Vaccine acceptance in the general public is essential in controlling the coronavirus disease 2019 (COVID-19) pandemic. The study aimed to assess the COVID-19 vaccine hesitancy in the adult population of Mongolia, and determine the associated factors. A total of 2875 individuals from urban and rural areas were recruited, and completed an online survey. Older age, urban residence, previous vaccination, high education, good knowledge of side effects, and a personal view of the importance of vaccines were associated with vaccine acceptability, whereas gender and religion were not. Receiving COVID-19 vaccine information from official government pages was related to a higher acceptance rate. Reliance on social media as a source of COVID-19 vaccine information was associated with high level of vaccine hesitancy. The side effects and the type of the COVID-19 vaccine were a major reason for hesitation. Countering false information regarding COVID-19 vaccines on social media, and promoting vaccine importance on general news websites is necessary. Moreover, providing clear and direct educational materials through official communication channels on the safety and efficacy of COVID-19 vaccines alongside information on COVID-19 symptoms, vaccine side effects, and location of vaccine administration centers among the younger populations, rural residents, and those with lower education is needed.

Hepatitis B, C, and D virus infections are a major public health problem, and Mongolia has one of the highest prevalences of dual and triple infections in the world. We aimed to determine the seroprevalence of hepatitis infection and dual or triple hepatitis infections among 10–64-year-olds. A questionnaire was used to identify risk factors for hepatitis infection, and seromarkers were measured by the fully automated immunologic analyzer HISCL-5000. Among a total of 10,040 participants, 8.1% of the population aged 10–64 was infected with HBV, 9.4% with HCV, and 0.4% with HBV and HCV, and the prevalence of the disease varied by age, sex, and the area of residence. Young people were particularly unaware of their hepatitis infection status. A small proportion of children aged 10 to 19 years and the majority of adults younger than 30 years were unaware of their HBV and HCV infection. Men were also more likely to be unaware of their HBV and HCV infection status than women. The results suggested that the prevalence of infection in the general population is high and that most people are unaware that they are infected or have become chronic carriers. Identifying mono-, co-, or triple-infection status is critical to prevent the rapid progression of liver disease among the Mongolian population.

Objectives: Infections with hepatitis B, C, and D virus (HBV, HCV, and HDV) are a major public health problem and lead to serious complications such as cirrhosis and hepatocellular carcinoma. We aimed to determine the seroprevalence of hepatitis B surface antigen (HBsAg), anti-HCV, anti-HDV immunoglobulin G, alpha-fetoprotein (AFP), and dual and triple hepatitis virus infections in Mongolia.Methods: A total of 2313 participants from urban and rural regions were randomly recruited for this cross-sectional study. A questionnaire was used to identify the risk factors for hepatitis virus infections, and the seromarkers were measured using immunoassay kits.Results: Among all participants, the prevalence of HBV, HCV, and HDV was 15.6%, 36.6%, and 14.3%, respectively. The infection rates were significantly higher in females and participants with a lower education level, rural residence, older age, and a history of blood transfusion. HBV and HCV co-infection was found in 120 (5.2%) participants and HBV, HCV, and HDV triple infection was detected in 67 (2.9%) participants. The prevalence of elevated AFP was 2.7%, 5.5%, and 2.6% higher in participants who were seropositive for HBsAg (p=0.01), anti-HCV (p<0.001), and anti-HDV (p=0.022), respectively. Elevated AFP was more prevalent in participants co-infected with HBV and HCV (5.8%, p=0.023), HBV and HDV (6.0%, p<0.001), and triple-infected with HBV, HCV, and HDV (7.5%) than in uninfected individuals.Conclusions: Nearly half (49.8%) of the study population aged ≥40 years were infected with HBV, HCV, or HDV, and 22.4% had dual or triple infections.

This study was conducted to compare whether the indoor air pollutants had changed in 2020 compared to 2019 in accordance with the raw coal use ban. A total 295 households and 10 family health centers were recruited from 6 districts of Sukhbaatar, Bayangol, Chingeltei, Songinokhairkhan, Khan-Uul and Bayanzurkh districts of the Ulaanbaatar city. The average 24-hour concentration of fine particles is 102.7 µg/m³ in total households, which is 2.1 times higher than the Mongolian air quality standard. The average concentration of PM2.5 which was measured in 2019, when the raw coal usage was available, is decreased by 40 percent (from 176.1 µg/m3 to 105.7 µg/m3) compared to the year of 2020 when improved fuel usage was introduced. Particulate matter pollution varied significantly by dwelling and heating types. The concentration of indoor PM2.5 was relatively high (128.4-150.2 µg/m³) in gers and houses with traditional stoves, whereas it was low (81.2–86.3 µg/m³) in gers and houses with improved stoves. PM2.5 concentrations varied diurnally in gers, houses and apartments with peak concentrations from 07:00 to 11:00 in the morning (68–96 µg/m³) and from 18:00 to 20:00 in the evening (71-85.5 µg/m³). PM2.5 concentrations varied by district, with relatively low concentrations in Khan-Uul and Sukhbaatar districts (87.9 µg/m³) as compared to households in Songinokhairkhan and Bayanzurkh districts (108.1 µg/m³). The average 24-hour concentration of carbon monoxide was 17.6 ± 9.2 mg/m³ in gers and houses, which is 2.5 times higher than the WHO recommended level with higher concentrations in houses than in gers. Compared to the winter of 2019 (176.1 µg/m³), the mean concentration of PM2.5 was measured as 105.7 µg/m³ (40% lower) in gers/houses who used refined/improved "Good" fuel in Jan-Feb of 2020. Thus, indoor PM2.5 concentration in gers and houses had decreased significantly (p < 0.05) in winter when improved fuels usage was introduced.