Development of an Inactivated Vaccine against SARS CoV-2

The impact of previous SARS-CoV-2 infection on post-vaccine adverse events in individuals vaccinated with TURKOVAC or CoronaVac -inactivated COVID-19 vaccines

This study- a secondary analysis of data from a randomized, observer-blinded, non-inferiority study among volunteers between 18-55 y old in Türkiye- evaluated the impact of previous SARS-CoV-2 infection before the first dose of inactive TURKOVAC on post-vaccine local and systemic adverse events (AEs) comparing with CoronaVac. Of 1266 participants analyzed, 27.7% had a previous COVID-19 history. Local and systemic AEs were observed in 37.3% and 39% of the participants. The frequency of AEs was slightly higher in the first 30 minutes and 24 hours among participants with a COVID-19 history; none were severe. 1203 participants had a second dose vaccination, and 27.3% had a history of COVID-19. The frequencies of local and systemic AEs after the second dose were similar between those with and without a COVID-19 history. The TURKOVAC and CoronaVac showed similar frequencies of local and systemic AEs in the first 30 minutes after vaccination.

Genomic surveillance during the first two years of the COVID-19 pandemic - country experience and lessons learned from Türkiye

Background

Türkiye confirmed its first case of SARS-CoV-2 on March 11, 2020, coinciding with the declaration of the global COVID-19 pandemic. Subsequently, Türkiye swiftly increased testing capacity and implemented genomic sequencing in 2020. This paper describes Türkiye's journey of establishing genomic surveillance as a middle-income country with limited prior sequencing capacity and analyses sequencing data from the first two years of the pandemic. We highlight the achievements and challenges experienced and distill globally relevant lessons.

Methods

We tracked the evolution of the COVID-19 pandemic in Türkiye from December 2020 to February 2022 through a timeline and analysed epidemiological, vaccination, and testing data. To investigate the phylodynamic and phylogeographic aspects of SARS-CoV-2, we used Nextstrain to analyze 31,629 high-quality genomes sampled from seven regions nationwide.

Results

Türkiye's epidemiological curve, mirroring global trends, featured four distinct waves, each coinciding with the emergence and spread of variants of concern (VOCs). Utilizing locally manufactured kits to expand testing capacity and introducing variant-specific quantitative reverse transcription polymerase chain reaction (RT-qPCR) tests developed in partnership with a private company was a strategic advantage in Türkiye, given the scarcity and fragmented global supply chain early in the pandemic. Türkiye contributed more than 86,000 genomic sequences to global databases by February 2022, ensuring that Turkish data was reflected globally. The synergy of variant-specific RT-qPCR kits and genomic sequencing enabled cost-effective monitoring of VOCs. However, data analysis was constrained by a weak sequencing sampling strategy and fragmented data management systems, limiting the application of sequencing data to guide the public health response. Phylodynamic analysis indicated that Türkiye's geographical position as an international travel hub influenced both national and global transmission of each VOC despite travel restrictions.

Conclusion

This paper provides valuable insights into the testing and genomic surveillance systems adopted by Türkiye during the COVID-19 pandemic, proposing important lessons for countries developing national systems. The findings underscore the need for robust testing and sampling strategies, streamlined sample referral, and integrated data management with metadata linkage and data quality crucial for impactful epidemiological analysis. We recommend developing national genomic surveillance strategies to guide sustainable and integrated expansion of capacities built for COVID-19 and to optimize the effective utilization of sequencing data for public health action.

Recent development of oral vaccines (Review)

Oral immunization can elicit an effective immune response and immune tolerance to specific antigens. When compared with the traditional injection route, delivering antigens via the gastrointestinal mucosa offers superior immune effects and compliance, as well as simplicity and convenience, making it a more optimal route for immunization. At present, various oral vaccine delivery systems exist. Certain modified bacteria, such as Salmonella, Escherichia coli and particularly Lactobacillus, are considered promising carriers for oral vaccines. These carriers can significantly enhance immunization efficiency by actively replicating in the intestinal tract following oral administration. The present review provided a discussion of the main mechanisms of oral immunity and the research progress made in the field of oral vaccines. Additionally, it introduced the advantages and disadvantages of the currently more commonly administered injectable COVID-19 vaccines, alongside the latest advancements in this area. Furthermore, recent developments in oral vaccines are summarized, and their potential benefits and side effects are discussed.

