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. © 2024 The Author(s)

BACKGROUND: Domestic influenza vaccine production facilitates a sustainable supply for mitigating seasonal influenza and improves national health security by providing infrastructure and experience for pandemic vaccine production, if needed. METHODS: A Phase III, double blind, randomized controlled trial was conducted from Sep 2019-Oct 2020 in healthy adults 18-64 years in Nakhon Phanom, Thailand. Randomization (3:3:1) compared study vaccine (Tri Fluvac), saline placebo, and an active comparator (licensed vaccine). Primary outcomes were superior efficacy compared to placebo based on RT-PCR-confirmed influenza virus infection within 12 months and non-inferiority compared to active comparator based on immunogenicity (HAI assay) at 28 days. Safety was also assessed. RESULTS: The trial enrolled 4,284 participants (Tri Fluvac = 1,836; placebo = 1,836; active comparator = 612). There were 29 RT-PCR positive influenza infections (10 Tri Fluvac, 5.5/1,000 PY; 19 placebo, 10.4/1,000PY; 0 comparator) for an absolute protective efficacy of 46.4 (95 % CI = -22.0-76.5) compared with placebo, but the power was 43.7 %. Seroconversion difference rates between Tri Fluvac and comparator at Day 28 were 1.74 (95 % CI: -2.77, 6.25), 2.22 (-2.40, 6.84), and -0.57 (-5.41, 4.27) for A(H1N1), A(H3N2), and B strains, respectively. Adverse and severe adverse events occurred in 175 (9.5 %) Tri Fluvac, 177 (10.8 %) placebo, and 66 (10.8 %) comparator arms (p-value = 0.437, Tri Fluvac vs. comparator) CONCLUSIONS: Tri Fluvac was well tolerated, and immunogenicity was non-inferior to the active comparator, meeting U.S. Food and Drug Administration (FDA) criteria for adult vaccine licensure. Few acute respiratory infections were reported during intense COVID-19 pandemic restrictions, resulting in insufficient power to evaluate clinical efficacy.

Background We compared influenza antibody titers among vaccinated and unvaccinated pregnant and non-pregnant women.Methods During 1st June – 30th September 2018, four groups of cohort participants - vaccinated pregnant, unvaccinated pregnant, vaccinated non-pregnant, and unvaccinated non-pregnant women were selected by matching age, gestational age, and the week of vaccination. Serum antibody titers against each strain of 2018 Southern Hemisphere inactivated trivalent influenza vaccine (IIV3) were assessed by hemagglutination inhibition (HI) assay on Day 0 (pre-vaccination) and Day 28 (one month post-vaccination) serum samples. Geometric mean titer (GMT), GMT ratio (GMR), seroconversion (defined as ≥4 fold increase in HI titer), and seroprotection (i.e. HI titer ≥1:40) were compared across the study groups using multilevel regression analyses, controlling for previous year vaccination from medical records and baseline antibody levels.Results A total of 132 participants were enrolled in the study (33 in each of the four study groups). The baseline GMTs were similar for influenza A(H1N1), A(H3N2), and B vaccine strains among all four groups (all p-values >0.05). After one month, both vaccinated groups had significantly higher GMT, GMR, seroconversion, and seroprotection than their unvaccinated controls (all p-values <0.05). The seroconversion rate was over 60% for any strain among the vaccinated groups, with the highest (88.8%) observed against A(H1N1) in the vaccinated pregnant group. Similarly, at least 75% of the vaccinated participants developed seroprotective antibody levels against all three strains; the highest seroprotection was found against A(H3N2) at 92.6% among vaccinated non-pregnant participants. Pregnant women had similar antibody responses (post-vaccination GMT, GMR, seroconversion, and seroprotection) to non-pregnant women for all three strains of IIV3 (all p>0.05).Conclusions The 2018 seasonal IIV3 was immunogenic against all three vaccine strains and pregnancy did not seem to alter the immune response to IIV3. These findings support the current influenza vaccination recommendations for pregnant women.Competing Interest StatementThe authors have declared no competing interest.Clinical TrialThai Clinical Trials Registry ID: TCTR20201014004Funding StatementThis study was partially supported by the Nakhon Phanom Provincial Hospital Foundation (ref no. NP 0032.202.3/7) secured by KP and SN. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The study protocol was reviewed and approved by the Ethical Review Committee of Thammasat University (Ref no. MTU-EC-ES-4-217/60). Approval of local ethics committee of Nakhon Phanom Hospital (No. NP-EC11-No.4/2560) was also received prior to the data collection.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAll relevant data are within the paper and the supporting files.

