Safety and potency of BIV1-CovIran inactivated vaccine candidate for SARS-CoV-2: A preclinical study

A review of the scientific literature on experimental toxicity studies of COVID-19 vaccines, with special attention to publications in toxicology journals

Since the reports of the first cases of COVID-19, in less than 5 years, a huge number of documents regarding that disease and the coronavirus (SARS-CoV-2), responsible for the infection, have been published. The tremendous number of scientific documents covers many topics on different issues directly related to COVID-19/SARS-CoV-2. The number of articles-including reviews-reporting adverse/side effects of the approved COVID-19 vaccines is considerable. A wide range of adverse/side effects have been reported in humans after COVID-19 vaccination: thrombotic events/thrombocytopenia, myocarditis/pericarditis, cutaneous reactions, immune-mediated effects, psychiatric adverse events, systemic lupus erythematosus, reproductive toxicity, and other miscellaneous adverse effects. In contrast, information on nonclinical studies conducted to assess the potential toxicity/adverse effects of the COVID-19 vaccines in laboratory animals, is comparatively very scarce. The present review was aimed at revising the scientific literature regarding the studies in laboratory animals on the toxic/adverse effects of COVID-19 vaccines. In addition, the investigations reported in those specific toxicology journals with the highest impact factors have been examined one by one. The results of the present review indicate that most nonclinical/experimental studies on the adverse/toxic effects of the COVID-19 vaccines and/or potential candidates showed-in general terms-a good safety profile. Only in some animal studies were certain adverse effects found. However, a rather surprising result has been the limited number of available (in the databases PubMed and Scopus) nonclinical studies performed by the companies that have been the largest manufacturers of mRNA vaccines in the world. It is assumed that these studies have been conducted. However, they have not been published in scientific journals, which does not allow the judgment of the international scientific community, including toxicologists.

Menstrual Cycle Disturbances after COVID-19 Vaccination: A Cross-Sectional Study

BACKGROUND

Following COVID-19 vaccination, some women suffered from menstrual cycle disturbances. This study aimed to investigate menstrual cycle disturbances after COVID-19 vaccination in women of reproductive age.

MATERIALS AND METHODS

This cross-sectional study was performed on 407 vaccinated women in the vaccination center of Imam Hossein Hospital (Tehran, Iran) between October 2021 and October 2022. They were interviewed based on a research-made checklist which consisted of two areas of questions about the baseline characteristics of participants and menstrual cycle characteristics to explore menstrual characteristics following COVID-19 vaccination.

RESULTS

The prevalence of menstrual disturbances was higher after the third dose (38.3%) compared with the second (27.9%) and first (17.7%) doses (P<0.001). After the first dose, a history of polycystic ovarian syndrome [PCOS, odds ratio (OR)=7.35, 95% confidential interval (CI)= (3.64-14.82), P<0.001] and menstrual disturbances with unknown etiology [OR=15.23, 95% CI=(6.30-36.80), P<0.001] could predict menstrual disturbances. After the second dose, a history of menstrual disturbances with unknown etiology [OR=3.83, 95% CI=(1.47-9.94), P=0.006] and menstrual disturbances after the first dose [OR=201.96, 95% CI= (40.99-994.90), P<0.001] were predictors of menstrual disturbances. After the third dose, a history of menstrual disturbances with unknown etiology [OR=3.09, 95% CI= (1.00-9.52), P=0.048], menstrual disturbances after the first [OR=9.82, 95% CI=(1.38-69.69), P=0.022] and second [OR=7.83, 95% CI=(1.46-41.92), P=0.016] doses could predict menstrual disturbances.

CONCLUSION

We detected that many women experienced various menstrual disturbances after vaccination against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Furthermore, a history of menstrual abnormalities (before COVID-19 vaccination and following the previous doses of these vaccines) was associated with developing menstrual disturbances.

COVID-19 Vaccines: Where Did We Stand at the End of 2023?

Vaccine development against SARS-CoV-2 has been highly successful in slowing down the COVID-19 pandemic. A wide spectrum of approaches including vaccines based on whole viruses, protein subunits and peptides, viral vectors, and nucleic acids has been developed in parallel. For all types of COVID-19 vaccines, good safety and efficacy have been obtained in both preclinical animal studies and in clinical trials in humans. Moreover, emergency use authorization has been granted for the major types of COVID-19 vaccines. Although high safety has been demonstrated, rare cases of severe adverse events have been detected after global mass vaccinations. Emerging SARS-CoV-2 variants possessing enhanced infectivity have affected vaccine protection efficacy requiring re-design and re-engineering of novel COVID-19 vaccine candidates. Furthermore, insight is given into preparedness against emerging SARS-CoV-2 variants.

