Launching COVID-19 vaccination in Saudi Arabia: Lessons learned, and the way forward.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARSCoV- 2) emerged in Wuhan City, China. The SARS-CoV-2 crossed borders and quickly transformed into a "Public health emergency of international concern". Countries around the globe are in the race to achieve herd immunity. We describe the steps taken by Saudi Arabia to achieve this goal.

Orthodontic treatment need among young Saudis attending public versus private dental practices in Riyadh.

OBJECTIVE: To assess and compare the severity of malocclusion and orthodontic treatment need among young Saudis receiving free treatment at public dental practices versus those paying for treatment at private practices. MATERIALS AND METHODS: This retrospective study evaluated the records of 300 patients (179 females, 121 males; age 13-21 years) treated at orthodontic clinics from 2013 through 2015. The public sample was selected from orthodontic clinics at the College of Dentistry, King Saud University (KSU); the private sample was selected from five private orthodontic clinics in Riyadh, Saudi Arabia. The records were examined for the severity of malocclusion and for orthodontic treatment need using the Dental Health Component of the Index of Orthodontic Treatment Need. The prevalence of each occlusal discrepancy and the Dental Health Component grade were recorded. The severity of malocclusion and orthodontic treatment need were compared between practice types, age groups, and sexes with the chi-square test. RESULTS: Displacement, increased overjet, and Class II and III malocclusion were the most common orthodontic problems in this study. Patients attending public clinics at KSU generally had more severe malocclusion than the patients attending private clinics. Seventy-seven percent of orthodontically treated patients at KSU clinics were in great need of treatment, compared with 58.5% of patients treated at private clinics (P=0.003). Among the patients with great treatment need, approximately 62% of male patients and 70% of patients ≤16 years of age were treated at KSU clinics, compared with 38% and 48%, respectively, treated at private clinics (P<0.0001). CONCLUSION: Young Saudis receiving free orthodontic treatment at public clinics at KSU had more severe malocclusion with greater need of orthodontic treatment than the patients paying for treatment at private clinics.

Among 45 variants in 11 genes, HDM2 promoter polymorphisms emerge as new candidate biomarker associated with radiation toxicity.

Due to individual variations in radiosensitivity, biomarkers are needed to tailor radiation treatment to cancer patients. Since single nucleotide polymorphisms (SNPs) are frequent in human, we hypothesized that SNPs in genes that mitigate the radiation response are associated with radiotoxicity, in particular late complications to radiotherapy and could be used as genetic biomarkers for radiation sensitivity. A total of 155 patients with nasopharyngeal cancer were included in the study. Normal tissue fibrosis was scored using RTOG/EORTC grading system. Eleven candidate genes (ATM, XRCC1, XRCC3, XRCC4, XRCC5, PRKDC, LIG4, TP53, HDM2, CDKN1A, TGFB1) were selected for their presumed influence on radiosensitivity. Forty-five SNPs (12 primary and 33 neighboring) were genotyped by direct sequencing of genomic DNA. Patients with severe fibrosis (cases, G3-4, n = 48) were compared to controls (G0-2, n = 107). Results showed statistically significant (P < 0.05) association with radiation complications for six SNPs (ATM G/A rs1801516, HDM2 promoter T/G rs2279744 and T/A rs1196333, XRCC1 G/A rs25487, XRCC5 T/C rs1051677 and TGFB1 C/T rs1800469). We conclude that these six SNPs are candidate genetic biomarkers for radiosensitivity in our patients that have cumulative effects as patients with severe fibrosis harbored significantly higher number of risk alleles than the controls (P < 0.001). Larger cohort, independent replication of these findings and genome-wide association studies are required to confirm these results in order for SNPs to be used as biomarkers to individualize radiotherapy on genetic basis.

Involvement of single-nucleotide polymorphisms in predisposition to head and neck cancer in Saudi Arabia.

AIM: Individuals differ in their inherited tendency to develop cancer. This has been suggested to be due to genetic variations between individuals. Single-nucleotide polymorphisms (SNPs) are the most common form of genetic variations found in the human population. The aim of this study was to investigate the association between 10 SNPs in genes involved in cell cycle control and DNA repair (p21 C31A, p53 G72C, ATM G1853A, XRCC1 G399A, XRCC3 C241T, Ku80 A2790G, DNA Ligase IV C9T, DNA-PKcs A3434G, TGF-beta T10C, MDM2 promoter T309G) and the risk to develop head and neck cancer. MATERIALS AND METHODS: A cohort of 407 individuals (156 cancer patients and 251 controls) was included. DNA was extracted from peripheral blood. SNPs were genotyped by direct sequencing. RESULTS: Data showed significant allelic associations for p21 C31A (p=0.04; odds ratio [OR]=1.44; confidence interval [CI]: 1.02-2.03), Ku80 A2790G (p=0.04; OR=1.5; CI: 1.01-2.23), and MDM2 T309G (p=0.0003; OR=0.58; CI: 0.43-0.78) and head and neck cancer occurrence. Both cancer cases and controls were in Hardy-Weinberg equilibrium. CONCLUSION: SNPs can be associated with head and neck cancer in the Saudi population. The p21 C31A, Ku80 A2790G, and MDM2 T309G SNPs could be used as genetic biomarkers to screen individuals at high cancer risk.