Direct Comparison of Antibody Responses to Four SARS-CoV-2 Vaccines in Mongolia

Different vaccines for SARS-CoV-2 are approved in various countries, but few direct comparisons of the antibody responses they stimulate have been reported. We collected plasma specimens in July 2021 from 196 Mongolian participants fully vaccinated with one of four Covid vaccines: Pfizer/BioNTech, AstraZeneca, Sputnik V and Sinopharm. Functional antibody testing with a panel of nine SARS-CoV-2 viral variant RBD proteins reveal marked differences in the vaccine responses, with low antibody levels and RBD-ACE2 blocking activity stimulated by the Sinopharm and Sputnik V vaccines in comparison to the AstraZeneca or Pfizer/BioNTech vaccines. The Alpha variant caused 97% of infections in Mongolia in June and early July 2021. Individuals who recover from SARS-CoV-2 infection after vaccination achieve high antibody titers in most cases. These data suggest that public health interventions such as vaccine boosting, potentially with more potent vaccine types, may be needed to control the COVID-19 pandemic in Mongolia and worldwide.

Clinical experience with therapeutic vaccines designed for patients with hepatitis.

Franciscan missionary Giovanni Di Plano Carpini traveled in 1245 to a country named Yeke Tartar, to visit a certain man called Genghis Khan. His journey's report narrated peculiar dietary habits of the locals: "they eat anything, even lice". Little that Carpini knew, he had actually documented the earliest known to us record of oral vaccination against blood-borne infections - an approach that is still used occasionally in the present-day Mongolia for therapy of hepatitis. Currently, efforts aimed at developing therapeutic hepatitis vaccines have switched to more palatable path, but we may still benefit from the insight of medieval Mongols. This review provides an update on development of hepatitis B and C vaccines as related to immunotherapy of hepatitis. Immune therapy is a fast-moving field but the results so far failed to pitch woo. Current trends in research on therapeutic vaccine candidates and liver immunology are discussed. We subscribe to the idea that viral hepatitis is essentially an autoimmune disease generating immune-mediated liver damage. Therapeutic vaccines need to be designed in such a way that self-destructive immunity of the host is targeted not the virus, which is not cytopathic.

Prevalence and genotype distribution of hepatitis C virus among apparently healthy individuals in Mongolia: a population-based nationwide study.

BACKGROUND AND AIMS: Hepatitis C virus (HCV) is one of the major causes of liver cirrhosis and hepatocellular carcinoma (HCC) in Mongolia. However, there are no data concerning nationwide prevalence of HCV infection in Mongolia. We intended to investigate the population-based prevalence of HCV infection and genotype distribution among 1512 apparently healthy individuals in this country. METHODS: Between April 2003 and December 2005, sera from 1512 residents of Ulaanbaatar and 12 provinces were collected by two-stage cluster random sampling, and anti-HCV was tested. Anti-HCV-positive samples were tested for HCV RNA by reverse transcription polymerase chain reaction, and HCV genotype was determined. RESULTS: The mean age of the subjects was 46.2+/-17.8 years, and 812 (53.7%) were male. Overall, the prevalence of anti-HCV was 15.6% (236/1512) and HCV RNA was detected in 167 subjects (11.0%), with the most common genotype being 1b (165/167, 98.8%). When the HCV RNA-positive subjects were categorized by decade of age, the prevalence in each age group was as follows: 2.5% in subjects /=61 years of age. The seroprevalence of anti-HCV in a risk group, nurses, was not significantly different from the general population in each decade of age (P>0.05). CONCLUSIONS: Approximately 11.0% of apparently healthy population had detectable HCV RNA in Mongolia, and the predominant genotype of HCV was 1b. Preventive and therapeutic strategies for chronic hepatitis C are urgently warranted in this HCV-endemic area.