b2 vaccination up to 210 ...days after boosting. Methods: We studied 136 COVID-19-naïve subjects who received three doses of the Pfizer mRNA vaccine (39 males, 97 females, mean age 43.8 ± 13.5 years) from January 2021 to May 2022. Serum was assessed for total S-Ab (Roche), IgG/M (Abbott), and N-Ab (Snibe). Results: Peak antibody levels were measured 20-30 days after each dose, with booster dosing eliciting significantly higher peak antibodies than the second dose: total S-Ab 2219 vs. 19,551 BAU/mL (difference 16,667 BAU/mL, p < 0.0001); IgG 2270 vs. 2932 BAU/mL (difference 660 BAU/mL, p = 0.04); and N-Ab 3.52 vs. 26.4 µg/mL (difference 21.4 µg/mL, p < 0.0001). Only IgM showed a lower peak post-booster antibody titer (COI 2.11 vs. 0.23, difference 1.63, 95% CI 1.05 to 2.38, p < 0.0001). By 180−210 days after the second or third vaccination, total S-Ab/IgG/N-Ab had decreased by 68.7/93.8/73.6% vs. 82.8/86.3/79.5%. The half-lives of IgG and N-Ab antibodies were longer after the third vaccination (IgG: 65 vs. 34 days, N-Ab: 99 vs. 78 days). Conclusion: Total S-Ab/IgG/N-Ab showed a greater increase post-booster, with IgG/N-Ab having a longer half-life.
The primary objective of this study was to validate a novel method of assessing hand hygiene compliance using ultrasound transmitters in patient zones and staff tagged with receivers. The secondary ...objective was to assess the impact of audio reminders and quantified individual feedback.
An observational comparison against manual assessment followed by assessment using an open-label randomized control method.
Patient zones were established in 3 wards of 2 large teaching hospitals, including 88 general and 18 intensive care unit ward beds.
Consented regular ward nursing, medical, and allied health staff.
Concordance between 40 hours of manual observation using trained hand hygiene auditors and automated measures of opportunities and compliance. Subsequent measured interventions were reminder beeps and written individual feedback.
When compared with manual observations, ultrasound monitoring underestimated percentage compliances by a nonsignificant mean (95% confidence interval CI) difference of 5.2% (-20.1% to 9.8%; Formula: see text). After the intervention, adjusted multivariate analysis showed mean (95% CI) overall compliance in the intervention arm was 6.8% (2.5%-11.1%; Formula: see text) higher than in the control arm. Results stratified by compliance at entry and exit showed that the effect of intervention was stronger for compliance at exit than at entry.
Our automated measure of hand hygiene compliance is valid when compared with the traditional gold standard of manual observations. As an interventional tool, ultrasound-based automated hand hygiene audits have significant benefit that can be built upon with enhancements and find increasing acceptance with time.
We documented the total spike antibody (S-Ab), IgG S-Ab and neutralizing antibody (N-Ab) responses of BNT162b2/CoronaVac vaccinees up to 90 days post-booster dose.
We included 32 homologous regimen ...CoronaVac vaccinees and 136 BNT162b2 mRNA vaccinees. We tested their total S-Ab (Roche), IgG (Abbott) and N-Ab (Snibe) levels at set time points from January 2021 to April 2022. All subjects were deemed to be COVID-19-naïve either via clinical history (CoronaVac vaccinees) or nucleocapsid antibody testing (BNT162b2 vaccinees).
All antibodies peaked 20-30 days post-inoculation. In BNT162b2 vaccinees, all post-booster antibodies were significantly higher than second-dose peaks. In CoronaVac vaccinees, IgG showed no significant differences between peak third-/second-dose titers (difference of 56.0 BAU/mL, 95% CI of -17.1 to 129,
= 0.0894). The post-vaccination titers of all antibodies in BNT162b2 vaccinees were significantly higher than those in CoronaVac vaccinees at all time points. Post-booster, all antibodies declined in 90 days; the final total/IgG/N-Ab titers were 7536 BAU/mL, 1276 BAU/mL and 12.5 μg/mL in BNT162b2 vaccinees and 646 BAU/mL, 62.4 BAU/mL and 0.44 μg/mL in CoronaVac vaccinees.