The emergence of SARS-CoV-2 necessitated the rapid deployment of tests to diagnose COVID-19. To monitor the accuracy of testing across the COVID-19 laboratory network in Thailand, the Department of Medical Sciences under the Ministry of Public Health launched a national external quality assessment (EQA) scheme using samples containing inactivated SARS-CoV-2 culture supernatant from a predominant strain in the early phase of the Thailand outbreak. All 197 laboratories in the network participated; 93% (n=183) of which reported correct results for all 6 EQA samples. Ten laboratories reported false-negative results, mostly for samples with low viral concentrations, and 5 laboratories reported false-positive results (1 laboratory reported false positives and false negatives). An intralaboratory investigation of 14 laboratories reporting incorrect results revealed 2 main causes of error: (1) RNA contamination of the rRT-PCR reaction and (2) poor-quality RNA extraction. Specific reagent combinations were significantly associated with false-negative reports. Thailand's approach to national EQA for SARS-CoV-2 can serve as a roadmap for other countries interested in implementing a national EQA program to ensure laboratories provide accurate testing results, which is crucial in diagnosis, prevention, and control strategies. A national EQA program can be less costly and thus more sustainable than commercial EQA programs. National EQA is recommended to detect and correct testing errors and provide postmarket surveillance for diagnostic test performance.

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.

BACKGROUND: We compared influenza antibody titers among vaccinated and unvaccinated pregnant and non-pregnant women. METHODS: During 1st June- 30th September 2018, four groups of cohort participants-vaccinated pregnant, unvaccinated pregnant, vaccinated non-pregnant, and unvaccinated non-pregnant women were selected by matching age, gestational age, and the week of vaccination. Serum antibody titers against each strain of 2018 Southern Hemisphere inactivated trivalent influenza vaccine (IIV3) were assessed by hemagglutination inhibition (HI) assay on Day 0 (pre-vaccination) and Day 28 (one month post-vaccination) serum samples. Geometric mean titer (GMT), GMT ratio (GMR), seroconversion (defined as ≥4 fold increase in HI titer), and seroprotection (i.e. HI titer ≥1:40) were compared across the study groups using multilevel regression analyses, controlling for previous year vaccination from medical records and baseline antibody levels. RESULTS: A total of 132 participants were enrolled in the study (33 in each of the four study groups). The baseline GMTs for influenza A(H1N1), A(H3N2), and B vaccine strains were not significantly different among all four groups (all p-values >0.05). After one month, both vaccinated groups had significantly higher GMT, GMR, seroconversion, and seroprotection than their unvaccinated controls (all p-values <0.05). The seroconversion rate was over 60% for any strain among the vaccinated groups, with the highest (88.8%) observed against A(H1N1) in the vaccinated pregnant group. Similarly, at least 75% of the vaccinated participants developed seroprotective antibody levels against all three strains; the highest seroprotection was found against A(H3N2) at 92.6% among vaccinated non-pregnant participants. Antibody responses (post-vaccination GMT, GMR, seroconversion, and seroprotection) were not significantly different between pregnant and non-pregnant women for all three strains of IIV3 (all p>0.05). CONCLUSIONS: The 2018 seasonal IIV3 was immunogenic against all three vaccine strains and pregnancy did not seem to alter the immune response to IIV3. These findings support the current influenza vaccination recommendations for pregnant women.

