Evaluation of cesarean delivery rates and factors associated with cesarean delivery among women enrolled in a pregnancy cohort study at two tertiary hospitals in Thailand.

BACKGROUND: Cesarean delivery rates have increased globally resulting in a public health concern. We estimate rates of cesarean deliveries among Thai women using the World Health Organization (WHO) Robson Classification system and compare rates by Robson group to the Robson guideline for acceptable rates to identify groups that might benefit most from interventions for rate reduction. METHODS: In 2017 and 2018, we established cohorts of pregnant women aged ≥ 18 years seeking prenatal care at two tertiary Thai hospitals and followed them until 6-8 weeks postpartum. Three in-person interviews (enrollment, end of pregnancy, and postpartum) were conducted using structured questionnaires to obtain demographic characteristics, health history, and delivery information. Cesarean delivery indication was classified based on core obstetric variables (parity, previous cesarean delivery, number of fetuses, fetal presentation, gestational week, and onset of labor) assigned to 10 groups according to the Robson Classification. Logistic regression was used to identify factors associated with cesarean delivery among nulliparous women with singleton, cephalic, term pregnancies. RESULTS: Of 2,137 participants, 970 (45%) had cesarean deliveries. The median maternal age at delivery was 29 years (interquartile range, 25-35); 271 (13%) participants had existing medical conditions; and 446 (21%) had pregnancy complications. The cesarean delivery rate varied by Robson group. Multiparous women with > 1 previous uterine scar, with a single cephalic pregnancy, ≥ 37 weeks gestation (group 5) contributed the most (14%) to the overall cesarean rate, whereas those with a single pregnancy with a transverse or oblique lie, including women with previous uterine scars (group 9) contributed the least (< 1%). Factors independently associated with cesarean delivery included age ≥ 25 years, pre-pregnancy obesity, new/worsen medical condition during pregnancy, fetal distress, abnormal labor, infant size for gestational age ≥ 50th percentiles, and self-pay for delivery fees. Women with existing blood conditions were less likely to have cesarean delivery. CONCLUSIONS: Almost one in two pregnancies among women in our cohorts resulted in cesarean deliveries. Compared to WHO guidelines, cesarean delivery rates were elevated in selected Robson groups indicating that tailored interventions to minimize non-clinically indicated cesarean delivery for specific groups of pregnancies may be warranted.

Feasibility and Performance of Self-Collected Nasal Swabs for Detection of Influenza Virus, Respiratory Syncytial Virus, and Human Metapneumovirus.

BACKGROUND: We assessed performance of participant-collected midturbinate nasal swabs compared to study staff-collected midturbinate nasal swabs for the detection of respiratory viruses among pregnant women in Bangkok, Thailand. METHODS: We enrolled pregnant women aged ≥18 years and followed them throughout the 2018 influenza season. Women with acute respiratory illness self-collected midturbinate nasal swabs at home for influenza viruses, respiratory syncytial viruses (RSV), and human metapneumoviruses (hMPV) real-time RT-PCR testing and the study nurse collected a second midturbinate nasal swab during home visits. Paired specimens were processed and tested on the same day. RESULTS: The majority (109, 60%) of 182 participants were 20-30 years old. All 200 paired swabs had optimal specimen quality. The median time from symptom onsets to participant-collected swabs was 2 days and to staff-collected swabs was also 2 days. The median time interval between the 2 swabs was 2 hours. Compared to staff-collected swabs, the participant-collected swabs were 93% sensitive and 99% specific for influenza virus detection, 94% sensitive and 99% specific for RSV detection, and 100% sensitive and 100% specific for hMPV detection. CONCLUSIONS: Participant-collected midturbinate nasal swabs were a valid alternative approach for laboratory confirmation of influenza-, RSV-, and hMPV-associated illnesses among pregnant women in a community setting.

Clinical Characteristics of Patients Hospitalized with Coronavirus Disease, Thailand.

Among 11 patients in Thailand infected with severe acute respiratory syndrome coronavirus 2, we detected viral RNA in upper respiratory specimens a median of 14 days after illness onset and 9 days after fever resolution. We identified viral co-infections and an asymptomatic person with detectable virus RNA in serial tests. We describe implications for surveillance.