Evaluation of Stability, Inactivation, and Disinfection Effectiveness of Mpox Virus

BACKGROUND

Mpox virus (MPXV) infections have increased in many countries since May 2022, increasing demand for diagnostic tests and research on the virus. To ensure personnel safety, appropriate and reliable measures are needed to disinfect and inactivate infectious samples; Methods: We evaluated the stability of infectious MPXV cultures stored at different temperatures and through freeze-thaw cycles. Heat physical treatment (56 °C, 70 °C, 95 °C), chemical treatment (beta-propiolactone (BPL)) and two commercialized disinfectants (Micro-Chem Plus (MCP) and ethanol) were tested against infectious MPXV cultures; Results: The results indicated that MPXV stability increases with lower temperatures. The MPXV titer was stable within three freeze-thaw cycles and only decreased by 1.04 log10 (lg) 50% cell culture infective dose (CCID50) per milliliter (12.44%) after twelve cycles. MPXV could be effectively inactivated at 56 °C for 40 min, 70 °C for 10 min, and 95 °C for 5 min. For BPL inactivation, a 1:1000 volume ratio (BPL:virus) could also effectively inactivate MPXV. A total of 2% or 5% MCP and 75% ethanol treated with MPXV for at least 1 min could reduce >4.25 lg; Conclusions: MPXV shows high stability to temperature and freeze-thaw. Heat and BPL treatments are effective for the inactivation of MPXV, while MCP and ethanol are effective for disinfection, which could help laboratory staff operate the MPXV under safer conditions and improve operational protocols.

Omicron-specific and bivalent omicron-containing vaccine candidates elicit potent virus neutralisation in the animal model

Omicron variant (B.1.1.529) is able to escape from naturally acquired and vaccine-induced immunity, which mandates updating the current COVID-19 vaccines. Here, we investigated and compared the neutralising antibody induction of the ancestral variant-based BIV1-CovIran vaccine, the Omicron variant-based BIV1-CovIran Plus vaccine, and the novel bivalent vaccine candidate, BBIV1-CovIran, against the Omicron and ancestral Wuhan variants on the rat model. After inactivating the viral particles, the viruses were purified and formulated. Bivalent vaccines were a composition of 2.5 µg (5 µg total) or 5 µg (10 µg total) doses of each ansectral-based and Omicron-based monovalent vaccine. Subsequently, the potency of the monovalent and bivalent vaccines was investigated using the virus neutralisation test (VNT). The group that received three doses of the Omicron-specific vaccine demonstrated neutralisation activity against the Omicron variant with a geometric mean titer of 337.8. However, three doses of the Wuhan variant-specific vaccine could neutralise the Omicron variant at a maximum of 1/32 serum dilution. The neutralisation activity of the Omicron-specific vaccine, when administered as the booster dose after two doses of the Wuhan variant-specific vaccine, was 100% against the Omicron variant and the Wuhan variant at 1/64 and 1/128 serum dilution, respectively. Three doses of 5 µg bivalent vaccine could effectively neutralise both variants at the minimum of 1/128 serum dilution. The 10 µg bivalent vaccine at three doses showed even higher neutralisation titers: the geometric mean of 388 (95% CI 242.2-621.7) against Omicron and 445.7 (95% CI 303.3-655.0) against Wuhan. It is shown that the candidate bivalent and Omicron-specific vaccines could elicit a potent immune response against both Wuhan-Hu-1 and Omicron BA.1 variants.

Lessons from COVID-19 Pandemic: A Successful Policy and Practice by Pasteur Institute of Iran

The present study aims to provide an insight to the comprehensive efforts of Pasteur Institute of Iran (PII) regarding COVID-19 management, research, achievements, and vaccine production, though there are many challenges. The relevant literature review was investigated through national and international database and also reports from the related research departments. Six strategies were taken by PII to manage the pandemic of COVID-19. While this pandemic has been hopefully controlled, SARS-CoV-2 could still be a potential threat. Therefore, COVID-19 data management and updated studies, as well as long-term safety and efficacy of the SARS-CoV-2 vaccines are still on the agenda.

Global Emergence of SARS-CoV2 Infection and Scientific Interventions to Contain its Spread

The global pandemic caused by COVID-19 posed a significant challenge to public health, necessitating rapid scientific interventions to tackle the spread of infection. The review discusses the key areas of research on COVID-19 including viral genomics, epidemiology, pathogenesis, diagnostics, and therapeutics. The genome sequencing of the virus facilitated the tracking of its evolution, transmission dynamics, and identification of variants. Epidemiological studies have provided insights into disease spread, risk factors, and the impact of public health infrastructure and social distancing measures. Investigations of the viral pathogenesis have elucidated the mechanisms underlying immune responses and severe manifestations including the long-term effects of COVID-19. Overall, the article provides an updated overview of the diagnostic methods developed for SARS-CoV-2 and discusses their strengths, limitations, and appropriate utilization in different clinical and public health settings. Furthermore, therapeutic approaches including antiviral drugs, immunomodulatory therapies, and repurposed medications have been investigated to alleviate disease severity and improve patient outcomes. Through a comprehensive analysis of these scientific efforts, the review provides an overview of the advancements made in understanding and tackling SARS-CoV-2, while underscoring the need for continued research to address the evolving challenges posed by this global health crisis.