BACKGROUND: Adults with cardiopulmonary conditions may be at increased risk of influenza and respiratory syncytial virus (RSV) infection, but it is not well-established and few data are available from middle-income countries. METHODS: Using data from a prospective cohort study of influenza vaccine effectiveness, we estimated and compared the incidences of influenza and RSV between community-dwelling Thai adults aged ≥ 65 years with and without cardiopulmonary conditions. During May 2015-May 2017, older adults in a rural province in Thailand were followed-up with weekly surveillance for acute respiratory illness (ARI), defined broadly as new onset or worsening of cough with or without fever, and hospitalized ARI. When ill, nasal self-swabs and/or nasopharyngeal swabs were collected for reverse-transcription polymerase chain reaction testing. We used Poisson regression to calculate incidence rate ratios (IRR), adjusting for age, sex, current smoking, number of hospital visits, weekly influenza activity, and influenza vaccination. RESULTS: Overall, 3220 adults with a median age of 71 years (IQR 68-76) were enrolled; 1324 (41.1%) were male; and 313 (9.7%) had ≥1 underlying cardiopulmonary condition, most commonly chronic obstructive pulmonary disease (131; 41.2%) or asthma (73; 23.3%). Participants with cardiopulmonary conditions had higher incidences of ARI, influenza, and RSV than those without (Adjusted IRR: 1.84, 95% CI 1.64-2.07; 1.86, 95% CI 1.07-3.26; 2.04, 95% CI 1.11-3.76, respectively). CONCLUSION: Older adults in rural Thailand with cardiopulmonary conditions have increased rates of ARI, influenza, and RSV infections. Our findings support efforts to ensure this population has access to influenza vaccines and other respiratory illness prevention measures.

BACKGROUND: Human immunodeficiency virus (HIV)-infected persons are at a higher risk of severe influenza. Although we have shown that a standard-dose intradermal influenza vaccine versus a standard-dose intramuscular influenza vaccine does not result in differences in hemagglutination-inhibition titers in this population, a comprehensive examination of cell-mediated immune responses remains lacking. METHODS: Serological, antigen-specific B-cell, and interleukin 2-, interferon gamma-, and tumor necrosis factor alpha-secreting T-cell responses were assessed in 79 HIV-infected men and 79 HIV-uninfected men. RESULTS: The route of vaccination did not affect the immunoglobulin A and immunoglobulin G (IgG) plasmablast or memory B-cell response, although these were severely impaired in the group with a CD4+ T-cell count of <200 cells/muL. The frequencies of IgG memory B cells measured on day 28 after vaccination were highest in the HIV-uninfected group, followed by the group with a CD4+ T-cell count of >/=200 cells/muL and the group with a CD4+ T-cell count of <200 cells/muL. The route of vaccination did not affect the CD4+ or CD8+ T-cell responses measured at various times after vaccination. CONCLUSIONS: The route of vaccination had no effect on antibody responses, antibody avidity, T-cell responses, or B-cell responses in HIV-infected or HIV-uninfected subjects. With the serological and cellular immune responses to influenza vaccination being impaired in HIV-infected individuals with a CD4+ T-cell count of <200 cells/muL, passive immunization strategies need to be explored to protect this population. CLINICAL TRIALS REGISTRATION: NCT01538940.

Seasonal trivalent influenza vaccines (TIV) have been recommended since 2008 for people >/=65 years of age in Thailand. While two distinct antigenic lineages of influenza B virus, namely, B/Yamagata and B/Victoria, often co-circulate in Thailand, TIV contains only one influenza B lineage. Little is known regarding cross-protection among older Thai persons offered by current TIV against heterologous influenza B lineage. Kinetics, longevity and cross-antibody response to both influenza B lineages were measured in 85 healthy Thai persons >/=65 years of age vaccinated with TIV containing B Phuket/3073/2013 (Yamagata lineage) in 2015-2016 season and then with TIV containing B/Brisbane/60/2008 (Victoria lineage) in 2016-2017 season. Hemagglutination-inhibition assays were performed on blood specimens collected at five time intervals during the study period. Seroconversion rate, seroprotection rate, geometric mean titer (GMT), and GMT ratio peaked at one month after the first vaccination and declined over time. At one-month post second vaccination, antibody response was shown not only for homologous B/Brisbane virus but also for heterologous B/Phuket virus. The study suggests the elderly could develop antibody response to both influenza B lineages when primed with TIV containing one B lineage and boosted with a TIV vaccination containing the other B lineage. Although more research is needed, in resource-limited countries where quadrivalent influenza vaccines are not avail-able, repeated TIV vaccination may be beneficial in developing immunological protection against influenza B in people >/= 65 years of age.