Efficacy and Long-Term Safety of a Dengue Vaccine in Regions of Endemic Disease.

BACKGROUND: A candidate tetravalent dengue vaccine is being assessed in three clinical trials involving more than 35,000 children between the ages of 2 and 16 years in Asian-Pacific and Latin American countries. We report the results of long-term follow-up interim analyses and integrated efficacy analyses. METHODS: We are assessing the incidence of hospitalization for virologically confirmed dengue as a surrogate safety end point during follow-up in years 3 to 6 of two phase 3 trials, CYD14 and CYD15, and a phase 2b trial, CYD23/57. We estimated vaccine efficacy using pooled data from the first 25 months of CYD14 and CYD15. RESULTS: Follow-up data were available for 10,165 of 10,275 participants (99%) in CYD14 and 19,898 of 20,869 participants (95%) in CYD15. Data were available for 3203 of the 4002 participants (80%) in the CYD23 trial included in CYD57. During year 3 in the CYD14, CYD15, and CYD57 trials combined, hospitalization for virologically confirmed dengue occurred in 65 of 22,177 participants in the vaccine group and 39 of 11,089 participants in the control group. Pooled relative risks of hospitalization for dengue were 0.84 (95% confidence interval [CI], 0.56 to 1.24) among all participants, 1.58 (95% CI, 0.83 to 3.02) among those under the age of 9 years, and 0.50 (95% CI, 0.29 to 0.86) among those 9 years of age or older. During year 3, hospitalization for severe dengue, as defined by the independent data monitoring committee criteria, occurred in 18 of 22,177 participants in the vaccine group and 6 of 11,089 participants in the control group. Pooled rates of efficacy for symptomatic dengue during the first 25 months were 60.3% (95% CI, 55.7 to 64.5) for all participants, 65.6% (95% CI, 60.7 to 69.9) for those 9 years of age or older, and 44.6% (95% CI, 31.6 to 55.0) for those younger than 9 years of age. CONCLUSIONS: Although the unexplained higher incidence of hospitalization for dengue in year 3 among children younger than 9 years of age needs to be carefully monitored during long-term follow-up, the risk among children 2 to 16 years of age was lower in the vaccine group than in the control group. (Funded by Sanofi Pasteur; ClinicalTrials.gov numbers, NCT00842530, NCT01983553, NCT01373281, and NCT01374516.).

Tolerability of trivalent inactivated influenza vaccine among pregnant women, 2015.

BACKGROUND: Thailand recommends influenza vaccination among pregnant women. We conducted a cohort study to determine if the prevalence of adverse events following immunization (AEFIs) with influenza vaccine among Thai pregnant women was similar to that often cited among healthy adults. METHODS: Women who were ≥17 gestational weeks and ≥18 years of age were recruited. Demographic and health history data were collected using structured questionnaires. Women were provided with symptom diary, ruler to measure local reaction(s), and thermometer to measure body temperature. AEFIs were defined as any new symptom/abnormality occurring within four weeks after vaccination. The diaries were abstracted for frequency, duration, and level of discomfort/inconvenience of the AEFIs. Serious adverse events (SAEs) and the likelihood of AEFIs being associated with vaccination were determined using standard definitions. RESULTS: Among 305 women enrolled between July-November 2015, median age was 29 years. Of these, 223 (73%) were in their third trimester, 271 (89%) had completed secondary school or higher, and 20 (7%) reported ≥1 pre-existing conditions. AEFIs were reported in 134 women (44%; 95% confidence interval [CI] 38-50%). Soreness at the injection site (74, 24%; CI 19-29%), general weakness (50, 16%; CI 12-21%), muscle ache (49, 16%; CI 12-21%), and headache (45, 15%; CI 1-19%) were most common. Of those with AEFIs, 120 (89%) reported symptom/abnormality occurred on day 0 or day 1 following vaccination. Ten women (7%) reported the AEFIs affected daily activities. The AEFIs generally spontaneously resolved within 24 h of onset. There were two vaccine-unrelated SAEs. Of 294 women with complete follow-up, 279 (95%) had term deliveries, 12 (4%) had preterm deliveries, and 3 (1%) had miscarriage or stillbirth. CONCLUSION: In our cohort, AEFIs with influenza vaccine occurred with similar frequency to those reported among healthy adults in other studies, and were generally mild and self-limited. No influenza vaccine-associated SAEs were identified.