Immunogenicity and protective efficacy of a co-formulated two-in-one inactivated whole virus particle COVID-19/influenza vaccine

Due to the synchronous circulation of seasonal influenza viruses and severe acute respiratory coronavirus 2 (SARS-CoV-2) which causes coronavirus disease 2019 (COVID-19), there is need for routine vaccination for both COVID-19 and influenza to reduce disease severity. Here, we prepared individual WPVs composed of formalin-inactivated SARS-CoV-2 WK 521 (Ancestral strain; Co WPV) or influenza virus [A/California/07/2009 (X-179A) (H1N1) pdm; Flu WPV] to produce a two-in-one Co/Flu WPV. Serum analysis from vaccinated mice revealed that a single dose of Co/Flu WPV induced antigen-specific neutralizing antibodies against both viruses, similar to those induced by either type of WPV alone. Following infection with either virus, mice vaccinated with Co/Flu WPV showed no weight loss, reduced pneumonia and viral titers in the lung, and lower gene expression of proinflammatory cytokines, as observed with individual WPV-vaccinated. Furthermore, a pentavalent vaccine (Co/qFlu WPV) comprising of Co WPV and quadrivalent influenza vaccine (qFlu WPV) was immunogenic and protected animals from severe COVID-19. These results suggest that a single dose of the two-in-one WPV provides efficient protection against SARS-CoV-2 and influenza virus infections with no evidence of vaccine interference in mice. We propose that concomitant vaccination with the two-in-one WPV can be useful for controlling both diseases.

Long-Term Immunogenicity and Safety of a Homologous Third Dose Booster Vaccination with TURKOVAC: Phase 2 Clinical Study Findings with 32-Week Post-Booster Follow-Up

Vaccine-induced immunity wanes over time and warrants booster doses. We investigated the long-term (32 weeks) immunogenicity and safety of a third, homologous, open-label booster dose of TURKOVAC, administered 12 weeks after completion of the primary series in a randomized, controlled, double-blind, phase 2 study. Forty-two participants included in the analysis were evaluated for neutralizing antibodies (NAbs) (with microneutralization (MNT50) and focus reduction (FRNT50) tests), SARS-CoV-2 S1 RBD (Spike S1 Receptor Binding Domain), and whole SARS-CoV-2 (with ELISA) IgGs on the day of booster injection and at weeks 1, 2, 4, 8, 16, 24, and 32 thereafter. Antibody titers increased significantly from week 1 and remained higher than the pre-booster titers until at least week 4 (week 8 for whole SARS-CoV-2) (p < 0.05 for all). Seroconversion (titers ≥ 4-fold compared with pre-immune status) persisted 16 weeks (MNT50: 6-fold; FRNT50: 5.4-fold) for NAbs and 32 weeks for S1 RBD (7.9-fold) and whole SARS-CoV-2 (9.4-fold) IgGs. Nine participants (20.9%) tested positive for SARS-CoV-2 RT-PCR between weeks 8 and 32 of booster vaccination; none of them were hospitalized or died. These findings suggest that boosting with TURKOVAC can provide effective protection against COVID-19 for at least 8 weeks and reduce the severity of the disease.

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.

Analysis of participant-reported adverse events following the first dose of inactivated SARS-Cov-2 vaccine (TURKOVAC™) through telephone survey in Türkiye

BACKGROUND/OBJECTIVE(S)/INTRODUCTION

TURKOVAC™ is a whole-virion inactivated COVID-19 vaccine, which was developed and recently granted emergency use authorization (conditional marketing authorization) in Türkiye. The objective of this study is to assess the spectrum and the distribution of adverse events reported following the administration of the first 150,000 doses as primary and booster vaccine doses in 22 state hospitals of 17 provinces in Türkiye.

PATIENTS/MATERIALS AND METHODS

In this cohort study, a verbal survey was conducted via telephone calls between 10 January and 17 January 2022, utilizing a structured questionnaire algorithm on a sample group of 20,000 persons on the third- and seventh-days following vaccination. The algorithm consisted of two parts focusing on both systemic and local adverse effects. Other adverse events reported by the participants were also recorded. 6023 people and 5345 people agreed to participate in the telephone survey on the 3rd- and 7th- days of having received the first dose of the vaccine, respectively.