BACKGROUND: Frailty is associated with increased risk of mortality and decline in functional status among older adults. Older adults are at increased risk of severe disease from acute respiratory illness (ARIs), but ARI effects on frailty status among older adults are not well understood. We evaluated how ARIs affect short-term frailty status among community-dwelling adults aged >/=65 years in Nakhon Phanom, Thailand. METHODS: During May 2015 to May 2017, older adults were contacted weekly to identify ARIs as part of a community-based longitudinal cohort study. Each participant's frailty status was assessed at baseline and every 6 months using the Vulnerable Elders Survey-13 (VES-13). We selected cohort participants with an ARI and compared them with a sample of participants without an ARI matched on age, sex, influenza vaccination status, and most recent VES-13 score. For these matched cohort members, an additional VES-13 was recorded at 3-4 weeks after the ARI episode date. RESULTS: Of 3220 cohort study participants, 114 participants with an ARI and 111 comparison participants without an ARI were selected for the matched cohort; three comparison participants were matched to two ARI cases. We found no statistically significant difference between ARI and non-ARI participants in modified VES-13 score 3-4 weeks post-episode (cases = 0.90, controls = 0.63, P = 0.07). Only two ARI episodes required hospitalization. CONCLUSIONS: Primarily mild ARIs did not affect short-term frailty status among community-dwelling older adults in Thailand. As few cases of severe ARI were detected, the contribution of severe ARI to changes in frailty requires further investigation.

BACKGROUND: We conducted a two-year prospective cohort study to measure the effectiveness of trivalent inactivated influenza vaccine (IIV3) to prevent laboratory-confirmed influenza among community-dwelling Thai adults aged >/=65years during 2015-16 and 2016-17 influenza seasons. METHODS: In 2015, we enrolled a cohort of 3220 participants. Trained health volunteers collected baseline data and followed participants for two years with weekly surveillance for new or worsened cough with self-collection of nasal swabs. Vaccine effectiveness (VE) was estimated as 100%x(1- rate ratio of rRT-PCR -confirmed influenza) among vaccinated versus unvaccinated participants. Propensity score stratification was used to reduce differences between vaccinated and unvaccinated participants associated with access to and receipt of IIV3. FINDINGS: During 2015-16 and 2016-17, 1666 (52%) and 1498 (48%) participants received IIV3, respectively. The overall incidence of influenza during the two seasons was 14.3/1000 person-years among vaccinated participants and 20.2/1000 person-years among unvaccinated participants. VE was -4% (95% confidence interval [CI], -83%-40%) during 2015-16 when there was poor antigenic match between the dominant circulating A/H3N2 viruses and the vaccine strain, and 50% (95% CI, 12-71%) during 2016-17 when circulating and vaccine strains were well-matched. Of all three influenza subtypes in both years, significant protection was observed only against Influenza A/H3N2 during 2016-17 (VE, 49%; 95% CI, 3-73%). INTERPRETATION: During a season with well-matched circulating and vaccine strains, IIV3 was moderately effective against laboratory-confirmed influenza among older adults in Thailand.

