Navid Dashti; Forough Golsaz-Shirazi; Mahmood Jeddi-Tehrani; Amir-Hassan Zarnani; Mohammad Mehdi Amiri; Fazel Shokri
Abstract
Background: Since the outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several vaccine candidates have been developed within a short period of time. Although the potency of these vaccines was evaluated individually, their comparative potency was not comprehensively ...
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Background: Since the outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several vaccine candidates have been developed within a short period of time. Although the potency of these vaccines was evaluated individually, their comparative potency was not comprehensively evaluated.Objective: To compare the immunogenicity and neutralization efficacy of four approved COVID-19 vaccines in Iran, including: PastoCovac Plus, Sinopharm, SpikoGen, and Noora in BALB/c mice.Methods: Different groups of female BALB/c mice were vaccinated with three doses of each vaccine. The serum levels of antibodies against the viral receptor binding domain (anti-RBD) and spike (anti-spike) protein as well as the vaccine formulation (anti-vaccine) were evaluated using enzyme-linked immunosorbent assay (ELISA). The neutralization efficacy of these four vaccines was assessed through four neutralization assays: conventional virus neutralization test (cVNT), pseudotype virus neutralization test (pVNT), surrogate virus neutralization test (sVNT), and inhibition flow cytometry.Results: All four vaccines induced seroconversion in vaccinated animals. All vaccines successfully induced high levels of anti-vaccine antibody; however, PastoCovac Plus and Sinopharm vaccines induced significantly higher levels of anti-RBD antibody titer compared to Noora and SpikoGen. Moreover, the results of the antibody response were corroborated by the virus neutralization tests, which revealed very weak neutralization potency by Noora and SpikoGen in all tests.Conclusion: Our results indicate significant immunogenicity and neutralization efficacy induced by PastoCovac Plus and Sinopharm, but not by Noora and SpikoGen. This suggests the need for additional comparative assessment of the potency and efficacy of these four vaccines in vaccinated subjects.
Arslan Habib; Khalid Mahmood Anjum; Riffat Iqbal; Ghulam Jaffar; Zeeshan Ashraf; Malik ShahZaib Khalid; Muhammad Usman Taj; Syeda Wafa Zainab; Muhammad Umair; Muhammad Zohaib; Tabinda Khalid
Abstract
The most effective method to minimize the prevalence of infectious diseases is vaccination. Vaccines enhance immunity and provide protection against different kinds of infections. Subunit vaccines are safe and less toxic, but due to their lower immunogenicity, they need adjuvants to boost the immune ...
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The most effective method to minimize the prevalence of infectious diseases is vaccination. Vaccines enhance immunity and provide protection against different kinds of infections. Subunit vaccines are safe and less toxic, but due to their lower immunogenicity, they need adjuvants to boost the immune system. Adjuvants are small particles/molecules integrated into a vaccine to enhance the immunogenic feedback of antigens. They play a significant role to enhance the potency and efficiency of vaccines. There are several types of adjuvants with different mechanisms of action; therefore, improved knowledge of their immunogenicity will help develop a new generation of adjuvants. Many trials have been designed using different kinds of vaccine adjuvants to examine their safety and efficacy, but in practice, only a few have entered in animal and human clinical trials. However, for the development of safe and effective vaccines, it is important to have adequate knowledge of the side effects and toxicity of different adjuvants. The current review discussed the adjuvants which are available for producing modern vaccines as well as some new classes of adjuvants in clinical trials.
Enayat Anvari; Atefe Ghamar Talepoor; Mahsa Eshkevar Vakili; Narges Karimi; MohammadReza Ataollahi; Gelareh Najafi; Dieter Kabelitz; Iraj Ahmadi; Kurosh Kalantar
Abstract
Background: Vaccines are the most effective way to prevent Coronavirus 2 severe acute respiratory syndrome (SARS-CoV-2).Objectives: To compare the antibody response of healthy individuals vaccinated with either the AstraZeneca (ChAdOx1 nCoV-19) or the Sinopharm (BBIBP-CorV) vaccine, in those ...
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Background: Vaccines are the most effective way to prevent Coronavirus 2 severe acute respiratory syndrome (SARS-CoV-2).Objectives: To compare the antibody response of healthy individuals vaccinated with either the AstraZeneca (ChAdOx1 nCoV-19) or the Sinopharm (BBIBP-CorV) vaccine, in those who had no prior infection with SARS-CoV-2.Methods: Thirty seven participants were included, of which 17 were administered the AstraZeneca (ChAdOx1 nCoV-19) vaccine, while 20 were given the Sinopharm (BBIBP-CorV) vaccine. SARS-CoV-2 neutralizing antibody and anti-receptor-binding domain (RBD) IgG levels were checked 4 weeks after giving the first and the second dose of either vaccine using the enzyme-linked immunosorbent assay (ELISA) technique.Results: The AstraZeneca (ChAdOx1 nCoV-19) vaccine exhibited a higher levels of anti-(RBD) IgG compared with the Sinopharm (BBIBP-CorV) in both the first (14.51 μg/ml vs. 1.160 μg/ml) and the second (46.68 μg/ml vs. 11.43 μg/ml) doses. About neutralizing Abs, the titer of the antibody was higher in the AstraZeneca (ChAdOx1 nCoV-19) recipients than in the Sinopharm (BBIBP-CorV) subjects after the first (7.77 μg/ml vs. 1.79 μg/ml, p < 0.0001) and the second dose (10. 36 μg/ml vs. 4.88 μg/ml, p < 0.0001).Conclusions: Recipients vaccinated with two doses of the AstraZeneca (ChAdOx1 nCoV-19) had superior quantitative antibody levels than Sinopharm (BBIBP-CorV)-vaccinated subjects. These data suggest that a booster dose may be needed for the Sinopharm (BBIBP-CorV) recipients, to control the COVID-19 pandemic.