Humoral immunogenicity assessment after receiving three types of SARS-CoV-2 vaccine

Several vaccines have been developed against SARS-CoV-2 and subsequently approved by national/international regulators. Detecting specific antibodies after vaccination enables us to evaluate the vaccine's effectiveness. We conducted a prospective longitudinal study among members of Tarbiat Modares University of Tehran, Iran, from 4 September 2021 until 29 December 2021. We aimed to compare the humoral immunogenicity of 3 vaccine types. Participants consisted of 462 adults. Anti-SARS-CoV-2 receptor-binding domain [RBD] IgG titer was compared in 3 groups, each vaccinated by available vaccines in Iran at the time: Oxford/AstraZeneca, COVIran Barekat, and Sinopharm. The median IgG titer was: 91.2, 105.6, 224.0 BAU/ml for Sinopharm, COVIran Barekat and Oxford/AstraZeneca respectively after the first dose; 195.2, 192.0, 337.6 BAU/ml after the second one. We also analyzed the frequency of antibody presence in each vaccine group, in the same order the results were 59.0%, 62.6% and 89.4% after the first dose and 92.1%,89.5% and 98.9% after the second. The comparison of results demonstrated that AstraZeneca vaccine is a superior candidate vaccine for COVID-19 vaccination out of the three. Our data also demonstrated statistically significant higher antibody titer among recipients with an infection history.

Efficacy and safety of an inactivated virus-particle vaccine for SARS-CoV-2, BIV1-CovIran: randomised, placebo controlled, double blind, multicentre, phase 3 clinical trial

OBJECTIVE

To report the efficacy, safety, and exploratory immunogenicity findings of two 5 µg doses of the BIV1-CovIran vaccine.

DESIGN

Randomised, placebo controlled, double blind, multicentre, phase 3 clinical trial.

SETTING

In six cities of Iran, including Bushehr, Isfahan, Karaj, Mashhad, Shiraz, and Tehran. The first vaccine or placebo injection of the first participant was on 16 May 2021 in Tehran. The last vaccine or placebo injection of the last participant occurred on 15 July 2021 in Isfahan.

PARTICIPANTS

20 000 participants aged 18-75 years were randomly assigned to the intervention or placebo groups with a ratio of 2:1.

INTERVENTION

5 µg vaccine or placebo with the interval of 28 days.

MAIN OUTCOME MEASURES

Vaccine efficacy for a 90 day follow-up period, safety and explanatory immunogenicity assessment, and variant detection during the trial.

RESULTS

20 000 participants were recruited and randomly assigned to receive BIV1-CovIran (n=13 335 (66.7%)) or placebo (n=6665 (33.3%)). Participants' mean age was 38.3 (standard deviation 11.2) years, and 6913 (34.6%) were female. Among vaccinated participants that had covid-19 reported during the follow-up (median 83 days), 758 (5.9%) had symptoms, 144 (1.1%) had severe infection, and seven (0.1%) were critical. Among participants who received placebo during the follow-up, 688 (10.7%) had symptoms, 221 (3.4%) had severe infection, and 19 (0.3%) were critical. Overall efficacy was 50.2% (95% confidence interval 44.7% to 55.0%) against symptomatic covid-19, 70.5% (63.7% to 76.1%) against severe disease, and 83.1% (61.2% to 93.5%) against critical cases. Two deaths were reported in the efficacy population in the placebo group, no deaths were from the intervention group. During follow-up, 41 922 adverse events were reported: 28 782 (68.7%) were adverse reactions, of which 19 363 (67.3%) were in the intervention group. Most adverse reactions were mild or moderate in severity (grade 1 or 2) and self-limiting. No serious adverse events were related to the injections. For variant investigation, of 119 participants positive for the SARS-CoV-2 variant, 106 (89.1%) were positive for the delta variant.

CONCLUSIONS

A two dose regimen of the BIV1-CovIran vaccine conferred efficacy of 50.2% against symptomatic covid-19, 70.5% against severe disease, and 83.1% against critical disease. Vaccination was well tolerated, with no safety concerns raised.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials, IRCT20201202049567N3.

FUNDING

Shifa-Pharmed Industrial Group.

COVID-19 Vaccines over Three Years after the Outbreak of the COVID-19 Epidemic

The outbreak of COVID-19 started in December 2019 and spread rapidly all over the world. It became clear that the development of an effective vaccine was the only way to stop the pandemic. It was the first time in the history of infectious diseases that the process of the development of a new vaccine was conducted on such a large scale and accelerated so rapidly. At the end of 2020, the first COVID-19 vaccines were approved for marketing. At the end of March 2023, over three years after the outbreak of the COVID-19 pandemic, 199 vaccines were in pre-clinical development and 183 in clinical development. The candidate vaccines in the clinical phase are based on the following platforms: protein subunit, DNA, RNA, non-replication viral vector, replicating viral vector, inactivated virus, virus-like particles, live attenuated virus, replicating viral vector combined with an antigen-presenting cell, non-replication viral vector combined with an antigen-presenting cell, and bacterial antigen-spore expression vector. Some of the new vaccine platforms have been approved for the first time for human application. This review presents COVID-19 vaccines currently available in the world, procedures for assurance of the quality and safety of the vaccines, the vaccinated population, as well as future perspectives for the new vaccine platforms in drug and therapy development for infectious and non-infectious diseases.