RESULTS

Thirty-six-point-six percent of the participants on the 3rd day and 22.5% of the participants on the 7th day reported any adverse event following the first dose of the vaccine. On both follow-up days, the most commonly reported (29.7% for Day 3 and 13.1% for Day 7) adverse events were on the injection site. Among the local adverse events, the most frequently reported one was the pain on the injection site (27.9% for Day 3 and 12.4% for Day 7), induration (4.8% for Day 3 and 2.7% for Day 7) and swelling (3.5% for Day 3 and 2.0% for Day 7). Fatigue/weakness (9.6% for Day 3 and 8.3% for Day 7) and headache (7.9% for Day 3 and 8.0% for Day 7) were the most frequent systemic adverse events. Younger age, vaccine dose, and female sex were associated with having any adverse event and pain (on the injection site). Female sex was associated with more swelling (on the injection site), induration (on the injection site), fever, and a higher impact on daily living.

CONCLUSION(S)

In this study, we conducted a rapid assessment of adverse events following the first dose of the TURKOVAC vaccine. The vaccine appears to have a good safety profile in the first 7 days following vaccination. Younger age, vaccine dose, and female sex are associated with any adverse event and pain (on the injection site). These results present valuable information for the community and may contribute to increasing vaccine confidence.KEY MESSAGESAs a whole-virion inactivated SARS-CoV-2 vaccine, the TURKOVAC™ vaccine, which has a favorable safety profile, can be an alternative to other COVID-19 vaccines including mRNA and viral vector vaccines.

Evaluation of local and systemic side effects of Turkovac vaccine in adults

BACKGROUND

COVID-19 is a respiratory disease that caused a pandemic after reportedly emerging from Wuhan, China, in December 2019. Different types of COVID-19 vaccines such as viral vectors, mRNA, and inactivated vaccines have been produced since the beginning of the pandemic. Turkovac is an inactive COVID-19 vaccine developed and produced in Türkiye. We conducted our study to investigate the local and systemic side effects of the Turkovac vaccine.

METHODS

A cross-sectional survey-based study was conducted to collect data on the postvaccine side effects in people aged over 18 who were vaccinated with Turkovac, between March and June 2022, in the Malatya Turgut Özal University Research and Training Hospital. A 54 question, multiple-choice questionnaire was used to collect demographic data from the participants and identify the possible local and systemic side effects after Turkovac vaccine administration.

RESULTS

Of the 403 participants included in the study, 134 (33.3%) were female and 269 (66.7%) were male with a mean age of 47.7 ± 13.7. The most common local side effects observed after vaccination were pain at the injection site (22.8%) and local swelling and redness (0.5%). Systemic side effects included weakness or fatigue (4.2%), muscle or joint pain (2%), headache (1.7%), fever (1%), cough (0.25%), lymphadenopathy (0.25%), and urticaria (0.25%). Side effects were most commonly observed within the first 24 h. We found that for participants under 47 years of age, female sex, chronic diseases, and regular medication use were associated with the risk of suffering side effects.

DISCUSSION

Our study revealed that Turkovac is a generally well-tolerated vaccine and had no side effects. More studies are required to evaluate Turkovac's side effects in other populations.

Long-Term Results of Immunogenicity of Booster Vaccination against SARS-CoV-2 (Hybrid COV-RAPEL TR Study) in Turkiye: A Double-Blind, Randomized, Controlled, Multicenter Phase 2 Clinical Study

The immunogenicity of vaccines decreases over time, causing a need for booster doses. This study aimed to present the long-term (Day 84) immunogenicity results of the double-blind, randomized, controlled, phase II Hybrid COV-RAPEL TR Study (NCT04979949), in which the TURKOVAC or CoronaVac vaccines were used as a booster after the second dose of primary vaccination with CoronaVac. A total of 190 participants from the Hybrid COV-RAPEL TR Study, who had both Day 28 and Day 84 immunogenicity results, were included. The immunogenicity on Day 84, regarding the neutralizing antibody positivity (Wuhan and Delta variants) and anti-spike immunoglobulin (Ig) G (IgG) antibody positivity, was compared between TURKOVAC and CoronaVac vaccine arms according to sex and age groups. Overall, antibody positivity showed a slight decrease on Day 84 vs. Day 28, but was not different between TURKOVAC and CoronaVac arms either for sexes or for age groups. However, TURKOVAC produced better antibody response against the Delta variant than CoronaVac, while CoronaVac was superior over TURKOVAC regarding neutralizing antibody positivity in the 50-60 years age group, regardless of the variant. A single booster dose, after the completion of the primary vaccination, increases antibody positivity on Day 28 which persists until Day 84 with a slight decrease. However, an additional booster dose may be required thereafter, since the decrease in antibody titer may be faster over time.