Hossein Forghani; Mahin Jamshidi Makiani; Hossein Zarei Jaliani; Seyed Mohsen Zahraei; Seyedeh Mahdieh Namayandeh; Parisa Khani
Abstract
Background: Currently evidence indicates the resurgence of whooping cough despite high coverage of whole-cell (wP) and acellular (aP) pertussis vaccines. Objective: In this study, we investigated the cell-mediated immune response of a genetically inactivated protein containing the S1 subunit of pertussis ...
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Background: Currently evidence indicates the resurgence of whooping cough despite high coverage of whole-cell (wP) and acellular (aP) pertussis vaccines. Objective: In this study, we investigated the cell-mediated immune response of a genetically inactivated protein containing the S1 subunit of pertussis toxin (PTS1) without and with the Listeriolysin O (LLO-PTS1), developed by the researchers (the authors of this study), in comparison with current wP and aP vaccines in the mice model. Methods: Thirty-six female NMRI mice aged 8 to 12 weeks (25 ± 5 g) were divided into six groups including control (n=6), and five treated groups (n=6/each). Treated groups comprising recombinant PTS1, recombinant fusion LLO-PTS1, aP, wP, and sham (phosphate-buffered saline) were injected intraperitoneally whereas the control group did not receive anything. After 60 days, the serum levels of IFN-γ, IL-4, and IL-17 cytokines (as the T-helper 1, 2, and 17 responses, respectively) were evaluated by mouse ELISA Kit. Results: Our findings showed LLO-PTS1 significantly increased IL-17 and IL-4 cytokines compared with wP and aP vaccines (superiority). IFN-γ failed to significantly increase in the LLO-PTS1 group compared to others but it was non-inferior to standard vaccines (non-inferiority). Conclusion: Our alum free mono-component monovalent recombinant fusion protein (LLO-PTS1), registered as a patent in the www.iripo.ssaa.ir, could bear the capacity to stimulate the Th-1 response similar to wP and aP vaccines (non-inferiority) in the mice model. In addition, it showed better results in Th-17 and Th-2 response (superiority). This study can be regarded as a springboard for further probes in booster pertussis vaccine development.
Mohammad Hadi Fakoor; Parviz Owlia; Seyed Latif Mousavi gargari; Azar Sabokbar
Abstract
Background: Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. Objective: To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Methods: ...
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Background: Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. Objective: To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Methods: Recombinant protein vaccine harboring the PcrV was expressed in the E. coli BL-21 strain. Mice were immunized with the purified recombinant protein, and the antibody titer was measured in the sera obtained from the immunized mice. Immunized and control mice werechallenged by active and passive immunization. The microbial counts in the lung, skin, liver, spleen, and kidney were compared with the control mice. Results: Bioinformatics analysis indicated that the PcrV protein was conserved in 1552 clinical and environmental isolates. Also, the isoelectric point (pI), molecular weight, and Grand Average of Hydropathy (GRAVY) score were analyzed. Mice were injected with recombinant protein, and serum from immunized mice reacted strongly with recombinant antigen at a dilution of 1:64000. The survival rate of mice infected with 5xLD50 of the P. aeruginosa increased significantly up to 75% in the standard strains (PAO1 and PAK), and the number of bacteria, especially in the internal organs (kidney, spleen, and liver) significantly reduced compared to the mice immunized with placebo. Conclusions: Our results demonstrated that the PcrV protein could be an effective candidate vaccine for the generation of antibody response against P. aeruginosa infection.
Ahmad Mehravaran; Mahmoud Reza Jaafari; Seyed Amir Jalali; Ali Khamesipour; Mohsen Tafaghodi; Mansure Hojatizade; Azam Abbasi; Ali Badiee
Volume 12, Issue 4 , December 2015, , Pages 274-287
Abstract
Background: Cationic immune stimulating complexes (PLUSCOMs) are particulate antigen delivery systems. PLUSCOMs consist of cationic immunostimulatory complexes (ISCOMs) derivatives and are able to elicit in vivo T cell responses against an antigen. Objective: To evaluate the effects of PLUSCOMs containing ...
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Background: Cationic immune stimulating complexes (PLUSCOMs) are particulate antigen delivery systems. PLUSCOMs consist of cationic immunostimulatory complexes (ISCOMs) derivatives and are able to elicit in vivo T cell responses against an antigen. Objective: To evaluate the effects of PLUSCOMs containing Leishmaniamajor antigens (SLA) on the type of immune response generated in the murine model of leishmaniasis. Methods: PLUSCOMs consisting of 1, 2-dioleoyl-3- trimethylammonium-propane (DOTAP) were used as antigen delivery system/immunoadjuvants for soluble SLA. BALB/c mice were immunized subcutaneously, three times in 2-week intervals. Footpads swellings at the site of challenge and parasite loads were assessed as a measure of protection. The immune responses were also evaluated by determination of IgG subclasses and the level of IFN- γ and IL-4 in cultured splenocytes. Results: There was no significant difference (p<0.05) between the sizes of lesions in mice immunized with different formulations. Also, there was no significant difference in the number of parasites in the footpad or spleen of all groups compared with the control group. The highest level of IFN- γ secretion was observed in the splenocytes of mice immunized with PLUSCOM/SLA (p<0.001) and lower amounts of IL-4 was observed in PLUSCOM group (p<0.001) as compared to negative control. Conclusion: Our results indicated that SLA in different formulations generated an immune response with mixed Th1/Th2 response that was not protective enough despite the activation of CD4 + T cells with secreting IFN-γ in groups which received PLUSCOM with antigen.
