Prevalence of HPV infection among Thai schoolgirls in the north-eastern provinces in 2018: implications for HPV immunization policy

OBJECTIVE

The aim of this study was to determine the prevalence of high-risk (HR) and vaccine-type human papillomavirus (HPV) infection among Thai schoolgirls who were not included in the national HPV immunization program.

METHODS

Cross-sectional surveys were conducted among grade 10 (15-16 years old) and grade 12 (17-18 years old) schoolgirls in two provinces of Thailand. Urine samples were collected using the Colli-Pee^Ⓡ device from November 2018 to February 2019. The samples were initially tested using Cobas^Ⓡ 4800. Subsequently, all Cobas-positive samples and 1:1 matched Cobas-negative samples were tested by Anyplex^Ⓡ assay. Prevalences of any HPV, any HR HPV, vaccine-type HPV, and individual HR HPV types were estimated by school grade.

RESULTS

Prevalences of any HPV and any HR HPV were 11.6% and 8.6% for grade 10, and 18.5% and 12.4% for grade 12 schoolgirls, respectively. Prevalences of bivalent vaccine-type HPV infection in grades 10 and 12 were 3.4% and 4.5%, respectively. Prevalences of quadrivalent and nonavalent vaccine-type HPV infections were 4.0%/6.6% and 6.4%/10.4% in grades 10 and 12, respectively. HPV16 was the most common type detected, followed by HPV58, 51, and 52. Circulating HR HPV types were similar between the school grades.

CONCLUSION

A substantial burden of HR HPV infections was found among unvaccinated high school girls in Thailand.

Public health policies and health-care workers' response to the COVID-19 pandemic, Thailand

Since January 2020, the coronavirus disease 2019 (COVID-19) pandemic has had a far-reaching impact on global morbidity and mortality. The effects of varying degrees of implementation of public health and social measures between countries is evident in terms of widely differing disease burdens and levels of disruption to public health systems. Despite Thailand being the first country outside China to report a positive case of COVID-19, the subsequent number of cases and deaths has been much lower than in many other countries. As of 7 January 2021, the number of confirmed COVID-19-positive cases in Thailand was 9636 (138 per million population) and the number of deaths was 67 (1 per million population). We describe the nature of the health workforce and function that facilitated the capacity to respond to this pandemic. We also describe the public health policies (laboratory testing, test-and-trace system and mandatory 14-day quarantine of cases) and social interventions (daily briefings, restriction of mobility and social gatherings, and wearing of face masks) that allowed the virus to be successfully contained. To enhance the capacity of health-care workers to respond to the pandemic, the government (i) mobilized staff to meet the required surge capacity; (ii) developed and implemented policies to protect occupational safety; and (iii) initiated packages to support morale and well-being. The results of the policies that we describe are evident in the data: of the 66 countries with more than 100 COVID-19-positive cases in health-care workers as at 8 May 2020, Thailand ranked 65th.

Case-Control Study of Use of Personal Protective Measures and Risk for SARS-CoV 2 Infection, Thailand

We evaluated effectiveness of personal protective measures against severe acute respiratory disease coronavirus 2 (SARS-CoV-2) infection. Our case-control study included 211 cases of coronavirus disease (COVID-19) and 839 controls in Thailand. Cases were defined as asymptomatic contacts of COVID-19 patients who later tested positive for SARS-CoV-2; controls were asymptomatic contacts who never tested positive. Wearing masks all the time during contact was independently associated with lower risk for SARS-CoV-2 infection compared with not wearing masks; wearing a mask sometimes during contact did not lower infection risk. We found the type of mask worn was not independently associated with infection and that contacts who always wore masks were more likely to practice social distancing. Maintaining >1 m distance from a person with COVID-19, having close contact for <15 minutes, and frequent handwashing were independently associated with lower risk for infection. Our findings support consistent wearing of masks, handwashing, and social distancing to protect against COVID-19.

Extended evaluation of the virologic, immunologic, and clinical course of volunteers who acquired HIV-1 infection in a phase III vaccine trial of ALVAC-HIV and AIDSVAX B/E

BACKGROUND

The Thai Phase III Trial of ALVAC-HIV and AIDSVAX B/E showed an estimated vaccine efficacy (VE) of 31% to prevent acquisition of human immunodeficiency virus (HIV). Here we evaluated the effect of vaccination on disease progression after infection.

METHODS

CD4(+) T-cell counts and HIV viral load (VL) were measured serially. The primary analysis evaluated vaccine efficacy (VEP) as the percent reduction (vaccine vs placebo) in cumulative probability of a primary composite endpoint of clinical and CD4(+) count components at prespecified time points after infection. Secondary analyses of biomarker-based endpoints were assessed using marginal mean and linear mixed models.