The mRNA vaccine generated more robust total S-Ab, IgG and N-Ab responses after the second and third vaccinations.
Introduction: We compared the early total spike antibody (S-Ab) and neutralizing antibody (N-Ab) responses to two vaccines. Methods: We studied 96 Pfizer and 34 Sinovac vaccinees over a 14-month ...period from January 2021 to February 2022. All vaccinees received three doses of one type of vaccine. Antibody levels (Roche Elecsys total S-Ab and the Snibe N-Ab) were tested 10 days after the first dose, 20 days after the second dose, and 20 days after the booster dose. Results: At all time points, the mRNA vaccine generated higher S-Ab and N-Ab responses than the inactivated virus vaccine (S-Ab: first dose 2.48 vs. 0.4 BAU/mL, second dose 2174 vs. 98 BAU/mL, third dose 15,004 vs. 525 BAU/mL; N-Ab: first dose 0.05 vs. 0.02 µg/mL, second dose 3.48 vs. 0.38 µg/mL, third dose 19.8 vs. 0.89 µg/mL). mRNA vaccine recipients had a 6.2/22.2/28.6-fold higher S-Ab and 2.5/9.2/22.2-fold higher N-Ab response than inactivated virus vaccine recipients after the first/second/third inoculations, respectively. Mann–Whitney U analysis confirmed the significant difference in S-Ab and N-Ab titers between vaccination groups at each time point. Conclusions: The mRNA vaccines generated a more robust S-Ab and N-Ab response than the inactivated virus vaccine at all time points after the first, second, and third vaccinations.
Neurologic complications have long been associated with influenza. A novel strain of influenza A (H1N1) first described in humans to have outbreak potential in 2009 in Mexico went on to become the ...first influenza pandemic of this century. We evaluated the neurologic complications of the novel influenza A (H1N1) 2009 in children and adults admitted to all public hospitals in Singapore during the influenza A (H1N1) 2009 pandemic between May 2009 and March 2010. All patients were positive for novel H1N1 infection and presented with neurologic symptoms prior to oseltamivir treatment. Ninety-eight patients (median age 6.6 years, range 0.4–62.6) were identified; 90 % were younger than 18 years; 32 % suffered from preexisting neurological, respiratory, or cardiac disease; and 66 % presented with seizures. Of those presenting with seizures, new onset seizures were the most common manifestation (
n
= 40, 61.5 %), followed by breakthrough seizures (
n
= 18, 27.7 %) and status epilepticus (
n
= 7, 10.8 %). Influenza-associated encephalopathy occurred in 20 %. The majority of children (
n
= 88) presented with seizures (
n
= 63, 71.6 %), encephalopathy (
n
= 19, 21.6 %), and syncope (n = 4, 4.5 %). Among adults, a wider range of neurological conditions were seen, with half of them presenting with an exacerbation of their underlying neurological disease. The neurological symptoms developed at a median of 2 days after the onset of systemic symptoms. The median length of hospital stay was 3 days, and 79 % were monitored in general wards. Neurologic complications associated with the novel influenza A (H1N1) 2009 strain were generally mild and had a good outcome. They occurred more frequently in patients with underlying neurological disorders. Seizures and encephalopathy were the most common manifestations, similar to other influenza virus strains.
A novel Hendra‐like paramyxovirus named Nipah virus (NiV) was the cause of an outbreak among workers from one abattoir who had contact with pigs. Two patients had only respiratory symptoms, while 9 ...patients had encephalitis, 7 of whom are described in this report. Neurological involvement was diverse and multifocal, including aseptic meningitis, diffuse encephalitis, and focal brainstem involvement. Cerebellar signs were relatively common. Magnetic resonance imaging scans of the brain showed scattered lesions. IgM antibodies against Hendra virus (HeV) were present in the serum of all patients. Two patients recovered completely. Five had residual deficits 8 weeks later.
Chikungunya infections were detected in Singapore among returning travelers who had visited friends and relatives (VFR) in India and Malaysia. These sporadic imported cases occurred over a year ...before the 2008 chikungunya outbreaks in Singapore, demonstrating the potential for introducing this emerging viral infection into new areas via VFR travel.
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