Inactivated and Immunogenic SARS-CoV-2 for Safe Use in Immunoassays and as an Immunization Control for Non-Clinical Trials

Successful SARS-CoV-2 inactivation allows its safe use in Biosafety Level 2 facilities, and the use of the whole viral particle helps in the development of analytical methods and a more reliable immune response, contributing to the development and improvement of in vitro and in vivo assays. In order to obtain a functional product, we evaluated several inactivation protocols and observed that 0.03% beta-propiolactone for 24 h was the best condition tested, as it promoted SARS-CoV-2 inactivation above 99.99% and no cytopathic effect was visualized after five serial passages. Moreover, RT-qPCR and transmission electron microscopy revealed that RNA quantification and viral structure integrity were preserved. The antigenicity of inactivated SARS-CoV-2 was confirmed by ELISA using different Spike-neutralizing monoclonal antibodies. K18-hACE2 mice immunized with inactivated SARS-CoV-2, formulated in AddaS0₃^TM, presented high neutralizing antibody titers, no significant weight loss, and longer survival than controls from a lethal challenge, despite RNA detection in the oropharyngeal swab, lung, and brain. This work emphasizes the importance of using different techniques to confirm viral inactivation and avoid potentially disastrous contamination. We believe that an efficiently inactivated product can be used in several applications, including the development and improvement of molecular diagnostic kits, as an antigen for antibody production as well as a control for non-clinical trials.

Molecular Characterization and Selection of Indigenous SARS-CoV-2 Delta Variant for the Development of the First Inactivated SARS-CoV-2 Vaccine of Pakistan

Vaccines are one of the efficient means available so far for preventing and controlling the infection rate of COVID-19. Several researchers have focused on the whole virus’s (SARS-CoV-2) inactivated vaccines which are economically efficient to produce. In Pakistan, multiple variants of SARS-CoV-2 have been reported since the start of the pandemic in February 2020. Due to the continuous evolution of the virus and economic recessions, the present study was designed to develop an indigenous inactivated SARS-CoV-2 vaccine that might help not only to prevent the COVID-19 in Pakistan, it will also save the country’s economic resources. The SARS-CoV-2 were isolated and characterized using the Vero-E6 cell culture system. The seed selection was carried out using cross-neutralization assay and phylogenetic analysis. The selected isolate of SARS-CoV-2 (hCoV-19/Pakistan/UHSPK3-UVAS268/2021) was inactivated using beta-propiolactone followed by vaccine formulation using Alum adjuvant, keeping the S protein concentration as 5 μg/dose. The vaccine efficacy was evaluated by in vivo immunogenicity testing in laboratory animals and in in vitro microneutralization test. The phylogenetic analysis revealed that all the SARS-CoV-2 isolates reported from Pakistan nested into different clades, representing multiple introductions of the virus into Pakistan. The antisera raised against various isolates from different waves in Pakistan showed a varied level of neutralization titers. However, the antisera produced against a variant (hCoV-19/Pakistan/UHSPK3-UVAS268/2021; fourth wave) efficiently neutralized (1:64–1:512) all the tested SARS-CoV-2 isolates. The inactivated whole virus vaccine of SARS-CoV-2 was safe and it also elicited a protective immune response in rabbits and rhesus macaques on the 35th-day post-vaccination. The activity of neutralizing antibodies of vaccinated animals was found at 1:256–1:1024 at 35 days post-vaccination, indicating the effectiveness of the double-dose regime of the indigenous SARS-CoV-2 vaccine.