The Pregnancy and Influenza Multinational Epidemiologic (PRIME) study: a prospective cohort study of the impact of influenza during pregnancy among women in middle-income countries.

BACKGROUND: The World Health Organization identifies pregnant women as at high-risk for severe influenza, but influenza vaccines are underutilized among pregnant women. Data on influenza burden during pregnancy are largely limited to high-income countries and data on the impact of influenza on birth and perinatal outcomes are scarce. METHODS/DESIGN: This prospective, longitudinal cohort study of pregnant women in middle-income countries is designed to address three primary objectives: 1) to evaluate the effect of laboratory-confirmed influenza during pregnancy on pregnancy and perinatal outcomes; 2) to estimate the incidences of all-cause acute respiratory illness and laboratory-confirmed influenza during pregnancy; and 3) to examine the clinical spectrum of illness associated with influenza viruses. Through a multi-country network approach, three sites aim to enroll cohorts of 1500-3000 pregnant women just before local influenza seasons. Women aged ≥ 18 years with expected delivery dates ≥ 8 weeks after the start of the influenza season are eligible. Women are followed throughout pregnancy through twice weekly surveillance for influenza symptoms (≥ 1 of myalgia, cough, runny nose, sore throat, or difficulty breathing) and have mid-turbinate nasal swabs collected for influenza virus testing during illness episodes. Primary outcomes include relative risk of preterm birth and mean birth weight among term singleton infants of women with and without reverse transcription polymerase chain reaction-confirmed influenza during pregnancy. Gestational age is determined by ultrasound at < 28 weeks gestation and birth weight is measured by digital scales using standardized methods. Sites are primarily urban in Bangkok, Thailand; Lima, Peru; and Nagpur, India. All sites recruit from antenatal clinics at referral hospitals and conduct surveillance using telephone calls, messaging applications, or home visits. Nasal swabs are self-collected by participants in Thailand and by study staff in Peru and India. During the first year (2017), sites enrolled participants during March-May in Peru and May-July in India and Thailand; 4779 women were enrolled. DISCUSSION: This study aims to generate evidence of the impact of influenza during pregnancy to inform decisions by Ministries of Health, healthcare providers, and pregnant women in middle-income countries about the value of influenza vaccination during pregnancy.

Workshop on use of intravenous immunoglobulin in hand, foot and mouth disease in Southeast Asia.

The South East Asia Infectious Disease Clinical Research Network convened subject matter experts at a workshop to make consensus recommendations for study design of a clinical trial for use of intravenous immunoglobulin (IVIg) in severe hand, foot and mouth disease (HFMD). HFMD is a highly contagious emerging infection among children in the region, a small proportion of whom develop neurologic and cardiopulmonary complications with high case-fatality rates. The use of IVIg for treatment of severe disease is widespread and a part of local, national, and international guidelines, but no clinical evidence warrants the use of this drug, which is expensive and has potentially serious side effects. During a 2-day workshop in March 2014, a group of HFMD experts reviewed the current evidence related to use of IVIg in HFMD and discussed potential study design, feasibility, inclusion and exclusion criteria, sample size, primary and secondary endpoints, and subsidiary studies for a randomized, placebo-controlled trial.

Infectious causes of encephalitis and meningoencephalitis in Thailand, 2003-2005.

