Immunogenicity and real-world effectiveness of COVID-19 vaccines in Lebanon: Insights from primary and booster schemes, variants, infections, and hospitalization.

In this study, we conducted a case-control investigation to assess the immunogenicity and effectiveness of primary and first booster homologous and heterologous COVID-19 vaccination regimens against infection and hospitalization, targeting variants circulating in Lebanon during 2021-2022. The study population comprised active Lebanese military personnel between February 2021 and September 2022. Vaccine effectiveness (VE) against laboratory-confirmed SARS-CoV-2 infection and associated hospitalization was retrospectively determined during different variant-predominant periods using a case-control study design. Vaccines developed by Sinopharm, Pfizer, and AstraZeneca as well as Sputnik V were analyzed. Prospective assessment of humoral immune response, which was measured based on the SARS-CoV-2 antispike receptor binding domain IgG titer, was performed post vaccination at various time points, focusing on Sinopharm and Pfizer vaccines. Statistical analyses were performed using IBM SPSS and GraphPad Prism. COVID-19 VE remained consistently high before the emergence of the Omicron variant, with lower estimates during the Delta wave than those during the Alpha wave for primary vaccination schemes. However, vaccines continued to offer significant protection against infection. VE estimates consistently decreased for the Omicron variant across post-vaccination timeframes and schemes. VE against hospitalization declined over time and was influenced by the variant. No breakthrough infections progressed to critical or fatal COVID-19. Immunogenicity analysis revealed that the homologous Pfizer regimen elicited a stronger humoral response than Sinopharm, while a heterologous Sinopharm/Pfizer regimen yielded comparable results to the Pfizer regimen. Over time, both Sinopharm's and Pfizer's primary vaccination schemes exhibited decreased humoral immunity titers, with Pfizer being a more effective booster than Sinopharm. This study, focusing on healthy young adults, provides insights into VE during different pandemic waves. Continuous research and monitoring are essential for understanding vaccine-mediated immune responses under evolving circumstances.

[Atrioventricular septal defect characteristics in infants with and without Down's syndrome: a Lebanese study]. / Caractéristiques du canal atrioventriculaire chez les enfants avec et sans syndrome de Down: étude libanaise.

OBJECTIVES: Analyze the demographic and clinical characteristics of complete atrioventricular septal defect (AVSD), its association with Down's syndrome, with other cardiac and extra-cardiac anomalies, and finally the impact of consanguineous marriages on the incidence of AVSD. PATIENTS & METHODS: The sample consisted of 2195 consecutive patients with congenital heart defect, entered in the National Register of Paediatric and Congenital Heart Disease, Lebanese Society of Cardiology, Beirut, between Jan 1999 and Dec 2007. 120 patients with AVSD were analyzed. The gathered data included age, sex, type of AVSD, mother's age, 1st and 2nd degree cousins, and other associated cardiac or extra-cardiac anomalies. RESULTS: AVSD was diagnosed in 5.5% of all patients with congenital heart disease, with 81.7% (n = 98) being complete AVSD. Male sex was predominant (58%). More than half (57.5%) were also diagnosed with Down's syndrome. The mean maternal age was 30.4 years (+/- 4.7 years) and consanguinity found in 16.7% of the cases. Cardiac and extra-cardiac anomalies (all in the esophagus and intestine) were associated in 15% and 6.7% respectively. Complete AVSD was significantly associated with Down's syndrome: 94% of patients with Down's syndrome had a complete AVSD. Digestive anomalies were also significantly more frequent with Down's syndrome (10% versus 2%, p = 0.02). Other cardiac anomalies, however, were less frequent with Down's syndrome (33% versus 7.7%, p = 0.02). CONCLUSION: Down's syndrome is more frequently associated with isolated and complete AVSD. Other anomalies may complicate the management of these patients. The cause of this probable genetic anomaly is still debated.