Characterization of stability, safety and immunogenicity of the mRNA lipid nanoparticle vaccine Iribovax® against COVID-19 in nonhuman primates

mRNA-lipid nanoparticle (mRNA-LNP) vaccines have proved their efficacy, versatility and unprecedented manufacturing speed during the COVID-19 pandemic. Here we report on the physicochemical properties, thermostability, immunogenicity, and protective efficacy of the nucleoside-modified mRNA-LNP vaccine candidate Iribovax® (also called SNEG2c). Injection of BALB/c mice, rabbits and nonhuman primates with two doses of SNEG2c induced production of high-titers of SARS-CoV-2 spike-specific and receptor-binding domain (RBD)-neutralizing antibodies in immunized animals. In addition to the strong humoral response, SNEG2c elicited substantial Th1-biased T-cell response. Sera from rhesus macaques immunized with a low dose of the vaccine showed robust spike-specific antibody titers 3-24× as high as those in convalescent sera from a panel of COVID-19 patients and 50% virus neutralization geometric mean titer of 1024 against SARS-CoV-2. Strikingly, immunization with SNEG2c completely cleared infectious SARS-CoV-2 from the upper and lower respiratory tracts of challenged macaques and protected them from viral-induced lung and trachea lesions. In contrast, the non-vaccinated macaques developed moderate to severe pulmonary pathology after the viral challenge. We present the results of repeat-dose and local tolerance toxicity and thermostability studies showing how the physicochemical properties of the mRNA-LNPs change over time and demonstrating that SNEG2 is safe, well tolerated and stable for long-term. These results support the planned human trials of SNEG2c.

Menstrual disturbances following COVID-19 vaccination: A probable puzzle about the role of endocrine and immune pathways

Menstruation is a monthly shedding of the uterine wall, presented by menstrual bleeding in women of reproductive age. Menstruation is regulated by fluctuation of estrogen and progesterone, as well as other endocrine and immune pathways. Many women experienced menstrual disturbances after vaccination against the novel coronavirus in the last two years. Vaccine-induced menstrual disturbances have led to discomfort and concern among reproductive-age women, such that some decided not to receive the subsequent doses of the vaccine. Although many vaccinated women report these menstrual disturbances, the mechanism is still poorly understood. This review article discusses the endocrine and immune changes following COVID-19 vaccination and the possible mechanisms of vaccine-related menstrual disturbances.

A Review of Inactivated COVID-19 Vaccine Development in China: Focusing on Safety and Efficacy in Special Populations

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been widespread globally, and vaccination is critical for preventing further spread or resurgence of the outbreak. Inactivated vaccines made from whole inactivated SARS-CoV-2 virus particles generated in Vero cells are currently the most widely used COVID-19 vaccines, with China being the largest producer of inactivated vaccines. As a result, the focus of this review is on inactivated vaccines, with a multidimensional analysis of the development process, platforms, safety, and efficacy in special populations. Overall, inactivated vaccines are a safe option, and we hope that the review will serve as a foundation for further development of COVID-19 vaccines, thus strengthening the defense against the pandemic caused by SARS-CoV-2.

Recombinant highly antigenic truncated fusion-based protein as a diagnostic antigen for anti-SARS-CoV-2 nucleocapsid antibody ELISA

Among the main structural protein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), nucleocapsid phosphoprotein (NP) exhibits high immunogenicity and is the most abundant viral protein produced and shed during infection. Detection of antibodies against NP may help assess the number of individuals exposed to SARS-COV-2 or vaccinated against it. Based on these findings and other structural and antigenic evaluations, we designed a recombinant truncated fusion NP-based protein for application in an immunoassay for detecting immunoglobulins in patients who have recovered from COVID-19. In this research, we aligned the NPs from SARS-CoV and SARS-CoV-2 and selected highly antigenic parts of the SARS-CoV-2 sequences based on in-silico studies. The protein was expressed under optimum conditions in the bacterial host BL21 and purified by nickel immobilized metal affinity chromatography. Moreover, the purity level was assessed by SDS-PAGE and Western blotting whereas the folding of the protein was evaluated by circular dichroism. Ultimately, we used the purified recombinant protein in ELISA development in which 42 samples from convalescent patients were compared with 20 samples of the past 2019 patients who had attended laboratories for various clinical check-ups. The sensitivity and specificity were determined as 71% and 90%, respectively, in the optimum cut-off point measured by the receiver operating characteristic curve.

A comparison between SARS-CoV-1 and SARS-CoV2: an update on current COVID-19 vaccines

Since the outbreak of the novel coronavirus disease 2019 (COVID-19) in Wuhan, China, many health care systems have been heavily engaged in treating and preventing the disease, and the year 2020 may be called as "historic COVID-19 vaccine breakthrough". Due to the COVID-19 pandemic, many companies have initiated investigations on developing an efficient and safe vaccine against the virus. From Moderna and Pfizer in the United States to PastocoVac in Pasteur Institute of Iran and the University of Oxford in the United Kingdom, different candidates have been introduced to the market. COVID-19 vaccine research has been facilitated based on genome and structural information, bioinformatics predictions, epitope mapping, and data obtained from the previous developments of severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1) and middle east respiratory syndrome coronavirus (MERS-CoV) vaccine candidates. SARS-CoV genome sequence is highly homologous to the one in COVID-19 and both viruses use the same receptor, angiotensin-converting enzyme 2 (ACE2). Moreover, the immune system responds to these viruses, partially in the same way. Considering the on-going COVID-19 pandemic and previous attempts to manufacture SARS-CoV vaccines, this paper is going to discuss clinical cases as well as vaccine challenges, including those related to infrastructures, transportation, possible adverse reactions, utilized delivery systems (e.g., nanotechnology and electroporation) and probable vaccine-induced mutations.

Variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Vaccine Effectiveness

The incidence and death toll due to SARS-CoV-2 infection varied time-to-time; and depended on several factors, including severity (viral load), immune status, age, gender, vaccination status, and presence of comorbidities. The RNA genome of SARS-CoV-2 has mutated and produced several variants, which were classified by the SARS-CoV-2 Interagency Group (SIG) into four major categories. The first category; “Variant Being Monitored (VBM)”, consists of Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), Epsilon (B.1.427, B.1.429), Eta (B.1.525), Iota (B.1.526), Kappa (B.1.617.1), Mu (B.1.621), and Zeta (P.2); the second category; “Variants of Concern” consists of Omicron (B.1.1.529). The third and fourth categories include “Variants of Interest (VOI)”, and “Variants of High Consequence (VOHC)”, respectively, and contain no variants classified currently under these categories. The surge in VBM and VOC poses a significant threat to public health globally as they exhibit altered virulence, transmissibility, diagnostic or therapeutic escape, and the ability to evade the host immune response. Studies have shown that certain mutations increase the infectivity and pathogenicity of the virus as demonstrated in the case of SARS-CoV-2, the Omicron variant. It is reported that the Omicron variant has >60 mutations with at least 30 mutations in the Spike protein (“S” protein) and 15 mutations in the receptor-binding domain (RBD), resulting in rapid attachment to target cells and immune evasion. The spread of VBM and VOCs has affected the actual protective efficacy of the first-generation vaccines (ChAdOx1, Ad26.COV2.S, NVX-CoV2373, BNT162b2). Currently, the data on the effectiveness of existing vaccines against newer variants of SARS-CoV-2 are very scanty; hence additional studies are immediately warranted. To this end, recent studies have initiated investigations to elucidate the structural features of crucial proteins of SARS-CoV-2 variants and their involvement in pathogenesis. In addition, intense research is in progress to develop better preventive and therapeutic strategies to halt the spread of COVID-19 caused by variants. This review summarizes the structure and life cycle of SARS-CoV-2, provides background information on several variants of SARS-CoV-2 and mutations associated with these variants, and reviews recent studies on the safety and efficacy of major vaccines/vaccine candidates approved against SARS-CoV-2, and its variants.

Towards novel nano-based vaccine platforms for SARS-CoV-2 and its variants of concern: Advances, challenges and limitations

Vaccination is the most effective tool available for fighting the spread of COVID-19. Recently, emerging variants of SARS-CoV-2 have led to growing concerns about increased transmissibility and decreased vaccine effectiveness. Currently, many vaccines are approved for emergency use and more are under development. This review highlights the ongoing advances in the design and development of different nano-based vaccine platforms. The challenges, limitations, and ethical consideration imposed by these nanocarriers are also discussed. Further, the effectiveness of the leading vaccine candidates against all SARS-CoV-2 variants of concern are highlighted. The review also focuses on the possibility of using an alternative non-invasive routes of vaccine administration using micro and nanotechnologies to enhance vaccination compliance and coverage.

Impact of SARS-CoV-2 Delta and Omicron variants on viral burden and cycle threshold in BNT162b2-vaccinated 12-18 years group

The SARS-CoV-2 pandemic continues to impact the medical, economic, social, and political areas worldwide. Although it has been claimed that children are the most responsible for the outbreaks as of September 2021, the statistics showed controversary. Although it showed no difference in viral load and Ct values between symptomatic children and symptomatic adults, or between asymptomatic children and asymptomatic adults, the molecular mechanism remains unclear. Here, we aimed to investigate the effects of different strains on infection by comparing viral load levels in pediatric patients aged 12–18 years, infected with different variants of SARS-CoV-2, and vaccinated with full-dose BNT162b2. In this retrospective study, a total of 200 patients aged 12–18 years, who were diagnosed with COVID-19 in our hospital, and vaccinated with full-dose BNT162b2, were analyzed according to their gender, age, viral load, and cycle threshold values. Viral RNA levels were evaluated using Ct values, a semi-quantitative proxy of viral load. While the findings did not show a significant difference between gender and age (P = 0.886 and P = 0.897, respectively), a significant difference was found between the Ct and viral load (P < 0.0001). In conclusion, SARS-CoV-2 viral load was higher in cases infected with SARS-CoV-2 Delta variant than SARS-CoV-2 Omicron variant (mean Ct = 23.05 ± 4.06, viral load = 7.8 × 105 copies/ml and mean Ct = 28.04 ± 3.02, viral load = 7.8 × 103 copies/ml, respectively). These findings indicated that the Delta variant had high viral load and our result could be one of the causes the Delta variant was more effective in the pandemic severity than the other variants in the October–December periods when the Delta variant was dominant in Northern Cyprus. During the same period, the severity of the disease was higher, with higher hospitalization and death rates.

