Safety and immunogenicity evaluation of inactivated whole-virus-SARS-COV-2 as emerging vaccine development in Egypt

Investigation of the vaccine potential of an in silico designed FepA peptide vaccine against Shigella flexneri in mice model

Background

Shigellosis is one of the significant causes of diarrhea in Bangladesh. It is a global health problem; approximately 1.3 million people die yearly from Shigellosis. The current treatment method, using different antibiotics against Shigellosis is ineffective. Moreover, it becomes a worrying situation due to the emergence of antibiotic-resistant pathogenic microbes responsible for these diarrheal diseases.

Methodology

Previous immunoinformatics study predicted a potential peptide from the Ferric enterobactin protein (FepA) of Shigella spp. In this study, we have chemically synthesized the FepA peptide. As a highly immunogenic, FepA peptide conjugated with KLH has been tested in mice model with complete and incomplete adjuvants as a vaccine candidate.

Results

Immunological analysis showed that all vaccinated mice were immunologically boosted, which was statistically significant (P-value 0.0325) compared to control mice. Immunological analysis for bacterial neutralization test result was also statistically significant (P-value 0.0468), where each ELISA plate was coated with 1 × 107S. flexneri cells. The Challenge test with 1 × 1012S. flexneri cells to each vaccinated and controlled mice showed that 37.5 % of control (non-vaccinated) mice died within seven days after the challenge was given while 100 % of vaccinated mice remained strong and stout. The analyses of the post-challenge weight loss of the mice were also significant (P-value 0.0367) as the weight loss percentage in control mice was much higher than in the vaccinated mice. The pathological and phenotypic appearances of vaccinated mice were also clearly differentiable compared with control mice. Thus all these immunological analysis and pathological appearances directly supported our FepA peptide as a potential immune booster.

Conclusion

This study provides evidence that the FepA peptide is a highly immunogenic vaccine candidate against S. flexneri. Therefore, these findings inspire future trials for the evaluation of the suitability of this vaccine candidate against Shigellosis.

Exploring the reported adverse effects of COVID-19 vaccines among vaccinated Arab populations: a multi-national survey study

The coronavirus disease 2019 (COVID-19) pandemic has been a major challenge worldwide for the past years with high morbidity and mortality rates. While vaccination was the cornerstone to control the pandemic and disease spread, concerns regarding safety and adverse events (AEs) have been raised lately. A cross-sectional study was conducted between January 1st and January 22nd, 2022, in six Arabic countries namely Saudi Arabia, Egypt, Syria, Libya, Iraq, and Algeria. We utilized a self-administered questionnaire validated in Arabic which encompassed two main parts. The first was regarding sociodemographic data while the second was about COVID-19 vaccination history, types, doses, and experienced AEs. A multistage sampling was employed in each country, involving the random selection of three governorates from each country, followed by the selection of one urban area and one rural area from each governorate. We included the responses of 1564 participants. The most common AEs after the first and second doses were local AEs (67.9% and 46.6%, respectively) followed by bone pain and myalgia (37.6% and 31.8%, respectively). After the third dose, the most common AEs were local AEs (45.7%) and fever (32.4%). Johnson and Johnson, Sputnik Light, and Moderna vaccines showed the highest frequency of AEs. Factors associated with AEs after the first dose included an increase in age (aOR of 61-75 years compared to the 12-18 years group: 2.60, 95% CI: 1.59-4.25, p = 0.001) and male gender (OR: 0.72, 95% CI: 0.63-0.82, p < 0.001). The cumulative post-vaccination COVID-19 disease was reported with Sinovac (16.1%), Sinopharm (15.8%), and Johnson and Johnson (14.9) vaccines. History of pre-vaccination SARS-CoV-2 infection significantly increases the risk of post-vaccination COVID-19 after the first, second, and booster doses (OR: 3.09, CI: 1.9-5.07, p < 0.0001; OR: 2.56, CI: 1.89-3.47, p < 0.0001; and OR: 2.94, CI: 1.6-5.39, p = 0.0005 respectively). In conclusion, AEs were common among our participants, especially local AEs. Further extensive studies are needed to generate more generalizable data regarding the safety of different vaccines.

Advances in the design and development of SARS-CoV-2 vaccines

Since the end of 2019, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The RNA genome of SARS-CoV-2, which is highly infectious and prone to rapid mutation, encodes both structural and nonstructural proteins. Vaccination is currently the only effective method to prevent COVID-19, and structural proteins are critical targets for vaccine development. Currently, many vaccines are in clinical trials or are already on the market. This review highlights ongoing advances in the design of prophylactic or therapeutic vaccines against COVID-19, including viral vector vaccines, DNA vaccines, RNA vaccines, live-attenuated vaccines, inactivated virus vaccines, recombinant protein vaccines and bionic nanoparticle vaccines. In addition to traditional inactivated virus vaccines, some novel vaccines based on viral vectors, nanoscience and synthetic biology also play important roles in combating COVID-19. However, many challenges persist in ongoing clinical trials.