Acute encephalitis is a severe neurologic syndrome. Determining etiology from among ≈100 possible agents is difficult. To identify infectious etiologies of encephalitis in Thailand, we conducted surveillance in 7 hospitals during July 2003-August 2005 and selected patients with acute onset of brain dysfunction with fever or hypothermia and with abnormalities seen on neuroimages or electroencephalograms or with cerebrospinal fluid pleocytosis. Blood and cerebrospinal fluid were tested for >30 pathogens. Among 149 case-patients, median age was 12 (range 0-83) years, 84 (56%) were male, and 15 (10%) died. Etiology was confirmed or probable for 54 (36%) and possible or unknown for 95 (64%). Among confirmed or probable etiologies, the leading pathogens were Japanese encephalitis virus, enteroviruses, and Orientia tsutsugamushi. No samples were positive for chikungunya, Nipah, or West Nile viruses; Bartonella henselae; or malaria parasites. Although a broad range of infectious agents was identified, the etiology of most cases remains unknown.

Clinical efficacy and safety of a novel tetravalent dengue vaccine in healthy children in Asia: a phase 3, randomised, observer-masked, placebo-controlled trial.

BACKGROUND: An estimated 100 million people have symptomatic dengue infection every year. This is the first report of a phase 3 vaccine efficacy trial of a candidate dengue vaccine. We aimed to assess the efficacy of the CYD dengue vaccine against symptomatic, virologically confirmed dengue in children. METHODS: We did an observer-masked, randomised controlled, multicentre, phase 3 trial in five countries in the Asia-Pacific region. Between June 3, and Dec 1, 2011, healthy children aged 2-14 years were randomly assigned (2:1), by computer-generated permuted blocks of six with an interactive voice or web response system, to receive three injections of a recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV), or placebo, at months 0, 6, and 12. Randomisation was stratified by age and site. Participants were followed up until month 25. Trial staff responsible for the preparation and administration of injections were unmasked to group allocation, but were not included in the follow-up of the participants; allocation was concealed from the study sponsor, investigators, and parents and guardians. Our primary objective was to assess protective efficacy against symptomatic, virologically confirmed dengue, irrespective of disease severity or serotype, that took place more than 28 days after the third injection. The primary endpoint was for the lower bound of the 95% CI of vaccine efficacy to be greater than 25%. Analysis was by intention to treat and per procotol. This trial is registered with ClinicalTrials.gov, number NCT01373281. FINDINGS: We randomly assigned 10,275 children to receive either vaccine (n=6851) or placebo (n=3424), of whom 6710 (98%) and 3350 (98%), respectively, were included in the primary analysis. 250 cases of virologically confirmed dengue took place more than 28 days after the third injection (117 [47%] in the vaccine group and 133 [53%] in the control group). The primary endpoint was achieved with 56·5% (95% CI 43·8-66·4) efficacy. We recorded 647 serious adverse events (402 [62%] in the vaccine group and 245 [38%] in the control group). 54 (1%) children in the vaccine group and 33 (1%) of those in the control group had serious adverse events that happened within 28 days of vaccination. Serious adverse events were consistent with medical disorders in this age group and were mainly infections and injuries. INTERPRETATION: Our findings show that dengue vaccine is efficacious when given as three injections at months 0, 6, and 12 to children aged 2-14 years in endemic areas in Asia, and has a good safety profile. Vaccination could reduce the incidence of symptomatic infection and hospital admission and has the potential to provide an important public health benefit. FUNDING: Sanofi Pasteur.

Risk factors and outcomes of influenza infection among children presenting with influenza-like illness.