Comparison of Physical and Biochemical Characterizations of SARS-CoV-2 Inactivated by Different Treatments

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused huge social and economic distress. Given its rapid spread and the lack of specific treatment options, SARS-CoV-2 needs to be inactivated according to strict biosafety measures during laboratory diagnostics and vaccine development. The inactivation method for SARS-CoV-2 affects research related to the natural virus and its immune activity as an antigen in vaccines. In this study, we used size exclusion chromatography, western blotting, ELISA, an electron microscope, dynamic light scattering, circular dichroism, and surface plasmon resonance to evaluate the effects of four different chemical inactivation methods on the physical and biochemical characterization of SARS-CoV-2. Formaldehyde and β-propiolactone (BPL) treatment can completely inactivate the virus and have no significant effects on the morphology of the virus. None of the four tested inactivation methods affected the secondary structure of the virus, including the α-helix, antiparallel β-sheet, parallel β-sheet, β-turn, and random coil. However, formaldehyde and long-term BPL treatment (48 h) resulted in decreased viral S protein content and increased viral particle aggregation, respectively. The BPL treatment for 24 h can completely inactivate SARS-CoV-2 with the maximum retention of the morphology, physical properties, and the biochemical properties of the potential antigens of the virus. In summary, we have established a characterization system for the comprehensive evaluation of virus inactivation technology, which has important guiding significance for the development of vaccines against SARS-CoV-2 variants and research on natural SARS-CoV-2.

Application of bioreactor technology for cell culture-based viral vaccine production: Present status and future prospects

Bioreactors are widely used in cell culture-based viral vaccine production, especially during the coronavirus disease 2019 (COVID-19) pandemic. In this context, the development and application of bioreactors can provide more efficient and cost-effective vaccine production to meet the global vaccine demand. The production of viral vaccines is inseparable from the development of upstream biological processes. In particular, exploration at the laboratory-scale is urgently required for further development. Therefore, it is necessary to evaluate the existing upstream biological processes, to enable the selection of pilot-scale conditions for academic and industrial scientists to maximize the yield and quality of vaccine development and production. Reviewing methods for optimizing the upstream process of virus vaccine production, this review discusses the bioreactor concepts, significant parameters and operational strategies related to large-scale amplification of virus. On this basis, a comprehensive analysis and evaluation of the various process optimization methods for the production of various viruses (SARS-CoV-2, Influenza virus, Tropical virus, Enterovirus, Rabies virus) in bioreactors is presented. Meanwhile, the types of viral vaccines are briefly introduced, and the established animal cell lines for vaccine production are described. In addition, it is emphasized that the co-development of bioreactor and computational biology is urgently needed to meet the challenges posed by the differences in upstream production scales between the laboratory and industry.

Analyzing Iranian opinions toward COVID-19 vaccination

OBJECTIVES

The aim of this study was to assess Iranian tweets in order to: (1) analyze Iranian views toward COVID-19-vaccination; (2) compare Iranian views toward homegrown and imported COVID-19-vaccines; (3) present an effective model for sentiment analysis tasks regarding critical issues such as COVID-19-vaccination.

DESIGN AND METHODS

Persian tweets mentioning homegrown and imported vaccines were retrieved between April 1 and and September 30, 2021. The sentiments of retrieved tweets were identified using a deep-learning sentiment-analysis model. A sarcasm detection model, based on a random forest classifier, was used to identify sarcastic tweets and thus minimize misclassification. Finally, Iranian views toward COVID-19 vaccination were investigated.

RESULTS

Subtle differences were found in the number of positive sentiments toward homegrown and imported vaccines, with the latter having dominant positive polarity. Negative sentiments regarding homegrown and imported vaccines increased in some months. No significant differences were observed between the percentages of overall positive and negative opinions toward vaccination.

CONCLUSION

It is worrisome that negative sentiments toward homegrown and imported vaccines increased in some months in Iran. Health organizations can focus on Twitter in order to promote positive messaging toward COVID-19 vaccination. Sarcasm detection enabled the identification of tweets that ironically stated positive sentiments toward vaccination, thus improving the accuracy of the sentiment analysis results. Our sentiment analysis-sarcasm detection model is a reliable tool for mitigating classification problems.

Assessment of BIV1-CovIran inactivated vaccine-elicited neutralizing antibody against the emerging SARS-CoV-2 variants of concern

OBJECTIVES

The BIV1-CovIran vaccine is highly effective against COVID-19. The neutralizing potency of all SARS-CoV-2 vaccines seems to be decreased against variants of concern. We assessed the sensitivity of the Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2) variants to neutralizing antibodies (NAbs) present in sera from individuals who had received the BIV1-CovIran candidate vaccine compared with an original Wuhan-related strain.

METHODS

The ability of vaccine serum to neutralize the variants was measured using the conventional virus neutralization test. The correlation of spike (S) protein antibody and anti-receptor binding domain with neutralizing activity was investigated.

RESULTS

The current study demonstrated that 29 of 32 (90.6%; 95% CI: 75.0-98.0) of the vaccinees developed NAbs against a Wuhan-related strain. It is noteworthy that 28 (87.50%) and 24 of 32 (75%) of the recipients were able to produce NAbs against Alpha, Beta, and Delta variants, respectively. Serum virus-neutralizing titres for different SARS-CoV-2 strains were weakly correlated with anti-receptor binding domain antibodies (Spearman r = 36-42, p < 0.05), but not S-binding antibodies (p > 0.05).

DISCUSSION

Although there was a reduction in neutralization titres against the Alpha, Beta, and Delta variants compared with the Wuhan strain, BIV1-CovIran still exhibited potent neutralizing activity against the SARS-CoV-2 variants of concern.