A comparative study of the COVID-19 vaccine efficacy among cancer patients: mRNA versus non-mRNA

BACKGROUND

Cancer patients have an increased risk of a severe COVID-19 infection with higher mortality rate. This study aimed to analyze the levels of anti-SARS-CoV-2 S-RBD IgG and NAB among cancer patients who were vaccinated with COVID-19 vaccines, either with BNT162b2, mRNA-1273, AZD1222/ChAdOx1nCoV-19, or Coronavac/BBIBP-CorV vaccines.

METHOD

A cross-sectional study was conducted among subjects with either solid or hematological cancers who had received two doses of either mRNA or non-mRNA vaccines within 6 months. The levels of anti-SARS-CoV-2 S-RBD IgG and NAb were analyzed using the Mindray Immunoassay Analyzer CL-900i. Statistical analysis was conducted using mean comparison and regression analysis.

RESULT

The mRNA-1273 vaccine had the highest median levels of S-RBD IgG and NAb, followed by BNT162b, ChAdOx1nCoV-19, and BBIBP-CorV/Coronavac. The levels of S-RBD IgG and NAb in subjects vaccinated with mRNA vaccines were significantly higher than those of non-mRNA vaccines when grouped based on their characteristics, including age, type of cancer, chemotherapy regimen, and comorbidity (p<0.05). Furthermore, the S-RBD IgG and NAb levels between the subjects vaccinated with non-mRNA vaccines and the subjects vaccinated with mRNA vaccines were significantly different (p<0.05). However, there was no significant difference between the same types of vaccines. This study demonstrated a very strong correlation between the level of S-RBD IgG and the level of NAb (R = 0.962; p<0.001). The level of anti-SARS-CoV-2 S-RBD IgG was consistently higher compared to the level of NAb.

CONCLUSIONS

Generally, mRNA vaccines produced significantly higher anti-SARS-CoV-2 S-RBD IgG and NAb levels than non-mRNA vaccines in cancer subjects.

Safety and immunogenicity of an inactivated whole virion SARS-CoV-2 vaccine, TURKOVAC, in healthy adults: Interim results from randomised, double-blind, placebo-controlled phase 1 and 2 trials

BACKGROUND

Development of safe and effective vaccine options is crucial to the success of fight against COVID-19 pandemic. Herein, we report interim safety and immunogenicity findings of the phase 1&2 trials of ERUCoV-VAC, an inactivated whole virion SARS-CoV-2 vaccine.

METHODS

Double-blind, randomised, single centre, phase 1 and 2 trials included SARS-CoV-2 seronegative healthy adults aged 18-55 years (18-64 in phase 2). All participants, except the first 4 in phase 1 who received ERUCoV-VAC 3 μg or 6 μg unblinded and monitored for 7 days for safety purposes, were assigned to receive two intramuscular doses of ERUCoV-VAC 3 μg or 6 μg (an inactivated vaccine containing alhydrogel as adjuvant) or placebo 21 days apart (28 days in phase 2) according to computer-generated randomisation schemes. Both trials are registered at ClinicalTrials.gov (phase 1, NCT04691947 and phase 2, NCT04824391).

