Ali Saffaei; Jafar Amani; Jafar Salimian; Gholamhossein Alishiri; Hassan Abolghasemi
Hineptch Daungsupawong; Viroj Wiwanitkit
Abstract
Dear EditorWe are writing to discuss the article titled “Comparative Immunogenicity and Neutralization Potency of Four Approved COVID-19 Vaccines in BALB/c Mice” (1). The study examined the immunogenicity and neutralization efficacy of four COVID-19 vaccines licensed in Iran in BALB/c mice. ...
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Dear EditorWe are writing to discuss the article titled “Comparative Immunogenicity and Neutralization Potency of Four Approved COVID-19 Vaccines in BALB/c Mice” (1). The study examined the immunogenicity and neutralization efficacy of four COVID-19 vaccines licensed in Iran in BALB/c mice. The vaccines included PastoCovac Plus, Sinopharm, SpikoGen, and Noora. The results showed that all four vaccines induced seroconversion in immunized animals and generated significant levels of anti-vaccine antibodies. Notably, PastoCovac Plus and Sinopharm produced higher levels of anti-RBD antibody titer compared to Noora and SpikoGen. One limitation of the study is the lack of detailed explanation for the differences in antibody responses and neutralization effectiveness among the vaccines. Future research could focus on identifying specific components of the vaccines that contribute to their immunogenicity and neutralizing efficacy. Understanding these mechanisms may lead to the development of more effective vaccines or vaccine combinations. Another limitation of the study is its exclusive focus on antibody responses and neutralization efficacy in BALB/c mice. To validate the findings, future studies could include human clinical trials or other animal models. Additionally, testing the vaccines against various viral variants could provide valuable information on their effectiveness against emerging strains.In conclusion, our study revealed significant sociodemographic disparities in COVID-19 vaccination rates, particularly in relation to booster shots. Individuals identifying as Black or Latinx, as well as those facing poverty or food insecurity, were less likely to receive multiple vaccine doses compared to their White and Asian counterparts. Additionally, vaccine uptake was lower among individuals without health insurance or regular healthcare providers. These findings highlight the importance of addressing and reducing disparities in vaccine access and compliance to ensure equitable protection against COVID-19. References:Dashti N, Golsaz-Shirazi F, Jeddi-Tehrani M, Zarnani AH, Amiri MM, Shokri F. Comparative Immunogenicity and Neutralization Potency of Four Approved COVID-19 Vaccines in BALB/c Mice. Iran J Immunol. 2024 Mar 4;21(1). doi: 10.22034/iji.2024.101060.2728. Online ahead of print. Author’s responseDear EditorWe appreciate the comments raised on our paper accepted for publication in IJI (doi: 10.22034/iji.2024.101060.2728). The commenters pointed out some limitations of our study regarding the clarification of the processes responsible for the variations in antibody response and virus neutralization potency of the vaccines included in this study. They suggested investigating the constituents of the vaccines to gain further insight into the components responsible for enhancement of vaccine efficacy. In fact, we have discussed all these issues in detail in the discussion of our article, taking into account the structure of the immunizing antigens, their expression profile in either eukaryotic or prokaryotic systems, the nature of the adjuvants, and the possibility of degradation or denaturation of the antigens, etc. The commenters also proposed validating the results through clinical trials in human as well as investigating the neutralization potency on different viral variants. Conducting a comparative assessment on human samples has also been highlighted in our paper. However, we did not recommend performing experiments on other virus variants, such as Omicron or its subtypes, because two of the vaccines (SpikoGen and Noora) failed to induce an appreciable virus neutralization response to the SARS-CoV-2 Delta variant. Thus, we could not expect any neutralization effect against highly mutated variants, such as Omicron.Finally, the conclusion paragraph provided by the commenters, regarding their data on the influence of sociodemographic and nutrition parameters on the immunogenicity of COVID-19 vaccines is not relevant to our study and cannot be interpreted in light of the findings reported in our paper.
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.
