Anti-SARS-CoV-2 IgG Antibodies Post-COVID-19 or Post-Vaccination in Libyan Population: Comparison of Four Vaccines.

Measurement of strength and durability of SARS-COV-2 antibody response is important to understand the waning dynamics of immune response to both vaccines and infection. The study aimed to evaluate the level of IgG antibodies against SARS-CoV-2 and their persistence in recovered, naïve, and vaccinated individuals. We investigated anti-spike RBD IgG antibody responses in 10,000 individuals, both following infection with SARS-CoV-2 and immunization with SARS-COV-2 AstraZeneca, Sputnik V, Sinopharm, and Sinovac. The mean levels of anti-spike IgG antibodies were higher in vaccinated participants with prior COVID-19 than in individuals without prior COVID-19. Overall, antibody titers in recovered vaccinee and naïve vaccinee persisted beyond 20 weeks. Vaccination with adenoviral-vector vaccines (AstraZeneca and Sputnik V) generates higher antibody titers than with killed virus vaccine (Sinopharm and Sinovac). Approximately two-thirds of asymptomatic unvaccinated individuals had developed virus-specific antibodies. A single dose of vaccine is likely to provide greater protection against SARS-CoV-2 infection in individuals with apparent prior SARS-CoV-2 infection, than in SARS-CoV-2-naive individuals. In addition, the high number of seropositivity among asymptomatic unvaccinated individuals showed that the number of infections are probably highly underestimated. Those vaccinated with inactivated vaccine may require more frequent boosters than those vaccinated with adenoviral vaccine. These findings are important for formulating public health vaccination strategies during COVID-19 pandemic.

Hospitalization among vaccines for SARS-CoV-2 breakthrough infection after dose sparing strategies in Libya: A cohort study.

SARS-CoV-2 infection is widely spread over people, from youth to the elderly. Vaccination against SARS-CoV-2 is an essential preventive measure to help end the SARS-CoV-2 pandemic. A multi-center retrospective cohort study was conducted on patients in Libya who had received single-dose licensed three different types of vaccines (Oxford/AstraZeneca, CoronaVac, or Sputnik-V) and were admitted to healthcare centers with SARS-CoV-2 infection from 30th April to 15th July 2021. In this study, the number of people infected with SARS-COV-2 and the mortality rate from daily reports issued by the National Centers for Disease Control of Libya (NCDC) were collected. Approximately 445000 single doses of the SARS-COV-2 vaccine were administered in Libya from April to July 2021. In corresponding, 39996 people were infected during this period. It has been found that among the people who did not receive any vaccine, the number of patients infected by SARS-COV-2 and admitted to the healthcare centers, and died was (N = 3176 patients (7.94%), and 266 (7.10%) respectively). Compared to 43 (0.10%) of those admitted to healthcare centers who had taken a single dose from one of the licensed vaccines, of which 8 patients (0.02%) died during this period. The documented 23 patients were those who admitted to healthcare centers and got vaccinated with the CoronaVac (Sinovac) vaccine. Fourteen patients received Oxford/AstraZeneca. Only 2 patients received the Sputnik V vaccine. Of the breakthrough infection cases reviewed, 8 patients died. No deaths due to breakthrough infection among Sputnik V vaccinated patients were reported. In conclusion, a single dose of the three different types of the vaccine has significantly reduced virus interpersonal transmission and also showed a decrease in the mortality rate until the tenth week in Libya. The present study demonstrates the extent of the remarkable success of the early rollout of the coronavirus national vaccination campaign.

Correlation between maternal and fetal umbilical cord blood lead concentrations in Libya.

Background: People are exposed to lead from car exhaust fumes (leaded petrol), lead-based paints, plumbing systems, cigarette smoking, contaminated soil and dust, foods grown in polluted areas, and water sources. Among the vulnerable subpopulations are pregnant women, fetuses and infants. Aims: To estimate and correlate maternal and neonatal blood lead levels and compare these between neonates and their mothers in Tripoli and Ghadames. Methods: In this cross-sectional study, blood was collected from 120 and 116 mothers and their neonates from Tripoli and Ghadames, respectively. Lead levels were determined using atomic absorption spectrophotometry. A simple questionnaire was filled by the participants using face-to face interview. Data were analysed using SPSS version 20.0 and Excel. Results: Mean blood and umbilical cord lead levels were 6.83 (standard deviation 4.96) and 6.05 (4.89) µg/dl in mothers and neonates from Tripoli, respectively, and 5.91 (4.02) and 4.54 (4.09) µg/dl from Ghadames. There was no significant difference in blood lead level between mothers from Tripoli and Ghadames. However, there was a significant correlation between maternal blood and umbilical cord blood in Tripoli and Ghadames. Linear regression revealed that neonatal umbilical cord blood lead levels reflected the levels in maternal blood. Blood lead in this study was higher than that reported in industrialized western countries. Conclusion: We detected moderate blood lead levels among pregnant women in Tripoli and Ghadames. It is important to detect the source of lead in the Libyan population to treat this problem effectively.