Development Of Inactivated Vaccine Research Articles

Inactivated SARS-CoV-2 vaccine candidate immunization on non-human primate animal model: B-cell and T-cell responses immune evaluation

BackgroundSARS-CoV-2 vaccine was proven to be an effective and efficient measure for mitigating pandemic. COVID-19 infection and mortality subsided along with the increaseing COVID-19 vaccination coverage. Vaccine and health resource equity are predominant factors in COVID-19 pandemic management. Vaccine development for Indonesia, aims to ensure a sustainable pandemic control and steady national stability restoration. A decent vaccine must induce immunity against COVID-19 with minimum adverse reaction. Immunogenicity and ability to induce neutralizing antibody evaluation needs to be performed as part of the SARS-CoV-2 inactivated vaccine development from East Java, Indonesia isolate (Vaksin Merah Putih-INAVAC). ObjectiveThis research demonstrated INAVAC performance in inducing the production neutralizing antibody along with its effects on CD4+ and CD8+ cells response in Macaca fascicularis (non-human primate). MethodsTwo dosages of 3 μg and 5 μg were tested, compared to sham (NaCl 0.9%) in 10 Macaca fascicularis (2 injection intramuscular with 14 days interval). All animals were monitored daily for clinical signs. Nasopharyngeal samples were analyzed using qRT-PCR while the serum were tested using ELISA and neutralization assay, whereas PBMCs were flowcytrometrically analyzed to measure CD4+ and CD8+ population. ResultsIt is observed that both vaccine doses could stimulate relatively similar immune response and neutralizing antibody (end GMT post challenge = 905,1), whereas higher CD8+ cells response were reported in the 5 μg group after the 3rd day post-challenge. The dose of vaccine that produce adequate immune cell stimulation with neutralizing antibody induction can be adopted to clinical study, as favorable result of these parameters could predict minimum adverse reaction from inflammation response with balanced immune response. ConclusionsTherefore, it is concluded that Vaksin Merah Putih-INAVAC with 3 μg dose showed a favorable potential to be developed and tested as human vaccine.

Trial Evaluation of Protection and Immunogenicity of Piscine Bivalent Streptococcal Vaccine: From the Lab to the Farms.

Streptococcosis is one of the major diseases that causes devastation to farmed fish, leading to significant economic losses all around the world. Currently, two serotypes of Streptococcus agalactiae, serotype Ia and III, have been identified as virulent strains and major causative agents of the disease in farmed Nile tilapia (Oreochromis niloticus Linn.) in Thailand. Upon inactivated vaccine development, monovalent inactivated whole-cell vaccines demonstrated high specific antibody production against homologous serotypes and limited production with heterologous serotypes. However, for higher efficacy, a bivalent streptococcal vaccine was designed to maximize protective immunity to both serotypes. Interestingly, our bivalent vaccine could successfully induce specific antibody production against both serotypes with similar levels, and the response could extend over the 8 weeks of the experimental period. Evaluation of vaccines in the laboratory scale revealed relative percent survival (RPS) of vaccinated tilapia to serotype Ia (81.2 ± 9.4%) and serotype III (72.2 ± 4.8%), respectively. The efficacy of the bivalent vaccine showed significant RPS higher than the monovalent vaccine (p < 0.05) at 30 days, and the protection of all those vaccines was reduced thereafter. Evaluation of the vaccine in a farm trial in different locations in Thailand revealed the efficacy of the bivalent vaccine in increasing the production yield by greater than 80% in all tested farms in 2015 and 2021. Taken together, this study affirms the efficacy of the bivalent streptococcal vaccine in the prevention of streptococcus disease in Nile tilapia, which could be used in different areas. This vaccine development could be effectively applied in the tilapia culture industry.

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

BackgroundCurrent worldwide pandemic coronavirus disease 2019 (COVID-19) with high numbers of mortality rates and huge economic problems require an urgent demand for safe and effective vaccine development. Inactivated SARS-CoV2 vaccine with alum. Hydroxide can play an important role in reducing the impacts of the COVID-19 pandemic. In this study, vaccine efficacy was evaluated through the detection of the neutralizing antibodies that protect mice from challenge with SARS-CoV 2 3 weeks after the second dose. We conclude that the vaccine described here has safety and desirable properties, and our data support further development and plans for clinical trials.MethodsCharacterized SARS-COV-2 strain, severe acute respiratory syndrome coronavirus 2 isolates (SARS-CoV-2/human/EGY/Egy-SERVAC/2020) with accession numbers; MT981440; MT981439; MT981441; MT974071; MT974069; and MW250352 at GenBank were isolated from Egyptian patients SARS-CoV-2-positive. Development of inactivated vaccine was carried out in a BSL-3 facilities and the immunogenicity was determined in mice at two doses (55 and 100 μg per dose).ResultsThe distinct cytopathic effect induced by SARS-COV-2 propagation on Vero cell monolayers and the viral particles were identified as Coronaviridae by transmission electron microscopy and RT-PCR on infected cells cultures. Immunogenicity of the developed vaccine indicated the high antigen-binding and neutralizing antibody titers, regardless of the dose concentration, with excellent safety profiles and no deaths or clinical symptoms in mice groups. The efficacy of the inactivated vaccine formulation was tested by the wild virus challenge of the vaccinated mice and viral replication detection in lung tissues.ConclusionsVaccinated mice recorded complete protection from challenge infection via inhibition of SARS-COV-2 replication in the lung tissues of mice following virus challenge, regardless of the level of serum neutralizing antibodies. This finding will support future trials for the evaluation of an applicable SARS-CoV-2 vaccine candidate.