RESULTS

Forty-four participants (3 μg [n:17], 6 μg [n:17], placebo [n:10]) in phase 1 and 250 (3 μg [n:100], 6 μg [n:100], placebo [n:50]) in phase 2 received ≥1 dose. In phase 1 trial, 25 adverse events AEs (80 % mild) occured in 15 participants (34.1 %) until day 43. There was no dose-response relationship noted in safety events in ERUCoV-VAC recipients (p = 0.4905). Pain at injection site was the most common AE (9/44;20.5 %). Both doses of ERUCoV-VAC 3 μg and 6 μg groups were comparable in inducing SARS-CoV-2 wild-type neutralising antibody (MNT50): GMTs (95 %CI) were 8.3 (6.4-10.3) vs. 8.6 (7.0-10.2) at day 43 (p = 0.7357) and 9.7 (6.0-13.4) vs. 10.8 (8.8-12.8) at day 60 (p = 0.8644), respectively. FRNT50 confirmed MNT50 results: SARS-CoV-2 wild-type neutralising antibody GMTs (95 %CI) were 8.4 (6.3-10.5) vs. 9.0 (7.2-10.8) at day 43 (p = 0.5393) and 11.0 (7.0-14.9) vs. 12.3 (10.3-14.5) at day 60 (p = 0.8578). Neutralising antibody seroconversion rates (95 %CI) were 86.7 % (59.5-98.3) vs 94.1 % (71.3-99.8) at day 43 (p = 0.8727) and 92.8 % (66.1-99.8) vs. 100 % (79.4-100.0) at day 60 (p = 0.8873), in ERUCoV-VAC 3 μg and 6 μg groups, respectively. In phase 2 trial, 268 AEs, (67.2 % moderate in severity) occured in 153 (61.2 %) participants. The most common local and systemic AEs were pain at injection site (23 events in 21 [8.4 %] subjects) and headache (56 events in 47 [18.8 %] subjects), respectively. Pain at injection site was the only AE with a significantly higher frequency in the ERUCoV-VAC groups than in the placebo arm in the phase 2 study (p = 0.0322). ERUCoV-VAC groups were comparable in frequency of AEs (p = 0.4587). ERUCoV-VAC 3 μg and 6 μg groups were comparable neutralising antibody (MNT₅₀): GMTs (95 %CI) were 30.0 (37.9-22.0) vs. 34.9 (47.6-22.1) at day 43 (p = 0.0666) and 34.2 (23.8-44.5) and 39.6 (22.7-58.0) at day 60, (p = 0.2166), respectively. FRNT50 confirmed MNT50 results: SARS-CoV-2 wildtype neutralising antibody GMTs were 28.9 (20.0-37.7) and 30.1 (18.5-41.6) at day 43 (p = 0.3366) and 34.2 (23.8-44.5) and 39.6 (22.7-58.0) at day 60 (p = 0.8777). Neutralising antibody seroconversion rates (95 %CI) were 95.7 % (91.4-99.8) vs. 98.9 % (96.9-100.0) at day 43 (p = 0.8710) and 96.6 % (92.8-100.0) vs 98.9 % (96.7-100.0) at day 60 (p = 0.9129) in ERUCoV-VAC 3 μg and 6 μg groups, respectively.

CONCLUSIONS

Two-dose regimens of ERUCoV-VAC 3 μg and 6 μg 28 days both had an acceptable safety and tolerability profile and elicited comparable neutralising antibody responses and seroconversion rates exceeding 95 % at day 43 and 60 after the first vaccination. Data availability Data will be made available on request.

Recent review of COVID-19 management: diagnosis, treatment and vaccination

The idiopathic Coronavirus disease 2019 (COVID-19) pandemic outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reached global proportions; the World Health Organization (WHO) declared it as a public health emergency during the month of January 30, 2020. The major causes of the rise of new variants of SARS-CoV-2 are genetic mutations and recombination. Some of the variants with high infection and transmission rates are termed as variants of concern (VOCs) like currently Omicron variants. Pregnant women, aged people, and immunosuppressed and compromised patients constitute the most susceptible human population to the SARS-CoV-2 infection, especially to the new evolving VOCs. To effectively manage the pathological condition of infection, the focus should be directed towards prevention and prophylactic approach. In this narrative review, we aimed to analyze the current scenario of COVID-19 management and discuss the treatment and prevention strategies. We also focused on the complications prevalent during the COVID-19 and post-COVID period and to discuss the novel approaches developed for mitigation of the global pandemic. We have also emphasized on the COVID-19 management approaches for the special population including children, pregnant women, aged groups, and immunocompromised patients. We conclude that the advancements in therapeutic and pharmacological domains have provided opportunities to develop and design novel diagnosis, treatment, and prevention strategies. New advanced techniques such as RT-LAMP, RT-qPCR, High-Resolution Computed Tomography, etc., efficiently diagnose patients with SARS-CoV-2 infection. In the case of treatment options, new drugs like paxlovid, combinations of β-lactum drugs and molnupiravir are found to be effective against even the new emerging variants. In addition, vaccination is an essential approach to prevent the infection or to reduce its severity. Vaccines for against COVID-19 from Comirnaty by Pfizer-BioNTech, SpikeVax by Moderna, and Vaxzevria by Oxford-AstraZeneca are approved and used widely. Similarly, numerous vaccines have been developed with different percentages of effectiveness against VOCs. New developments like nanotechnology and AI can be beneficial in providing an efficient and reliable solution for the suppression of SARS-CoV-2. Public health concerns can be efficiently treated by a unified scientific approach, public engagement, and better diagnosis.