BACKGROUND: Information on the burden, characteristics and seasonality of non-influenza respiratory viruses is limited in tropical countries. OBJECTIVES: Describe the epidemiology of selected non-influenza respiratory viruses in Thailand between June 2010 and May 2014 using a sentinel surveillance platform established for influenza. METHODS: Patients with influenza-like illness (ILI; history of fever or documented temperature >38 degrees C, cough, not requiring hospitalization) or severe acute respiratory infection (SARI; history of fever or documented temperature >38 degrees C, cough, onset <10 days, requiring hospitalization) were enrolled from 10 sites. Throat swabs were tested for influenza viruses, respiratory syncytial virus (RSV), metapneumovirus (MPV), parainfluenza viruses (PIV) 1-3, and adenoviruses by polymerase chain reaction (PCR) or real-time reverse transcriptase PCR RESULTS: We screened 15,369 persons with acute respiratory infections and enrolled 8106 cases of ILI (5069 cases <15 years old) and 1754 cases of SARI (1404 cases <15 years old). Among ILI cases <15 years old, influenza viruses (1173, 23%), RSV (447, 9%) and adenoviruses (430, 8%) were the most frequently identified respiratory viruses tested, while for SARI cases <15 years old, RSV (196, 14%) influenza (157, 11%) and adenoviruses (90, 6%) were the most common.. The RSV season significantly overlapped the larger influenza season from July-November in Thailand. CONCLUSIONS: The global expansion of influenza sentinel surveillance provides an opportunity to gather information on the characteristics of cases positive for non-influenza respiratory viruses, particularly seasonality, although adjustments to case definitions may be required. This article is protected by copyright. All rights reserved.

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.

BACKGROUND: Self-collection of nasal swabs could improve the timeliness of influenza virus detection in older adults. OBJECTIVES: Measure the acceptability, adequacy, timeliness and validity of self-collected nasal swabs among adults ≥65 years in Thailand. METHODS: Our evaluation consisted of two parts: a one-month study among randomly-selected, community-dwelling older adults to simulate community-based surveillance for acute respiratory infections (ARI); and a clinic study of older adults with ARI to evaluate the sensitivity and specificity of self-collected nasal swabs for influenza virus infection compared with healthcare worker (HCW)-collected nasal and nasopharyngeal swabs. RESULTS: In the community study, 24% of participants experienced an ARI during the observation period. All (100%) participants with an ARI self-collected nasal swabs within 72 hours of symptom onset of which 92% were considered adequate samples. In the clinic study, 45% of patients with ARI presented within 72 hours of symptom onset. The sensitivity of self-collected nasal swabs for detection of influenza virus infection was 78% (95% CI 40-97) compared to nasopharyngeal and 88% (95% CI 47-100) compared to nasal swabs collected by HCW. Specificity was 100% (95% CI 97-100) compared to both methods. Self-collection of nasal swabs was found acceptable by 99% of participants in both studies. CONCLUSIONS: Self-collection of nasal swabs was acceptable to older adults in Thailand who were able to take adequate samples. Self-collection of nasal swabs may improve the timeliness of sample collection but lower sensitivity will need to be considered. This article is protected by copyright. All rights reserved.

At 0033 h on Sept 9, 2015, a 17-year-old Thai woman, 33 weeks and 4 days into her first pregnancy and no medical history of note, presented to the emergency room of Phon Thong district hospital with a 1 day history of fever, cough, and sore throat. On presentation she was febrile (temperature 39·2°C) and tachycardic (pulse 129 beats per min) with a respiratory rate of 22 breaths per min and blood pressure 130/81 mm Hg. She was diagnosed with bronchitis, prescribed amoxicillin, paracetamol, and bromhexine, and discharged home. | She attended a scheduled antenatal care clinic appointment the next morning at 0800 h and was afebrile (temperature 37·1°C). Ultrasonography showed twin infants with estimated bodyweights of 1900 g and 2000 g and on stress test fetal heart beats were normal. She returned to hospital for a third time at 2030 h after experiencing contractions. On examination, her cervix was found to be dilated to 3 cm. She was febrile (39·0°C) and tachycardic (pulse 136 beats per min), with a respiratory rate of 20 breaths per min and blood pressure 144/81 mm Hg. At 2045 h, her blood pressure rose to 150/100 mm Hg and she reported mild dyspnoea. Fetal heart monitoring showed fetal tachycardia. At 2100 h, her respiratory rate increased to 28 breaths per min with oxygen saturation (SpO2) 86% on room air and 96% on 10 L oxygen. Fine crepitations were noted on lung examination, and she was started on ceftriaxone. At 2130 h, before being transferred to the provincial hospital, she developed tachycardia (pulse 140 beats per min), tachypnoea (respiratory rate 30 breaths per min), hypertension (blood pressure 200/120 mm Hg), and hypoxia (SpO2 70% on room air). She was intubated (400 mL of pink frothy sputum was noted on endotracheal aspiration) and given 4 g of intravenous MgSO4 to prevent seizures. During transfer she was started on external positive end expiratory pressure ventilation, and SpO2 improved to 88–90%. Fetal heart sounds decreased to 80–90 beats per min.

