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COVID-19 Vaccine Development and Applications
Published in Yashwant V. Pathak, Gene Delivery Systems, 2022
Previous research experiences with SARS-CoV and MERS-CoV have laid the groundwork for accelerated SARS-CoV-2 vaccine development. Many research groups and companies are undertaking efforts to develop an effective vaccine against SARS‑CoV‑2 all over the world and speeding up all the usual phases needed to develop and test a vaccine in humans. At present, there are more than 290 vaccine candidates under development, with a number of these already approved for emergency use. These approved vaccine candidates in clinical trials have all shown promising immunogenicity with varying degrees of protective efficacy and an acceptable safety profile, but further investigation on immunization schedules is required. However, these different vaccines have not been studied head-to-head, and thus, comparative efficacy is uncertain. Currently, the vaccine supply is not sufficient to meet worldwide demand; many nations are asking for dose-sparing strategies without impacting effectiveness. Several governments have made up-front payments to secure a number of doses of the vaccines under development. Further development of multiple vaccine candidates using different vaccine delivery systems such as nanoparticles is crucial so that the final vaccine products can be readily produced and formulated for rapid deployment and mass vaccination across the globe. Even though there are still many challenges and unanswered questions regarding anti-SARS-CoV-2 immunity, potential mutations of SARS-CoV-2, and seasonal recurrences, the remarkable breakthroughs in COVID-19 vaccine development have offered hope to return to a pre-pandemic normality.
Spray-freeze-dried Particles as Novel Delivery Systems for Vaccines and Active Pharmaceutical Ingredients
Published in S. Padma Ishwarya, Spray-Freeze-Drying of Foods and Bioproducts, 2022
Apart from insulin, most of the inactivated vaccines including the subunit, split, virosome and whole inactivated virus (WIV) are administered through intramuscular or subcutaneous route. These conventional routes of vaccination suffer from various limitations. Firstly, these demand several resources such as syringes, sterile needles and the assistance of healthcare professionals. This increases the cost of vaccination and the likelihood of needle stick injuries. Fear of needles and pain reduce the preference of vaccines administered by intramuscular and subcutaneous routes (Amorij et al., 2010). Many people are vulnerable to infection even after vaccination through conventional routes. This can be overcome by eliciting a strong immune response at the entry site of the virus, which is possible with the pulmonary route of vaccine administration as it is capable of neutralizing the virus in the upper respiratory tract. Vaccine stability is yet another parameter of importance. The currently available vaccines administered through conventional route, for instance, the influenza vaccines and COVID-19 vaccines require refrigerated storage and transport. All the above factors necessitate the development of vaccines that are shelf-stable under ambient conditions and can be self-administered through a non-parenteral route, which would initiate effective immune response at a relatively low dose (Murugappan, 2014). Thus, a vaccine administered through non-conventional routes is perceived as an effective approach to simplify mass vaccination drives mandated during a pandemic situation.
Modeling Virus Dynamics in Time and Space
Published in Ranjit Kumar Upadhyay, Satteluri R. K. Iyengar, Spatial Dynamics and Pattern Formation in Biological Populations, 2021
Ranjit Kumar Upadhyay, Satteluri R. K. Iyengar
The authors determined the first excited mode of oscillations n, just by expressing g(k) in terms of the number of contacts β, between susceptible and infected populations per unit time. They concluded the following: (i) For higher values of the bifurcation parameter β, the spatial model system destabilizes as compared to the temporal system. (ii) With an increase in the rate of vaccination, a higher value of β destabilizes the system in the absence of diffusion. (iii) In the presence of diffusion, a lower value of β destabilizes the system with the increase in the rate of vaccination. Therefore, the contact parameter β plays the main role in the spread of disease. Its value must not exceed the bifurcation point to make the system unstable. (iv) Diffusion in the system helps in stabilizing the system, thus reducing the chances of an outbreak of disease beyond control. (v) Measure of vaccination efficacy is essential before the implementation of a mass vaccination program.
A systematic review of mathematical models of the Ebola virus disease
Published in International Journal of Modelling and Simulation, 2022
Suliman Jamiel M. Abdalla, Faraimunashe Chirove, Keshlan S. Govinder
The impact of ring, mass, and voluntary vaccination strategies were explored, and valuable insights were provided. Brettin et al [97]. concluded that a voluntary vaccination might be able to eradicate EVD, particularly when added to other control measures. Nguyen et al [46]. found that mass vaccination of 85% coverage can eradicate the disease if it was launched between five months before and one week after the outbreak. Merler et al [93]. concluded that a ring vaccination to be effective in containing an epidemic up to the value of R0 = 1.6 This figure was increased when other control measures were added. Kucharski et al [94]. found that when an epidemic is less severe, a ring vaccination could eradicate the outbreak. Camacho et al [88]. suggested that when a vaccination trial was started at an earlier time, the probability of eliminating the disease in vaccinated groups increased. The studies [88,94,97], however, contained some limitations. Brettin et al [97]. assumed the population to be rational enough to decide to be vaccinated voluntarily and assumed the population to be well informed about the risk of the disease and the direct and indirect cost of vaccinations. Kucharski et al [94]. did not account for different possible immunity periods that the Merck rVSV-ZEBOV vaccine might have [105]. Camacho et al [88]. did not account for any logistical constraints that may affect the feasibility of the vaccination trial in the studied areas.
Optimizing patient flow, capacity, and performance of COVID-19 vaccination clinics
Published in IISE Transactions on Healthcare Systems Engineering, 2022
Leonardo Valladares, Valentina Nino, Kenneth Martínez, Durward Sobek, David Claudio, Sally Moyce
This study is significant since it presents a model for using industrial engineering tools in planning and improving a mass vaccination event to inform future large-scale vaccination efforts and demonstrates the ability of to support healthcare personnel to increase the performance of the vaccination centers. To the knowledge of the authors, no previous study has applied tools from Industrial Engineering to improve patient flow, capacity, and performance in a COVID-19 walk-through clinic. Due to the improvements identified in this study, it was possible to reduce the duration of the second clinic by 40% while vaccinating almost the same number of patients with no increases in overall staffing.
Gold nanoparticles as radiosensitizer for radiotherapy and diagnosis of COVID-19: A review
Published in Nanoscale and Microscale Thermophysical Engineering, 2022
Abdul Khaliq Mokhtar, Norsyahidah Mohd Hidzir, Faizal Mohamed, Irman Abdul Rahman, Syazwani Mohd Fadzil, Afifah Mardhiah Mohamed Radzi, Nur Ain Mohd Radzali
Three circumstances exist for which nanoparticles (mainly AuNP) may be used to resolve the COVID-19 pandemic. First, an accurate and rapid diagnostic detection system (e.g., molecular, antigen, or antibody tests) for tracking contacts, isolating infected individuals, and mitigating the virus spread must be established [172, 173]. Second, therapeutic and clinical interventions can help alleviate the symptoms of the infection and reduce morbidity and mortality brought on by the virus [174, 175]. Third, the formulation of a vaccine will help generate antibodies for mass vaccination to induce herd immunity [176, 177].