Gamma irradiation-mediated inactivation of enveloped viruses with conservation of genome integrity: Potential application for SARS-CoV-2 inactivated vaccine development.

Radiation inactivation of enveloped viruses occurs as the result of damages at the molecular level of their genome. The rapidly emerging and ongoing coronavirus disease 2019 (COVID-19) pneumonia pandemic prompted by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is now a global health crisis and an economic devastation. The readiness of an active and safe vaccine against the COVID-19 has become a race against time in this unqualified global panic caused by this pandemic. In this review, which we hope will be helpful in the current situation of COVID-19, we analyze the potential use of γ-irradiation to inactivate this virus by damaging at the molecular level its genetic material. This inactivation is a vital step towards the design and development of an urgently needed, effective vaccine against this disease.

Preliminary Step towards COVID-19 Inactivated Vaccine Development in Egypt

The current worldwide COVID-19 pandemic is causing severe human health problems, with high mortality rates and huge economic burdens requiring the urgent development of a safe and effective vaccine. Here, preclinical evaluation of an inactivated SARS-CoV-2 vaccine candidate (EgySerVac-20) is reported. Oropharyngeal swabs and nasopharyngeal aspirates obtained from Egyptian patients with laboratory-confirmed SARS-CoV-2 infection were isolated using Vero cells and were then genetically characterized. Vaccine inactivation was performed using diluted formaldehyde, followed by safety testing for the inactivated vaccine. To determine the high humoral immune responses against SARSCOV-2 infection, the safety and capacity of the vaccine prepared with alum adjuvant were tested. The immunogenicity and efficacy of the vaccine candidate was tested in vitro by a neutralization assay and in vivo using mouse models. Our results revealed a cytopathic effect which was observed 48 hours post infection and the viral particles were identified by rRT-PCR as SARS-CoV-2. Propagation of the isolated virus in ten serial passages on the Vero cells yielded a virus titer 7.5 log10 TCID50/ml. Complete inactivation of SARS-CoV-2 was observed at 37°C in 24 hours post treatment by diluted formaldehyde. Inactivated SARS-CoV-2 infected fluid safety was determined by absence of cytopathic effect by repeated passage in Vero cell line, indicating loss of virus infectivity. Virus inactivated by diluted formaldehyde showed no deaths or clinical symptoms in mice groups post intraperitoneal inoculation (0.5ml/mouse). EgySerVac-20 inactivated vaccine has safely induced high levels of neutralizing antibodies titers in mice, where 0.1 ml immunization dose showed protective efficacy against SARS-CoV-2 challenge in mice. This finding will support the future preclinical and clinical trials evaluation for our SARS-CoV-2 vaccine candidate in primates and human, respectively.

Recent Proceedings on Prevalence and Pathogenesis of Streptococcus suis.

Streptococcus suis (S. suis) is an important zoonotic pathogen that causes huge economic losses in the pig industry, as well as severe illness and even death in humans. The outbreak of human infection of S. suis in China in 2005 led to significant human morbidity and death, prompting an increase in global studies of S. suis. In recent years, important advances have been made regarding the etiology, genomics, excavation of virulence genes, and vaccine research in S. suis. A number of countries and regions have identified their predominantly serotypes. The development of genome sequencing technology has laid an important foundation for the study of pathogenic mechanisms. For example, 89K PAI was found in representative virulence strains in China, and several studies have been carried out to confirm multiple genes which carries are closely related to virulence. Also, the functions of some regulatory genes represented by the two-component signal transduction system have been analyzed. The development of inactivated vaccines, natural avirulent vaccines, gene-deletion attenuated vaccines, subunit vaccines, and glycoconjugate vaccines have greatly contributed to the prevention and control of the disease in the future. This article aims to summarize the research progress to provide directions for future research and the prevention of S. suis.

Development of inactivated vaccine against virus causing haemorrhagic fever with renal syndrome.

B-1 virus belonging to the hantavirus group was serially passaged in the brains of newborn mice. Inactivated vaccine was prepared from the brains after inactivation with formalin and then purification by ultracentrifugation. The antigenic potency of this vaccine in vitro was determined by antibody-bound enzyme-linked immunosorbent assay (ELISA) and serial diluted vaccine bound to an aluminium hydroxide gel was inoculated into Balb/c mice to test immunogenicity. After two injections of this vaccine preparation, antibodies were detected in the mice by immunofluorescent, neutralizing and haemagglutination inhibition antibody tests. When mice immunized with this vaccine were challenged with B-1 virus and Hantaan virus (KHF-83-61BL strain), the virus titres in their lungs and spleens were significantly less than those in non-immunized mice. These results suggest that inactivated B-1 virus vaccine is effective against virus challenge by homotypic (B-1 virus) and heterotypic (Hantaan virus) viruses.