COVID-19 Vaccination in Italian Children: The Limits of Parental Rights

SARS-CoV-2 vaccination campaigns initially targeted the adult population. After the authorization of the main agencies, including the EMA (European Medicines Agency), the European Vaccination Plan now involves young people between the ages of 12-17 and 5-11. In assessing the child's "best interests", the refusal of vaccination by parents or guardians, in addition to the increased circulation of the virus, is responsible for the risk of social distancing. This reduction in social contacts, particularly during very sensitive ages such as adolescence, has been linked to the increased incidence of psychiatric illness, a significant reason for extending vaccination against SARS-CoV-2 in these younger children. One may consider that government should issue a law that allows the child to decide on the vaccination plan, even without the consent of the parents or guardians, without the need for a judge's ruling. The availability of the child should be the point of reference, according to the National Bioethics Committee, for consent to vaccination. The authors investigate the subject in depth in order to counteract vaccination hesitation, and promote the dissemination of correct scientific information, using every different possible communication tool, as well as social networks and schools.

Safety and immunogenicity of an inactivated virus particle vaccine for SARS-CoV-2, BIV1-CovIran: findings from double-blind, randomised, placebo-controlled, phase I and II clinical trials among healthy adults

OBJECTIVE

Assessing safety and immunogenicity of an inactivated whole virus particle vaccine.

DESIGN

Single-centre, double-blind, randomised, placebo-controlled, phase I (stage I: 18-50, stage II: 51-75 years), phase II (18-75 years) clinical trials.

SETTING

29 December 2020 to 22 April 2021.

PARTICIPANTS

Stage I-phase I: 56 participants; stage II-phase I: 32; phase II: 280.

INTERVENTION

During stage I, participants randomly (3:3:1) received 3 µg, 5 µg vaccine or placebo in a 14-day interval. Participants in stage II received two shots of 5 µg vaccine or placebo (3:1). In phase II, participants received 5 µg vaccine or placebo (4:1) in a 28-day interval.

PRIMARY AND SECONDARY OUTCOME MEASURES

Safety assessment and immunogenicity assessment via antibody response and conventional virus neutralisation test (cVNT).

RESULTS

All adverse events (AEs) were mild or moderate and transient in both phase I and phase II, and no AEs of special interest were reported. The seroconversion-rate of neutralising, antireceptor binding-domain (RBD) and anti-spike-glycoprotein (anti-S) antibodies 14-days after second dose of 5 µg vaccine in stage I was 70.8% (95% CI 48.9% to 87.4%), 87.5% (95% CI 67.6% to 97.3%), 91.7% (95% CI 73.0% to 99.0%). The antibody titres increased more among 5 µg than 3 µg. The corresponding rates for 3 µg vaccine were 45.8% (95% CI 25.6% to 67.2%), 54.2% (95% CI 32.8% to 74.5%) and 70.8% (95% CI 48.9% to 87.4%), respectively. In stage II, 100% (95% CI 84.6% to 100%), 86.4% (95% CI 65.1% to 97.1%) and 86.4% (95% CI 65.1% to 97.1%) of participants seroconverted for neutralising, anti-RBD and anti-S antibodies. In phase II, the seroconversion rate of neutralising-antibody was 82.8% (95% CI 77.0% to 87.6%), anti-RBD 77.0% (95% CI 70.7% to 82.6%) and anti-S 79.9% (95% CI 73.8% to 85.1%) on day 42. In the cVNT, the sera at 1/64 times dilution would neutralise SARS-CoV-2 among 91.7%, 77.3% and 82.5% of vaccinated participants in phase I-stage I, phase I-stage II and phase II clinical trials, respectively.

CONCLUSIONS

These results support further evaluation of this inactivated whole virus particle vaccine.

TRIAL REGISTRATION NUMBERS

IRCT20201202049567N1 and IRCT20201202049567N2 for phase I and IRCT20201202049567N3 for phase II.

Understanding on the possible routes for SARS CoV-2 invasion via ACE2 in the host linked with multiple organs damage

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), accountable for causing the coronavirus diseases 2019 (COVID-19), is already declared as a pandemic disease globally. Like previously reported SARS-CoV strain, the novel SARS-CoV-2 also initiates the viral pathogenesis via docking viral spike-protein with the membranal angiotensin-converting enzyme 2 (ACE2) - a receptor on variety of cells in the human body. Therefore, COVID-19 is broadly characterized as a disease that targets multiple organs, particularly causing acute complications via organ-specific pathogenesis accompanied by destruction of ACE2+ cells, including alveolus, cardiac microvasculature, endothelium, and glomerulus. Under such circumstances, the high expression of ACE2 in predisposing individuals associated with anomalous production of the renin-angiotensin system (RAS) may promote enhanced viral load in COVID-19, which comparatively triggers excessive apoptosis. Furthermore, multi-organ injuries were found linked to altered ACE2 expression and inequality between the ACE2/angiotensin-(1-7)/mitochondrial Ang system (MAS) and renin-angiotensin-system (RAS) in COVID-19 patients. However, the exact pathogenesis of multi-organ damage in COVID-19 is still obscure, but several perspectives have been postulated, involving altered ACE2 expression linked with direct/indirect damages by the virus-induced immune responses, such as cytokinin storm. Thus, insights into the invasion of a virus with respect to ACE2 expression site can be helpful to simulate or understand the possible complications in the targeted organ during viral infection. Hence, this review summarizes the multiple organs invasion by SARS CoV-2 linked with ACE2 expression and their consequences, which can be helpful in the management of the COVID-19 pathogenesis under life-threatening conditions.

