Impact of Omicron variant sublineage BA.2.75 on the OnSite COVID-19 Ag Rapid Test: the applicability of rapid antigen test with universal transport media.

BACKGROUND: Rapid antigen testing (RAT) is one of the most powerful tools for SARS-CoV-2 detection. The OnSite COVID-19 Ag Rapid Test is an antigen-based, point-of-care test approved by the WHO for Emergency Use Listing. The Nucleocapsid (N) gene mutations found in the emerging Omicron sublineages lead to the question of RAT performance. OBJECTIVE: To ensure the diagnostic performance of the study RAT during rapidly mutated Omicron variants. RESULTS: We independently evaluated the performance of this assay in 1098 archived samples collected in Thailand during October 2022-February 2023, which were 798 and 300 COVID-19 real-time RT-PCR positive and negative, respectively. The assay performed with 100% sensitivity and 100% specificity using a cycle threshold (Ct) of <20 for the RT-PCR. The sensitivity decreased to 88% when using Ct <30. Most of the SARS-CoV-2 found were Omicron BA.2 (99%), harboring six known N mutations (P13L, E31del, S33del, R203K, G204R and S413R). Eight samples containing hybrid variants (XBB.1*, XBB.2 and XBJ) were detected by the study RAT. This RAT detects all Omicron sublineages known to be circulating in Thailand. CONCLUSIONS: These results confirmed the good performance of the study RAT for detecting Omicron variants and its appropriateness for individual diagnosis and for genomic surveillance.

Assessment of safety and intranasal neutralizing antibodies of HPMC-based human anti-SARS-CoV-2 IgG1 nasal spray in healthy volunteers.

An HPMC-based nasal spray solution containing human IgG1 antibodies against SARS-CoV-2 (nasal antibody spray or NAS) was developed to strengthen COVID-19 management. NAS exhibited potent broadly neutralizing activities against SARS-CoV-2 with PVNT50 values ranging from 0.0035 to 3.1997 µg/ml for the following variants of concern (ranked from lowest to highest): Alpha, Beta, Gamma, ancestral, Delta, Omicron BA.1, BA.2, BA.4/5, and BA.2.75. Biocompatibility assessment showed no potential biological risks. Intranasal NAS administration in rats showed no circulatory presence of human IgG1 anti-SARS-CoV-2 antibodies within 120 h. A double-blind, randomized, placebo-controlled trial (NCT05358873) was conducted on 36 healthy volunteers who received either NAS or a normal saline nasal spray. Safety of the thrice-daily intranasal administration for 7 days was assessed using nasal sinuscopy, adverse event recording, and self-reporting questionnaires. NAS was well tolerated, with no significant adverse effects during the 14 days of the study. The SARS-CoV-2 neutralizing antibodies were detected based on the signal inhibition percent (SIP) in nasal fluids pre- and post-administration using a SARS-CoV-2 surrogate virus neutralization test. SIP values in nasal fluids collected immediately or 6 h after NAS application were significantly increased from baseline for all three variants tested, including ancestral, Delta, and Omicron BA.2. In conclusion, NAS was safe for intranasal use in humans to increase neutralizing antibodies in nasal fluids that lasted at least 6 h.

Does prior vaccination affect the immune response to seasonal influenza vaccination among older adults? Findings from a prospective cohort study in a Northeastern Province of Thailand.