OBJECTIVE: Limited data were available to guide management, counseling, and/or diagnostic investigation among children presenting with influenza-like illness (ILI). During a recent period of high influenza activity, we wished to determine the frequency, outcomes, and factors associated with influenza infection among children presenting with ILI. MATERIAL AND METHOD: During September and October 2010, children presenting with ILI were enrolled. Nasal swabs were sent for polymerase chain reaction (PCR) to determine the frequency and types of influenza. Information of demographic characteristics, potential risk factors, and short-term outcomes of study participants were collected. RESULTS: Among 300 enrolled subjects, influenza infections were identified in 170 (56.7%) cases; 45.7% (n = 137) were influenza A and 11% (n = 33) were influenza B. Most cases recovered uneventfully with a 3.7% (n = 11) hospitalization rate. Risks for hospitalization did not differ by infection status (2.4% vs. 5.4% between those with and without influenza infection, respectively) or types of influenza infection. Logistic regression analysis indicated that older age, having a household member with acute respiratory illness (ARI) during the previous 7 days, having an underlying co-morbidity, and a history of premature birth were associated with influenza, with adjusted odds ratios and 95% confidence intervals of 1.19 (1.087, 1.30), 3.21 (1.096, 9.424), 2.15 (1.244, 3.728), and 0.08 (0.007, 0.876), respectively. CONCLUSION: The outcomes of influenza-associated ILI were generally favourable, with no fatalities and 2.4% risk for hospitalization. Among children presenting with ILI, age, household contact with ARI, and co morbidities increased the likelihood of influenza, whereas history of premature birth was negatively associated with influenza.

Long-term immunogenicity of the SA14-14-2 Japanese encephalitis (JE) vaccine (CD.JEVAX®) booster following chimeric JE (IMOJEV®) vaccine priming in Thai children.

Japanese encephalitis (JE) is a significant public health concern in Asia, particularly in children, where vaccination plays a crucial role in prevention. In this study, we investigated the immunogenicity and safety of two different live-attenuated JE vaccines used as primary and booster doses. Fifty healthy participants aged 1-3 years, who were primed with the chimeric JE vaccine IMOJEV® a year earlier, received a booster dose of the SA14-14-2 JE vaccine CD.JEVAX®. To evaluate the immune response, JE-neutralizing antibody titers were assessed on day 0 (pre-booster), day 30, and annually from 1 to 5 years post-booster using the 50% plaque reduction neutralization test (JEPRNT50). The assessment revealed strong immunogenicity 30 d post-booster, with a geometric mean titer of 2092.4 [95% confidence interval (CI): 1473.9-2970.5] and a seroprotection rate of 100%, which gradually decreased to 97.5% at 5 years post-booster. No severe adverse events were observed. The most common reaction within 7 d of vaccination was fever (20%; 95% CI: 10.7-32.3). These results indicate that a booster dose of CD.JEVAX® elicits a strong immune response in children previously vaccinated with IMOJEV® while maintaining a good safety profile, thus supporting the interchangeability of these two live-attenuated JE vaccines. Registered at www.thaiclinicaltrials.org (TCTR ID: TCTR20221102003), our study suggests that CD.JEVAX® can be a viable option for booster vaccination in JE prevention programs, potentially enhancing vaccine flexibility and accessibility.

Influenza virus circulation and vaccine effectiveness during June 2021-May 2023 in Thailand.

Thai Ministry of Public Health recommends influenza vaccination for certain risk groups. We evaluated 2023 Southern Hemisphere influenza vaccine effectiveness against medically attended influenza using surveillance data from nine Thai hospitals and a test-negative design. During June 2022-May 2023, influenza vaccine provided moderate protection against seeking care for influenza illness (adjusted vaccine effectiveness 51%; 95% confidence interval 28-67). Understanding vaccine effectiveness can help guide future antigen selection and support clinicians to make a strong influenza vaccine recommendation to patients.

Outcomes among Thai children with risk conditions hospitalized for pneumococcal disease (invasive or non-bacteraemic pneumonia): A multi-centre, observational study.

Objective: To describe the risk condition status and clinical outcomes among Thai children hospitalized with pneumococcal disease. Methods: In this retrospective analysis, children with invasive pneumococcal disease (IPD) or x-ray-confirmed non-bacteraemic pneumococcal pneumonia (NBPP) were identified from nine hospitals in Thailand between 2010 and 2019. Data on risk factors and outcomes were extracted from medical records. Results: In total, 413 cases were identified: 319 IPD and 94 NBPP. Overall, 133 (32.2%) patients were admitted to intensive care units and 11/406 (2.7%) died. Twenty-seven percent of IPD cases had at-risk conditions and 15% had high-risk conditions. Most IPD cases (32.9%) occurred in children aged 2-4 years, and most NBPP cases (28.7%) occurred in infants aged 0-11 months. Of 51 Streptococcus pneumoniae isolates collected, 41 (80%) were pneumococcal 13-valent conjugate vaccine serotypes. Only 5.1% of children had received a pneumococcal vaccine. Conclusions: Most children with IPD and NBPP did not have high-risk or at-risk conditions, while 42% had at-risk or high-risk conditions for pneumococcal disease. Very few children in the cohort had received any type of pneumococcal vaccine. Increasing the availability of pneumococcal conjugate vaccines should be considered to reduce the burden of pneumococcal disease among children in Thailand.