BACKGROUND: Physicians play a major role in influencing acceptance and uptake of vaccines. However, little is known about physicians' perspectives on influenza vaccination of pregnant women in Thailand, for whom vaccine coverage is estimated at <1%. METHOD: In 2013, a self-administered questionnaire on physicians' perceptions, attitudes and practices related to influenza vaccination for pregnant women was distributed to 1,134 hospitals with an antenatal care clinic (ANC) in Thailand. At each hospital, one physician working at the ANC completed the survey. Predictors of routine recommendation of influenza vaccine were analyzed utilizing log-binomial regression. RESULTS: A total of 580 (51%) complete responses were received from physicians practicing at ANCs. A favorable attitude towards vaccination was expressed by 436 (75%) physicians, however only 142 (25%) reported routinely recommending influenza vaccine to pregnant women in their current practice. Physicians were more likely to recommend influenza vaccine routinely when they had more than three years of practice (prevalence ratio [PR] 1.9, 95% CI 1.2-2.3), had treated pregnant women for influenza (PR 1.8, 95% CI 1.3-2.7), perceived the influenza vaccine to be effective (moderate level: PR 1.6, 95% CI 1.1-2.4; high level: PR 1.9, 95% CI 1.3-2.9) and were aware of the Ministry of Public Health's (MOPH) recommendation of influenza vaccination in pregnancy (PR 1.3, 95% CI 1.1-1.7). Vaccine not being available, perception that policy was ambiguous and lack of awareness of MOPH recommendations were the most commonly cited barriers to routine recommendation of influenza vaccine. CONCLUSION: Despite a national policy to vaccinate pregnant women for influenza, only 25% of Thai physicians working in ANCs routinely recommend vaccination. Strategies are needed to increase vaccine availability and free vaccine services, address clinician concerns over vaccine effectiveness and expand healthcare provider awareness of MOPH recommendations.

The incidence of pneumococcal pneumonia among adults is a key driver for the cost-effectiveness of pneumococcal conjugate vaccine used among children. We sought to obtain more accurate incidence estimates among adults by including results of pneumococcal urine antigen testing (UAT) from population-based pneumonia surveillance in two Thai provinces. Active surveillance from 2006 to 2011 identified acute lower respiratory infection (ALRI)-related hospital admissions. Adult cases of pneumococcal pneumonia were defined as hospitalized ALRI patients aged ≥ 18 years with isolation of Streptococcus pneumoniae from blood or with positive UAT. Among 39,525 adult ALRI patients, we identified 481 pneumococcal pneumonia cases (105 by blood culture, 376 by UAT only). Estimated incidence of pneumococcal pneumonia hospitalizations was 30.5 cases per 100,000 person-years (2.2 and 28.3 cases per 100,000 person-years by blood culture and UAT, respectively). Incidence varied between 22.7 in 2007 and 43.5 in 2010, and increased with age to over 150 per 100,000 person-years among persons aged ≥ 70 years. Viral coinfections including influenza A/B, respiratory syncytial virus (RSV), and adenovirus occurred in 11% (44/405) of pneumococcal pneumonia cases tested. Use of UAT to identify cases of pneumococcal pneumonia among adults in rural Thailand substantially increases estimates of pneumococcal pneumonia burden, thereby informing cost-effectiveness analyses and vaccine policy decisions.

In Nakhon Phanom, Thailand, we identified 38 hospitalized patients with Streptococcus suis infection during 2006-2012. Deafness developed in 12 patients; none died. Thirty-five reported recent exposure to pigs/pork. Annual incidence was 0.1-2.2 cases/100,000 population (0.2-3.2 in persons >20 years of age). Clinicians should consider S. suis infection in areas where pig exposure is common.