BACKGROUND: We measured the immunogenicity of seasonal trivalent inactivated influenza vaccines (IIV3) among older Thai adults and the effect of one-year prior vaccination status on immune responses. METHOD: Adults aged ≥65 years (n = 370) were vaccinated with Southern Hemisphere IIV3 in 2015. Hemagglutination inhibition assays were performed using goose red blood cells on sera collected from the participants at baseline and after 1, 6, and 12 months of vaccination. Prior year vaccination (in 2014) was verified with the national health security office database. We analyzed the associations between prior vaccination and geometric mean titers (GMT) at each time point using generalized linear regression on logged transformed titers, and seroprotection and seroconversion using Log-binomial regression. RESULTS: At baseline, previously vaccinated participants (n = 203) had a significantly higher GMT and seroprotection against all three influenza strains than those previously unvaccinated (n = 167) (all p-values <0.001). Seroprotection rates were similar after one month in both groups for A(H1N1)pdm09 (adjusted risk ratio [aRR] 1.10, 95% CI 0.97-1.25), and A(H3N2) (aRR 1.08, 95% CI 0.87-1.33), but higher in previously vaccinated persons for B (aRR 1.20, 95% CI 1.08-1.32). At 12 months, 50% or more had seroprotection in previously vaccinated group with no difference between previously vaccinated or unvaccinated persons. Seroconversion was lower in the previously vaccinated group for A(H1N1)pdm09 (aRR 0.62, 95% CI 0.43-0.89), but did not differ between the two groups for A(H3N2) (aRR 0.94, 95% CI 0.69-1.28) and B (aRR 0.85, 95% CI 0.60-1.20). CONCLUSION: Influenza vaccination elicited good humoral response in older Thai adults. While seroconversion seemed attenuated in persons previously vaccinated for influenza A(H1N1)pdm09 (the only vaccine strain not to change), this was not apparent for influenza A(H3N2) and B, and prior vaccination was not associated with any inhibition in seroprotection.

SARS-CoV-2 Seroprevalence in Unvaccinated Adults in Thailand in November 2021.

Between the first case of COVID-19 in January 2020 and the end of 2021, Thailand experienced four waves of the epidemic. The third and fourth waves were caused by the alpha and delta strains from April 2021 to November 2021. Serosurveillance studies provide snapshots of the true scale of the outbreak, including the asymptomatic infections that could not be fully captured by a hospital-based case detection system. We aimed to investigate the distribution of SARs-CoV-2 seroprevalence in unvaccinated adults after the delta wave outbreak. From November to December 2021, we conducted a cross-sectional survey study in 12 public health areas (PHAs) across Thailand. A total of 26,717 blood samples were collected and tested for SARs-CoV-2 antibodies (anti-S IgG) using a qualitative immunoassay. The results showed that seropositive prevalence in this cohort was 1.4% (95% CI: 1.24 to 1.52). The lowest prevalence was in the northern region (PHA 1) and in central Thailand (PHA 3) at 0.4% (95% CI: 0.15 to 0.95), while the highest was in the southern region of Thailand (PHA 12) at 5.8% (95% CI: 4.48 to 7.29). This seropositive prevalence was strikingly lower than the reports from other countries. Our serosurveillance results suggest that the vaccination of unvaccinated groups should be accelerated, especially in the public health areas with the lowest seroprevalence.

Predictors of seasonal influenza vaccination among older adults in Thailand.

BACKGROUND: In advance of a large influenza vaccine effectiveness (VE) cohort study among older adults in Thailand, we conducted a population-based, cross-sectional survey to measure vaccine coverage and identify factors associated with influenza vaccination among older Thai adults that could bias measures of vaccine effectiveness. METHOD: We selected adults ≥65 years using a two-stage, stratified, cluster sampling design. Functional status was assessed using the 10-point Vulnerable Elders Survey (VES); scores ≥3 indicated vulnerability. Questions about attitudes towards vaccination were based on the Health Belief Model. The distance between participants' households and the nearest vaccination clinic was calculated. Vaccination status was determined using national influenza vaccination registry. Prevalence ratios (PR) and 95% confidence intervals (CIs) were calculated using log-binomial multivariable models accounting for the sampling design. RESULT: We enrolled 581 participants, of whom 60% were female, median age was 72 years, 41% had at least one chronic underlying illness, 24% met the criteria for vulnerable, and 23% did not leave the house on a daily basis. Influenza vaccination rate was 34%. In multivariable models, no variable related to functional status was associated with vaccination. The strongest predictors of vaccination were distance to the nearest vaccination center (PR 3.0, 95% CI 1.7-5.1 for participants in the closest quartile compared to the furthest), and high levels of a perception of benefits of influenza vaccination (PR 2.8, 95% CI 1.4-5.6) and cues to action (PR 2.7, 95% CI 1.5-5.1). CONCLUSION: Distance to vaccination clinics should be considered in analyses of influenza VE studies in Thailand. Strategies that emphasize benefits of vaccination and encourage physicians to recommend annual influenza vaccination could improve influenza vaccine uptake among older Thai adults. Outreach to more distant and less mobile older adults may also be required to improve influenza vaccination coverage.