Long-term immunogenicity assessment of a DTaP-IPV//PRP-T vaccine given at 2, 4, 6 and 18-19 months of age, and immunogenicity and safety of a DTaP-IPV vaccine given as a booster dose at 4 to 6 years of age in Thai children.

Booster vaccination of infants aims to further reduce the burden of childhood infectious diseases. This study assessed the antibody persistence induced by a primary series vaccination at 2, 4, 6 months of age and a first booster at 18-19 months of age with a pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b combined vaccine (DTaP-IPV//PRP-T) in 4-6 year-old Thai children (N=123). The safety and immunogenicity of a tetravalent acellular pertussis combined vaccine (containing the same DTaP-IPV antigens as the previous vaccine) given as a second booster at 4 to 6 years of age was also evaluated. Seroprotective antibody levels against diphtheria (> or = 0.01 IU/ml), tetanus (> or = 0.10 IU/ml), and polioviruses (> or = 8 1/dil) were maintained 4-6 years after primary-vaccination and first booster by > or = 92.7% of children, and anti-pertussis antibodies > or = 5 EU/ml were observed in the majority of children. The second booster with DTaP-IPV elicited a strong response for all antigens. GMT or GMC ratios for all antigens at the pre- and post-booster samples were from 4.7 to 52.5. Primary vaccination at 2, 4, 6 and a booster at 18-19 months of age with the DTaP-IPV//PRP-T vaccine induced satisfactory antibody persistence at 4-6 years of age. A second booster with DTaP-IPV induced a strong immune response and was well tolerated.

Antibody persistence after primary and booster doses of a pentavalent vaccine against diphtheria, tetanus, acellular pertussis, inactivated poliovirus, haemophilus influenzae type B vaccine among Thai children at 18-19 months of age.

The World Health Organization recommends a booster dose of a pertussis-containing vaccine for children aged 1-6 years, preferably during the second year of life. This study assessed the immunogenicity and safety of a pentavalent combination vaccine containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, and conjugated-Hib polysaccharide antigens, [(DTaP-IPV//PRP-T (Pentaxim)], as a booster at 18-19 months of age. Participants had received primary doses of the same vaccine at 2, 4 and 6 months of age. Antibody concentrations were measured immediately before and one month after the booster dose. Adverse events were evaluated from parental reports. Geometric mean concentrations (GMCs) or titers (GMTs) decreased from post-primary to pre-booster vaccination; however, at least 94.4% of children had protective levels of anti-tetanus (> or = 0.01 IU/ml), antipoliovirus (> or = 81/dil) and anti-PRP (Hib, > or = 0.15 microg/ml) antibodies prior to the booster. Anti-diphtheria antibody titers > or = 0.01 IU/ml were also observed in the majority of children pre-booster. One month after the booster, seroprotection rates were 99.4% for PRP (> or = 1.0 microg/ml), 95.0% for diphtheria (> or = 0.10 IU/ml) and 100% for tetanus (> or = 0.1 IU/ml) and poliovirus types 1, 2, 3 (> or = 81/dil). At least 93.1% of subjects had 4 fold post-booster increases in anti-pertussis antibody titers. GMCs increased from 14.0 to 307.3 EU/ml and from 13.9 to 271.9 EU/ml for anti-PT and anti-FHA, respectively. Anti-PRP GMC increased from 1.2 to 62.2 microg/ml. The booster was well tolerated. A booster dose during the second year of life was safe and induced a strong immune response, indicative of long-term protection.