Potency, toxicity and protection evaluation of PastoCoAd candidate vaccines: Novel preclinical mix and match rAd5 S, rAd5 RBD-N and SOBERANA dimeric-RBD protein

Despite substantial efforts, no effective treatment has been discovered for severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection. Therefore, vaccination to reach herd immunity is the ultimate solution to control the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to evaluate the potency, toxicity, and protection of candidate PastoCoAd vaccines as novel mix and match of recombinant adenovirus type 5 (rAd5) containing the full-length spike protein (rAd5-S), rAd5 containing the receptor-binding domain of S protein and nucleoprotein (rAd5 RBD-N), and SOBERANA dimeric RBD protein of SARS-CoV-2. Three vaccine candidates were developed against SARS-CoV-2 using adenoviral vectors, including the prime-boost (rAd5-S/rAd5 RBD-N), heterologous prime-boost (rAd5-S/ SOBERANA vaccine), and prime only (mixture of rAd5-S and rAd5 RBD-N). The rAd5-S and rAd5 RBD-N were produced with a Cytomegalovirus promoter and the human tissue plasminogen activator (tPA) leader sequence. The immunogenicity of vaccine candidates was also evaluated in mouse, rabbit, and hamster models and protection was evaluated in a hamster model. Following the injection of vaccine candidates, no significant toxicity was observed in the tissues of animal models. The immunogenicity studies of mice, rabbits, and hamsters showed that responses of total IgG antibodies were significantly higher with the prime-only and heterologous prime-boost vaccines as compared to the other groups (P < 0.009). Virus neutralizing antibodies were detected, and the level of cytokines related to humoral and cellular immunity increased significantly in all vaccinated models. A high cellular immunity response was found in the vaccinated groups compared to the controls. On the other hand, the vaccine challenge test showed that the virus titers significantly decreased in the pharynx and lung tissues of vaccinated hamsters compared to the control group. These successful findings suggest the safety and protection produced by the heterologous prime-boost vaccine (adenovector/ SOBERANA RBD), as well as a single dose of adenovector vaccine in animal models.

Case of possible encephalopathy following receiving the first dose of Iranian COVID-19Vaccine; COVIran Barakat

We report a case of possible encephalopathy after receiving the first dose of Iran's COVIran Barekat vaccine. The patient had no history of neurological or mental illness. Clinical examinations and radiology reports were performed and differential diagnoses were analyzed by the treatment team. Finally, the possible association between vaccination and encephalopathy was concluded.

SARS-CoV-2 and Coronavirus Disease Mitigation: Treatment Options, Vaccinations and Variants

COVID-19 is caused by a novel coronavirus (2019-nCoV), which was declared as a pandemic after it emerged in China 2019. A vast international effort has been conducted to prevent and treat COVID-19 due to its high transmissibility and severe morbidity and mortality rates, particularly in individuals with chronic co-morbidities. In addition, polymorphic variants increased the need for proper vaccination to overcome the infectivity of new variants that are emerging across the globe. Many treatment options have been proposed and more than 25 vaccines are in various stages of development; however, the infection peaks are oscillating periodically, which raises a significant question about the effectiveness of the prevention measures and the persistence of this pandemic disease. In this review, we are exploring the most recent knowledge and advances in the treatment and vaccination options as well as the new emerging variants of 2019-nCoV and the possible mitigation of one of the most aggressive pandemics in the last centuries.

A Perspective on the Roles of Adjuvants in Developing Highly Potent COVID-19 Vaccines

Several countries have made unremitting efforts to develop an optimal vaccine in the fight against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the increasing occurrence of SARS-CoV-2 variants, current vaccines show decreased neutralizing activities, especially towards the Omicron variant. In this context, adding appropriate adjuvants to COVID-19 vaccines can substantially reduce the number of required doses and improve efficacy or cross-neutralizing protection. We mainly focus on research progress and achievements associated with adjuvanted COVID-19 subunit and inactivated vaccines. We further compare the advantages and disadvantages of different adjuvant formulations in order to provide a scientific reference for designing an effective strategy for future vaccine development.

COVID-19 Vaccines Cost-Effectiveness Analysis: A Scenario for Iran

COVID-19 vaccines are supposed to be critical measure for ending the pandemic. Governments had to decide on the type of vaccine to provide for their population. In this decision-making process, cost-effectiveness analysis is considered a helpful tool. This study is a cost-effectiveness analysis utilized to calculate the incremental cost per averted disability-adjusted life year (DALY) by vaccination compared to no vaccination for different COVID-19 vaccines. The incremental cost-effectiveness ratio (ICER) for a vaccination with COVID-19 vaccines was estimated at 6.2 to 121.2 USD to avert one DALY and 566.8 to 10,957.7 USD per one death. The lowest and highest ICERs belong to Ad26.COV2.S and CoronaVac, respectively. Considering the scenario of Iran, vaccines that are recommended include ad26.cov2.s, chadox1-S, rAd26-S + rAd5-S, and BNT162b2 in the order of recommendation.