Achieving universal health coverage goals in Thailand: the vital role of strategic purchasing.

Strategic purchasing is one of the key policy instruments to achieve the universal health coverage (UHC) goals of improved and equitable access and financial risk protection. Given favourable outcomes of Universal Coverage Scheme (UCS), this study synthesized strategic purchasing experiences in the National Health Security Office (NHSO) responsible for the UCS in contributing to achieving UHC goals. The UCS applied the purchaser-provider split concept where NHSO, as a purchaser, is in a good position to enforce accountability by public and private providers to the UCS beneficiaries, through active purchasing. A comprehensive benefit package resulted in high level of financial risk protection as reflected by low incidence of catastrophic health spending and impoverished households. The NHSO contracted the District Health System (DHS) network, to provide outpatient, health promotion and disease prevention services to the whole district population, based on an annual age-adjusted capitation payment. In most cases, the DHS was the only provider in a district without competitors. Geographical monopoly hampered the NHSO to introduce a competitive contractual agreement, but a durable, mutually dependent relationship based on trust was gradually evolved, while accreditation is an important channel for quality improvement. Strategic purchasing services from DHS achieved a pro-poor utilization due to geographical proximity, where travel time and costs were minimal. Inpatient services paid by Diagnostic Related Group within a global budget ceiling, which is estimated based on unit costs, admission rates and admission profiles, contained cost effectively. To prevent potential under-provisions of the services, some high cost interventions were unbundled from closed end payment and paid on an agreed fee schedule. Executing monopsonistic purchasing power by NHSO brought down price of services given assured quality. Cost saving resulted in more patients served within a finite annual budget.

Community participation of cross-border migrants for primary health care in Thailand.

This is the first report of the large-scale utilization of migrants as health volunteers in a migrant primary-healthcare program. The program recruited migrants who volunteered to serve their communities. This study explores the identities of these volunteers, their relationship with program management, and their attitudes. The study also investigates the impact of the volunteers, from the migrants' and healthcare workers' perspective. The study was conducted in two provinces, Tak (northern Thailand) and Samut Sakhon (central Thailand). Primary and secondary information was collected. Mixed methods, comprising in-depth interviews, observation and questionnaires, were used to gather primary data from three groups of participants-migrant volunteers, migrants and healthcare workers. Secondary data, and in-depth interviews with healthcare workers, showed that migrant volunteers made a significant contribution to the provision of both preventive and curative services. The quantitative study covered 260 migrant volunteers and 446 migrants. The results found that <5% of volunteers were selected by the community. Almost all attended a training course. Most were assigned to be health communicators; four stated they did nothing. Volunteers' attitudes were very positive. Most migrants reported that the volunteers' work was useful. It was concluded that the migrant health-volunteer program did help deal with migrant health problems. However, management of the program should be closely considered for more effective outcomes.

Trends and inequities in where women delivered their babies in 25 low-income countries: evidence from Demographic and Health Surveys.