Public Health Value of a Hypothetical Pneumococcal Conjugate Vaccine (PCV) Introduction: A Case Study.

Background: Understanding the public health value of a vaccine at an early stage of development helps in valuing and prioritizing the investment needed. Here we present the potential cost-effectiveness of an upcoming 12 valent pneumococcal conjugate vaccine (PCV 12) in the case study country, Thailand. Methods: The cost-effectiveness analysis included a hypothetical scenario of three doses (2 + 1 regimen) PCV12 introduction in the national immunization program of Thailand compared to no PCV, PCV10, and PCV13 among <6 months old from a societal perspective with a lifetime horizon and one-year cycle length. Data from Thailand, as well as assumptions supported by the literature, were used in the analysis. The price of PCV12 was assumed similar to that of PCV10 or PCV13 for GAVI's eligible countries based on inputs from stakeholder meeting. A one-way sensitivity analysis was conducted using 0.5−1.5 times the base price of PCV12. Results were presented in incremental cost-effectiveness ratio (ICER) in terms of monetary value per quality-adjusted life-year (QALY) gained. Results: Vaccination with PCV12 among a hypothetical cohort of 100,000 Thai children is expected to avert a total of 5358 cases which includes 5 pneumococcal meningitis, 43 pneumococcal bacteremia, 5144 all-cause pneumonia, and 166 all-cause acute otitis media compared to no vaccination. The national PCV12 vaccination program is a cost-saving strategy compared to the other three strategies. The one-way sensitivity analysis showed PCV12 is a cost-saving strategy when 1.5 times the base price of PCV12 was assumed. Conclusions: Within the limitations of hypothetical assumptions and price points incorporated, the study indicates the potential public health value of PCV12 in Thailand.

Immunogenicity and Reactogenicity of mRNA BNT162b2 COVID-19 Vaccine among Thai Adolescents with Chronic Diseases.

Adolescents with underlying diseases are at risk of severe COVID-19. The immune response of BNT162b2 may be poor among immunocompromised adolescents. We aim to describe immunogenicity of mRNA BNT162b2 among adolescents who are immunocompromised or have chronic diseases. We recruited adolescents 12-18 years of age; group A impaired-immunity (post-transplantation, cancer, on immunosuppressive drugs) and group B chronic diseases. A two-dose regimen of BNT162b2 was given. Immunogenicity was determined by surrogate virus neutralization test (sVNT) and IgG against receptor-binding domain (RBD). From August to October 2021, 312 adolescents, with a median age (IQR) of 15 years (13.7-16.5), were enrolled (group A 100, group B 212). The geometric means (GMs) of sVNT (% inhibition) against Delta strain and anti-RBD IgG (BAU/mL) after the 2nd dose among group A were: post-transplantation recipients 52.9 (95% CI 37.7-74.2) and 233.6 (95% CI 79-690.6); adolescents with cancer 62.3 (95% CI 29.2-133.1) and 214.9(95% CI 34.2-1348.6); and adolescents with other immunosuppressive conditions 66.7 (95% CI 52.4-84.8) and 849.8 (95% CI 393.4-1835.8). In group B were: adolescents living with HIV 98 (95% CI 97.3-98.8) and 3240.3 (95% CI 2699-3890.2), and adolescents with other chronic disease 98.6 (95% CI 98.3-98.9) and 3818.5 (95% CI 3490.4-4177.4). At day 90, immunity declined; among impaired-immunity participants were 43.9 (95% CI 30.8-62.4) and 178.7 (95% CI 91.2-350.1) and adolescents with chronic diseases were 90.6 (95% CI 88.4-92.8) and 1037.1 (95% CI 933.3-1152.5). In conclusion, adolescents with impaired immunity had a poor response to 2-doses of BNT162b2, additional dose should be considered. Adolescents with chronic diseases had excellent response but immunity waned after 3 m, booster dose may be required.

Invasive meningococcal disease in Malaysia, Philippines, Thailand, and Vietnam: An Asia-Pacific expert group perspective on current epidemiology and vaccination policies.

