ABSTRACT
Since the emergence of COVID 19, the authentic SARS-CoV-2 has evolved into a range of novel variants that are of more global concern. In late November 2021, the Omicron (lineage B.1.1.529) variant was identified as a new variant and considered as the fifth variant of concern. Omicron harbors a genetic profile that is exceedingly unusual, with a huge number of mutations. Above thirty mutations are localized in the S protein, while some are found in other structural and non-structural proteins. Half of the mutations in the S protein are in the RBD, which is a major target of antibodies, showing that Omicron mutations may affect antibody binding affinity to the S protein. The Omicron variant has been found to result in immune escape, therapeutic or vaccine escape, as well as increased transmissibility and reinfection risk, explaining its rapid international spread that sparks a global alarm even more serious than the previously reported variants. Omicron has the capability to bypass at least some of the multi-faceted immune responses induced by prior infection or vaccination. It is shown to extensively escape neutralizing antibodies while evading cell mediated immune defense to a lesser extent. The efficacy of COVID 19 vaccines against Omicron variant is decreased with primary vaccination, showing that the vaccine is less efficient in preventing Omicron infections. However, after receiving a booster vaccine dose, the immunological response to Omicron significantly improved and hold promising results. Despite the mild nature of the disease in most vaccinated people, the rapid spread of Omicron, as well as the increased risk of re-infection, poses yet another major public health concern. Therefore, effort should be devoted to maintaining the existing COVID 19 preventive measures as well as developing new vaccination strategies in order to control the fast dissemination of Omicron.
ABSTRACT
BACKGROUND: Cancer patients are classified as being at high risk of contracting COVID-19 infection, hospitalization, and death and were recommended to have early access to the limited COVID-19 vaccine. However, there are limited studies on the knowledge and acceptance of the COVID-19 vaccine among cancer patients. Therefore, this study aimed at assessing the awareness, readiness, and associated factors among cancer patients. METHODS: Institution-based cross-sectional study was conducted on 422 cancer patients from May to August, 2021. A structured interviewer-administered questionnaire was used to collect primary data. A systematic random sampling technique was used to select study participants. Descriptive statistics and binary logistic regression followed by multivariable analysis were performed to investigate the independent association of factors with the outcome variable. Finally, statistical significance was declared at P <0.05 using AOR and 95% CI. RESULTS: From the 422 cancer patients who participated, 77 (18.2%) had a history of COVID-19 infection, and 224 (55%) believe that the cancer disease will not make them more vulnerable to be infected by COVID-19. Accordingly, younger age (18-30 years) (AOR = 2.73: 95% CI: 0.18, 4.51), female (AOR = 6.4: 95% CI: 0.7, 13.8), having information about COVID-19 vaccine (AOR = 6.9: 95% CI: 3.1, 15.2), COVID-19 infection history (AOR = 6.0: 95% CI: 2.5, 11.8), duration since cancer diagnosis (≥10 years) (AOR= 6.2: 95% CI: 2.6, 14.7), and belief about the likelihood of dying of COVID-19 infection (AOR = 3.05: 95% CI: 1.03, 4.05) were the independent predictors of the likelihood of receiving COVID-19 vaccine among cancer patients. CONCLUSION: This study has found significant cancer patients with poor knowledge about the vaccine, and the percentage of both the first and second round of COVID-19 vaccination was small. Therefore, information communication with cancer patients and oncologists about the COVID-19 vaccine may help to decrease vaccine hesitancy.