In low-income countries, the coverage of institutional births is low. Using data from the two most recent Demographic and Health Surveys (1995-2001 and 2001-2006) for 25 low-income countries, this study examined trends in where women delivered their babies--public or private facilities or non-institutional settings. More than half of deliveries were in institutional settings in ten countries, mostly public facilities. In the other 15 countries, the majority of births were in women's homes, which was often their only option. Between the two survey periods, all five Asian countries studied (except Bangladesh) had an increase of 10-20 percentage points in institutional coverage, whereas none of the 19 sub-Saharan African countries saw an increase of more than 10 percentage points. More urban women and more in the richest (least poor) quintile gave birth in public or private facilities than rural and poorest quintile women. The rich-poor gap of institutional births was wider than the urban-rural gap. Inadequate public investment in health system infrastructure in rural areas and lack of skilled health professionals are major obstacles in reducing maternal mortality. Governments in low-income countries must invest more, especially in rural maternity services. Strengthening private, for-profit providers is not a policy choice for poor, rural communities.

Equity of access to and utilization of reproductive health services in Thailand: national Reproductive Health Survey data, 2006 and 2009.

This study assessed trends in equity of access to reproductive health services and service utilization in terms of coverage of family planning, antenatal care and skilled birth attendance in Thailand. Two health indicators were measured: the prevalence of low birthweight and exclusive breastfeeding. Equity was measured against the combined urban-rural areas and geographic regions, women's education level and quintiles of household assets index. The study used data from two nationally representative household surveys, the 2006 and 2009 Reproductive Health Surveys. Very high coverage of family planning (79.6%), universal antenatal care (98.9%) and skilled birth attendance (99.7%), with very small socioeconomic and geographic disparities, were observed. The public sector played a dominant role in maternity care (90.9% of all deliveries in 2009). The private sector also had a role among the higher educated, wealthier women living in urban areas. Public sector facilities, followed by drug stores, were a major supplier of contraception, which had a high use rate. High coverage and low inequity were the result of extensive investment in the health system by successive governments, in particular primary health care at district and sub-district levels, reaching universality by 2002. While maintaining these achievements, methodological improvements in measuring low birthweight and exclusive breastfeeding for future reproductive health surveys are recommended.

Deployment of early diagnosis and mefloquine-artesunate treatment of falciparum malaria in Thailand: the Tak Malaria Initiative.

BACKGROUND: Early diagnosis and treatment with artesunate-mefloquine combination therapy (MAS) have reduced the transmission of falciparum malaria dramatically and halted the progression of mefloquine resistance in camps for displaced persons along the Thai-Burmese border, an area of low and seasonal transmission of multidrug-resistant Plasmodium falciparum. We extended the same combination drug strategy to all other communities (estimated population 450,000) living in five border districts of Tak province in northwestern Thailand. METHODS AND FINDINGS: Existing health structures were reinforced. Village volunteers were trained to use rapid diagnostic tests and to treat positive cases with MAS. Cases of malaria, hospitalizations, and malaria-related deaths were recorded in the 6 y before, during, and after the Tak Malaria Initiative (TMI) intervention. Cross-sectional surveys were conducted before and during the TMI period. P. falciparum malaria cases fell by 34% (95% confidence interval [CI], 33.5-34.4) and hospitalisations for falciparum malaria fell by 39% (95% CI, 37.0-39.9) during the TMI period, while hospitalisations for P. vivax malaria remained constant. There were 32 deaths attributed to malaria during, and 22 after the TMI, a 51.5% (95% CI, 39.0-63.9) reduction compared to the average of the previous 3 y. Cross-sectional surveys indicated that P. vivax had become the predominant species in Thai villages, but not in populations living on the Myanmar side of the border. In the displaced persons population, where the original deployment took place 7 y before the TMI, the transmission of P. falciparum continued to be suppressed, the incidence of falciparum malaria remained low, and the in vivo efficacy of the 3-d MAS remained high. CONCLUSIONS: In the remote malarious north western border area of Thailand, the early detection of malaria by trained village volunteers, using rapid diagnostic tests and treatment with mefloquine-artesunate was feasible and reduced the morbidity and mortality of multidrug-resistant P. falciparum.