Assessment of serological responses following vaccination campaigns with type 2 novel oral polio vaccine: a population-based study in Tajikistan in 2021.

BACKGROUND: Novel oral poliovirus vaccine type 2 (nOPV2) was used to control an outbreak of type 2 circulating vaccine derived poliovirus (cVDPV2) in Tajikistan, in 2021. We measured seroconversion and seroprevalence of type 2 polio antibodies in children who were reported to have received two doses of nOPV2 in outbreak response campaigns. METHODS: In this community serosurvey, children born after Jan 1, 2016 were enrolled from seven districts in Tajikistan. Dried blood spot cards were collected before nOPV2 campaigns and after the first and second rounds of the campaigns and were sent to the Centers for Disease Control and Prevention (Atlanta, GA, USA) for microneutralisation assay to determine presence of polio antibodies. The primary endpoint was to assess change in seroprevalence and seroconversion against poliovirus serotype 2 after one and two doses of nOPV2. FINDINGS: 228 (97%) of 236 enrolled children were included in the analysis. The type 2 antibody seroprevalence was 26% (53/204; 95% CI 20 to 33) before nOPV2, 77% (161/210; 70 to 82) after one dose of nOPV2, and 83% (174/209; 77 to 88) after two doses of nOPV2. The increase in seroprevalence was statistically significant between baseline and after one nOPV2 dose (51 percentage points [42 to 59], p<0·0001), but not between the first and second doses (6 percentage points [-2 to 15], p=0·12). Seroconversion from the first nOPV2 dose, 67% (89/132; 59 to 75), was significantly greater than that from the second nOPV2 dose, 44% (20/45; 30 to 60; χ2 p=0·010). Total seroconversion after two nOPV2 doses was 77% (101/132; 68 to 83). INTERPRETATION: Our study demonstrated strong immune responses following nOPV2 outbreak response campaigns in Tajikistan. Our results support previous clinical trial data on the generation of poliovirus type 2 immunity by nOPV2 and provide evidence that nOPV2 can be appropriate for the cVDPV2 outbreak response. The licensure and WHO prequalification of nOPV2 should be accelerated to facilitate wider use of the vaccine. FUNDING: World Health Organization, Centers for Disease Control and Prevention, and Rotary International.

Redressing the epidemics of opioid overdose and HIV among people who inject drugs in Central Asia: the need for a syndemic approach.

BACKGROUND: Accumulating evidence suggests that opioid overdose and HIV infection are burgeoning intertwined epidemics among people who inject drugs (PWID) in Central Asia. To date, however, research on overdose and its associations with HIV risks among PWID in Central Asia remains virtually absent. This paper aims to provide a regional overview of the hidden epidemic of overdose and how it is linked to HIV among PWID in Central Asia, using a syndemic framework that is guided by risk environment research. METHODS: We conducted a comprehensive literature search of peer-reviewed publications and gray literature on opioid overdose and its associations with HIV in five countries of Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) as well as on policies and programs that address these co-occurring epidemics. RESULTS: Regional data indicate high rates of fatal and non-fatal overdose among PWID. Evidence suggests mortality rates from overdose exceed HIV/AIDS as the leading cause of death among PWID. The syndemic framework suggests multiple macro-level and micro-level environmental risk factors that drive the co-occurring epidemics of HIV and overdose. This framework identifies several interacting biological and behavioral risks that result in additive effects for HIV and overdose. CONCLUSION: The high rates of overdose and its associations with HIV underscore the need for a syndemic approach that considers overdose on parity with HIV. Such an approach should focus on the biological, behavioral and structural interactions between these epidemics to reduce social suffering, morbidity and mortality among PWID in Central Asia.

Access to HIV counseling and testing among people who inject drugs in Central Asia: strategies for improving access and linkages to treatment and care.

INTRODUCTION: As a population profoundly affected by the HIV epidemic and in critical need of linkages to HIV treatment and care, PWID in Central Asia remain largely underserved. This paper provides an overview of the current state of HIV testing and counseling in Central Asia for PWID, identifies main barriers leading to gaps in service delivery, and discusses implications for improving strategies that promote HIV testing for PWID. METHODS: We reviewed a number of sources for this paper including unpublished government reports, published papers, and Ministries of Health of Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan country progress reports to the UN General Assembly Special Session on HIV/AIDS (UNGASS) for 2012. RESULTS: Between 29 and 65% of PLWH in some Central Asian countries have been tested for HIV in the last 12 months. The rates have been increasing in the recent years but still are relatively low. Stigma, discrimination, human rights violations, and repressive legislation are barriers to HTC for people who inject drugs (PWID). CONCLUSION: The use of innovative evidence-based HTC models, such as community mobile-vans, self-testing at home, and rapid HIV testing among PWID in Central Asia are discussed and recommendations given regarding amendments in legislation and scaling up of existing community-based pilot projects to support HIV testing among PWID in CA.