Invasive meningococcal disease (IMD) imposes a significant burden on the global community due to its high case fatality rate (4-20%) and the risk of long-term sequelae for one in five survivors. An expert group meeting was held to discuss the epidemiology of IMD and immunization policies in Malaysia, Philippines, Thailand, and Vietnam. Most of these countries do not include meningococcal immunization in their routine vaccination programs, except for high-risk groups such as immunocompromised people and pilgrims. It is difficult to estimate the epidemiology of IMD in the highly diverse Asia-Pacific region, but available evidence indicate serogroup B is increasingly dominant. Disease surveillance systems differ by country. IMD is not a notifiable disease in some of them. Without an adequate surveillance system in the region, the risk and the burden of IMD might well be underestimated. With the availability of new combined meningococcal vaccines and the World Health Organization roadmap to defeat bacterial meningitis by 2030, a better understanding of the epidemiology of IMD in the Asia-Pacific region is needed.

Prevalence and correlates of GB virus C infection in HIV-infected and HIV-uninfected pregnant women in Bangkok, Thailand.

GB virus C (GBV-C) is an apathogenic virus that has been shown to inhibit HIV replication. This study examined the prevalence and correlates of GBV-C infection and clearance in three cohorts of pregnant women in Thailand. The study population consisted of 1,719 (1,387 HIV-infected and 332 HIV-uninfected) women from three Bangkok perinatal HIV transmission studies. Stored blood was tested for GBV-C RNA, GBV-C antibody, and if RNA-positive, genotype. Risk factors associated with the prevalence of GBV-C infection (defined as presence of GBV-C RNA and/or antibody) and viral clearance (defined as presence of GBV-C antibody in the absence of RNA) among women with GBV-C infection were examined using multiple logistic regression. The prevalence of GBV-C infection was 33% among HIV-infected women and 15% among HIV-uninfected women. GBV-C infection was independently associated (AOR, 95% CI) with an increasing number of lifetime sexual partners (referent-1 partner, 2 partners [1.60, 1.22-2.08], 3-10 partners [1.92, 1.39-2.67], >10 partners [2.19, 1.33-3.62]); injection drug use (5.50, 2.12-14.2); and HIV infection (3.79, 2.58-5.59). Clearance of GBV-C RNA among women with evidence of GBV-C infection was independently associated with increasing age in years (referent <20, 20-29 [2.01, 1.06-3.79] and ≥30 [3.18, 1.53-6.60]), more than 10 lifetime sexual partners (3.05, 1.38-6.75), and HIV infection (0.29, 0.14-0.59). This study found that GBV-C infection is a common infection among Thai women and is associated with HIV infection and both sexual and parenteral risk behaviors.

Immunizing children aged 9 to 15 months with live attenuated SA14-14-2 Japanese encephalitis vaccine in Thailand.

The authors aimed to evaluate the safety and immunogenicity of a live attenuated SA14-14-2 Japanese Encephalitis (JE) vaccine in healthy Thai infants. One hundred and fifty subjects aged 9-15 months were vaccinated with one dose of this vaccine. Regarding the vaccine safety, during the 28-day post-vaccination follow-up, no vaccine-related serious adverse events were reported. In terms of immunogenicity, the sero-conversion rate of a single dose vaccination was 95% (95% CI, 90.0-97.6%) within 90 days after vaccination and the geometric mean titer (GMT) was 66.1. Eight subjects with JE seronegative on days 28-35 post-vaccination became sero-positive on day 90. Seven subjects who remained sero-negative during days 28-35 and day 90 post-vaccination were successfully sero-converted after receiving a second dose 3 months later. Thus, two doses of this JE vaccine resulted in a 100% (95% CI, 97.3-100%) sero-conversion rate with the GMT of 260.8. Eight children with GMTs lower than protective level after a single vaccination demonstrated a booster response with GMT of 1237 after the second dose of JE vaccination. In conclusion, the live attenuated SA14-14-2 vaccine was safe, well tolerated and highly immunogenic with 95% and 100% sero-conversion rate after one and two doses, respectively. Nevertheless, its long-term immune response and possible influences from natural dengue infection requires further evaluation.