RESULTS

There were 61 endpoints in the modified intent-to-treat cohort (mITT; n = 114). There was no evidence for efficacy at 30, 42, 54, and 60 months in the mITT and per protocol (n = 90) cohorts. Estimated VEP (mITT) was15.8% (-21.9, 41.8) at 60 months postinfection. There was weak evidence of lower VL and higher CD4(+) count at 60 and 66 months in the vaccine group. Lower mucosal VL was observed among vaccine recipients, primarily in semen (P = .04).

CONCLUSIONS

Vaccination did not affect the clinical course of HIV disease after infection. A potential vaccine effect on the genital mucosa warrants further study.

Is a HIV vaccine a viable option and at what price? An economic evaluation of adding HIV vaccination into existing prevention programs in Thailand

Background

This study aims to determine the maximum price at which HIV vaccination is cost-effective in the Thai healthcare setting. It also aims to identify the relative importance of vaccine characteristics and risk behavior changes among vaccine recipients to determine how they affect this cost-effectiveness.

Methods

A semi-Markov model was developed to estimate the costs and health outcomes of HIV prevention programs combined with HIV vaccination in comparison to the existing HIV prevention programs without vaccination. The estimation was based on a lifetime horizon period (99 years) and used the government perspective. The analysis focused on both the general population and specific high-risk population groups. The maximum price of cost-effective vaccination was defined by using threshold analysis; one-way and probabilistic sensitivity analyses were performed. The study employed an expected value of perfect information (EVPI) analysis to determine the relative importance of parameters and to prioritize future studies.

Results

The most expensive HIV vaccination which is cost-effective when given to the general population was 12,000 Thai baht (US$1 = 34 Thai baht in 2009). This vaccination came with 70% vaccine efficacy and lifetime protection as long as risk behavior was unchanged post-vaccination. The vaccine would be considered cost-ineffective at any price if it demonstrated low efficacy (30%) and if post-vaccination risk behavior increased by 10% or more, especially among the high-risk population groups. The incremental cost-effectiveness ratios were the most sensitive to change in post-vaccination risk behavior, followed by vaccine efficacy and duration of protection. The EVPI indicated the need to quantify vaccine efficacy, changed post-vaccination risk behavior, and the costs of vaccination programs.

Conclusions

The approach used in this study differentiated it from other economic evaluations and can be applied for the economic evaluation of other health interventions not available in healthcare systems. This study is important not only for researchers conducting future HIV vaccine research but also for policy decision makers who, in the future, will consider vaccine adoption.

Vaccination with ALVAC and AIDSVAX to prevent HIV-1 infection in Thailand

BACKGROUND

The development of a safe and effective vaccine against the human immunodeficiency virus type 1 (HIV-1) is critical to pandemic control.

METHODS

In a community-based, randomized, multicenter, double-blind, placebo-controlled efficacy trial, we evaluated four priming injections of a recombinant canarypox vector vaccine (ALVAC-HIV [vCP1521]) plus two booster injections of a recombinant glycoprotein 120 subunit vaccine (AIDSVAX B/E). The vaccine and placebo injections were administered to 16,402 healthy men and women between the ages of 18 and 30 years in Rayong and Chon Buri provinces in Thailand. The volunteers, primarily at heterosexual risk for HIV infection, were monitored for the coprimary end points: HIV-1 infection and early HIV-1 viremia, at the end of the 6-month vaccination series and every 6 months thereafter for 3 years.

RESULTS

In the intention-to-treat analysis involving 16,402 subjects, there was a trend toward the prevention of HIV-1 infection among the vaccine recipients, with a vaccine efficacy of 26.4% (95% confidence interval [CI], -4.0 to 47.9; P=0.08). In the per-protocol analysis involving 12,542 subjects, the vaccine efficacy was 26.2% (95% CI, -13.3 to 51.9; P=0.16). In the modified intention-to-treat analysis involving 16,395 subjects (with the exclusion of 7 subjects who were found to have had HIV-1 infection at baseline), the vaccine efficacy was 31.2% (95% CI, 1.1 to 52.1; P=0.04). Vaccination did not affect the degree of viremia or the CD4+ T-cell count in subjects in whom HIV-1 infection was subsequently diagnosed.

CONCLUSIONS

This ALVAC-HIV and AIDSVAX B/E vaccine regimen may reduce the risk of HIV infection in a community-based population with largely heterosexual risk. Vaccination did not affect the viral load or CD4+ count in subjects with HIV infection. Although the results show only a modest benefit, they offer insight for future research. (ClinicalTrials.gov number, NCT00223080.)