Assessment of early and post COVID-19 vaccination antibody response in healthcare workers: a multicentre cross-sectional study on inactivated, mRNA and vector-based vaccines.

In this multicentre study, we compared the status of antibody production in healthcare personnel (HCP) before and after vaccination using different brands of COVID-19 vaccines between March 2021 and September 2021. Out of a total of 962 HCP enrolled in our study, the antibody against the S1 domain of SARS-CoV-2 was detected in 48.3%, 95.5% and 96.2% of them before, after the first and the second doses of the vaccines, respectively. Our results showed post-vaccination infection in 3.7% and 5.9% of the individuals after the first and second doses of vaccines, respectively. The infection was significantly lower in HCP who presented higher antibody titres before the vaccination. Although types of vaccines did not show a significant difference in the infection rate, a lower infection rate was recorded for AstraZeneca after the second vaccination course. This rate was equal among individuals receiving a second dose of Sinopharm and Sputnik. Vaccine-related side effects were more frequent among AstraZeneca recipients after the first dose and among Sputnik recipients after the second dose. In conclusion, our results showed diversity among different brands of COVID-19 vaccines; however, it seems that two doses of the vaccines could induce an antibody response in most of HCP. The induced immunity could persist for 3-5 months after the second vaccination course.

New generation of viral nanoparticles for targeted drug delivery in cancer therapy.

Nanoscale engineering is one of the novel methods to cure multitudes of diseases, such as types of cancers, neurological disorders, and infectious illnesses. Viruses can play a vital role in nanoscale engineering due to their specific properties like minuscule size, high stability in different body conditions, and large-scale production. Viral-like particles (VLPs) as specific nanoscale scaffolds can encapsulate a wide range of cargos, including nucleic acids, proteins, peptides, and drugs. The Exterior portion of VLPs can be changed by genetical or chemical conjugation as well as targeting ligands or peptides. The aforementioned features of VLPs can be used in several applications, such as drug delivery, bioimaging, tissue engineering, vaccine production, and disease detection. This review article attempts to investigate appearance characteristics, modification strategies, and manufacturing methods of VLPs. Additionally, drug delivery to cancer cells as one of the VLPs applications along with different cellular uptake mechanisms of VLPs by cancer cells are chosen for investigation. This review also tries to gather most of the recent studies of drug delivery to cancer cells by VLPs.

COVID-19 Mortality in Children: A Referral Center Experience from Iran (Mofid Children's Hospital, Tehran, Iran).

Background: The novel coronavirus disease 2019 (COVID-19) started in Wuhan, China, in December 2019. It spread widely around the world and was described as a pandemic by the World Health Organization (WHO). The knowledge regarding the mortality rate and risk factors of COVID-19 among the pediatric population is lacking. In this regard, we aimed to report the clinical and laboratory characteristics of deceased pediatric patients with SARS-CoV-2 infection. Method: This cross-sectional study was conducted in Mofid Children's Hospital, Tehran, Iran, from February 2020 to April 2021. Recorded documents of 59 pediatric patients (under 18 years old) assumed to have COVID-19 who had died in the COVID-19 ward and COVID-19 intensive care unit (ICU) were retrospectively evaluated. All statistical analyses were performed using SPSS software (v. 26.0, Chicago, IL). A P value of less than 0.05 was considered statistically significant. Results: From 711 COVID-19 definite and suspected patients, 59 children died. Of these deceased pediatric patients, 34 were boys (57.62%) and 25 were girls (42.37%), with a total mean age of 5.6 years. The median length of stay in the hospital was 10 days (range 1-215). 91.52% had underlying comorbidities of which neurological diseases accounted for the largest share. 54 patients were admitted to the ICU and 83.05% of them had intubation during their hospitalization. In addition, the most common reasons for death in our study were related to respiratory and multiorgan failure. Conclusion: According to our knowledge, we are the first team to report such a thorough study in the field of COVID-19 pediatric mortality in Iran. Mortality was observed in all age groups of children, especially in those with previous comorbidities, specifically neurological disease. Abnormally elevated tests of ESR, CRP, LDH, AST, and ALT as well as the presence of proteinuria and hematuria were found in more than 50% of patients in our investigations, and ICU admission between both definite and suspected groups had significant differences, so monitoring and considering these factors may help to control and reduce the progression of the disease to death.