RESUMEN
Background: A nationwide vaccination program against coronavirus disease 2019 (COVID-19) was started in Mongolia 4 months after the first local transmission, which occurred in November 2020. Previous studies have reported that two doses of COVID-19 vaccine result in increased antibody against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A study was conducted in Mongolia 2 weeks after the second vaccine dose. In the present study, the serum levels of antibodies of individuals 6 months after natural SARS-CoV-2 infection were compared with those of individuals who had not been infected or had been infected but had received two doses of vaccine, including BNT162b2, ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BBIBP-CorV, which were used for COVID-19 in Mongolia. Methods: Of the 450 participants in this study, 237 (52.66%) were female and 213 (47.33%) were male. Four hundred people with or without SARS-CoV-2 infection who received two doses of 4 different COVID-19 vaccine participated in the vaccine groups and vaccine plus SARS-CoV-2 infection groups (50 in each group) and 50 individuals previously infected with SARS-CoV-2 participated in the unvaccinated group. Total antibody against SARS-CoV-2 infection, anti-SARS-CoV-2 N and S protein human IgG, and antibody inhibiting RBD-ACE2 binding were tested. Results: In the BNT162b2 vaccine group, total antibody against SARS-CoV-2 remained constant until 6 months, while the other vaccine groups showed a significant decrease, as compared to the unvaccinated group. The level of anti-SARS-CoV-2 S-RBD protein IgG was significantly increased in the ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BNT162b2 vaccines groups as compared to the unvaccinated group. Participants in the BNT162b2 vaccine group had higher ACE2 inhibition efficiency compared to the other vaccine groups as well as the unvaccinated group. Conclusions: The BNT162b2 vaccine showed the highest level of antibody against SARS-CoV-2, followed by the BBIBP-CorV, Gam-COVID-Vac, and ChAdOx1 n-CoV-19 vaccines. The level of antibodies was increased in people infected with SARS-CoV-2 after vaccination, as compared to uninfected but vaccinated individuals.
RESUMEN
BACKGROUND: Diarrheal disease is one of the leading causes of illness and death in young children in the world, especially the developing countries. Diarrheal disease results in about half a million childhood death per year, ranking second among all causes worldwide. Diarrheal disease due to rotavirus infection is currently the most common cause of severe diarrhea in infants and young children worldwide. Rotavirus immunization of infants is a safe and effective public health intervention for rotavirus infection control and expected to lead to a reduction of childhood morbidity and mortality. METHODS: We conducted hospital-based surveillance at two representative hospitals in Mongolia to estimate the burden of hospitalizations for rotavirus diarrhea among children agedâ¯<5â¯years and to describe strain distribution patterns during 6-year study period. Fecal specimens were tested by rotavirus antigen detection enzyme immunoassay (EIA). Specimens that tested positive for rotavirus were further characterized to determine the genotype of strains by reverse-transcriptase polymerase chain reaction. RESULTS: Between April 2009 and March 2016, among 7076 eligible children with diarrhea 6078 patients were enrolled nationally. Forty-six percent (2794/6078) of EIA a specimens were positive for rotavirus. Ninety-three percent (5649/6078) of hospitalizations for diarrhea involved children less than 2â¯years. No deaths were recorded due to rotavirus diarrhea. The most common genotype was G3P [8] (47.7%) followed by G9P [6] (14.4%), G2P [4] (12%), and G9P [8] (7.1%). CONCLUSIONS: This study found a relatively high prevalence of severe rotavirus-associated diarrhea disease in Mongolia and infants were the most affected. It highlights the urgent need for introduction of rotavirus vaccine into the national immunization program. Continued surveillance is crucial and pre-vaccine introduction rotavirus genotype patterns in Mongolia are valuable and can be followed post-introduction to assess vaccine impact.