Safety and immunogenicity of inactive vaccines as booster doses for COVID-19 in Türkiye: A randomized trial

Protective neutralizing antibody titers reduce in time after COVID-19 vaccinations, as in individuals who have had COVID-19. This study aimed to evaluate the safety and immunogenicity of CoronaVac and TURKOVAC vaccines used as a booster dose after CoronaVac primary vaccination. This double-blind, randomized, controlled, phase II, multicenter study included healthy male and female adults (18-60 years) who were vaccinated with two doses of CoronaVac vaccine and did not exceed the duration of at least 90 days and a maximum of 270 days from the second dose of vaccination. Among 236 eligible volunteers, 222 were recruited for randomization between July 12, 2021 and September 10, 2021; 108 and 114 were randomized to the TURKOVAC and CoronaVac arms, respectively. The primary endpoint was adverse events (AEs) (ClinicalTrials.gov; Identifier: NCT04979949). On day 28, at the neutralizing antibody threshold of 1/6, the positivity rate reached 100% from 46.2% to 98.2% from 52.6% in the TURKOVAC and CoronaVac arms, respectively, against the Wuhan variant and the positivity rate reached 80.6% from 8.7% in the TURKOVAC arm vs. 71.9% from 14.0% in the CoronaVac arm against the Delta variant. IgG spike antibody positivity rate increased from 57.3% to 98.1% and from 57.9% to 97.4% in the TURKOVAC and CoronaVac arms, respectively. The TURKOVAC and CoronaVac arms were comparable regarding the frequency of overall AEs. Both vaccines administered as booster yielded higher antibody titers with acceptable safety profiles.

Efficacy, Immunogenicity, and Safety of the Two-Dose Schedules of TURKOVAC versus CoronaVac in Healthy Subjects: A Randomized, Observer-Blinded, Non-Inferiority Phase III Trial

We present the interim results of the efficacy, immunogenicity, and safety of the two-dose schedules of TURKOVAC versus CoronaVac. This was a randomized, observer-blinded, non-inferiority trial (NCT04942405). Volunteers were 18-55 years old and randomized at a 1:1 ratio to receive either TURKOVAC or CoronaVac at Day 0 and Day 28, both of which are 3 μg/0.5 mL of inactivated severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) adsorbed to aluminum hydroxide. The primary efficacy outcome was the prevention of polymerase chain reaction (PCR)-confirmed symptomatic coronavirus disease 2019 (COVID-19) at least 14 days after the second dose in the modified per-protocol (mPP) group. Safety analyses were performed in the modified intention-to-treat (mITT) group. Between 22 June 2021 and 7 January 2022, 1290 participants were randomized. The mITT group consisted of 915 participants, and the mPP group consisted of 732 participants. During a median follow-up of 90 (IQR 86-90) days, the relative risk reduction with TURKOVAC compared to CoronaVac was 41.03% (95% CI 12.95-60.06) for preventing PCR-confirmed symptomatic COVID-19. The incidences of adverse events (AEs) overall were 58.8% in TURKOVAC and 49.7% in CoronaVac arms (p = 0.006), with no fatalities or grade four AEs. TURKOVAC was non-inferior to CoronaVac in terms of efficacy and demonstrated a good safety and tolerability profile.

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.

Virological, Epidemiological Features and Prevention of SARS-CoV-2 Omicron (B.1.1.529) Variant: A Rewiev

The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant Omicron (B.1.1.529) has been a cause for serious concern worldwide due to its high rate of transmission and number of mutations. During genomic studies in South Africa and Botswana in November 2021, a new variant of SARS-CoV-2 was identified associated with a rapid resurgence of infections in Gauteng Province, South Africa. Omicron variant was identified as a type of concern by the World Health Organization after sequence uploads of the first genome. It was subsequently identified in 87 countries within three weeks. The Omicron variant is a very exceptional virus carrying more than 30 mutations in the spike glycoprotein that are predicted to affect antibody neutralization and spike function. Omicron is highly contagious and spreads faster than previous variants, but may cause less severe symptoms than previous variants. Omicron variant can evade the immune system. It can also evade the vaccine responses developed against COVID-19. Rapid and careful preventive steps, including vaccination, will always be a key for suppression of the Omicron variant. This review summarizes the highly mutated regions, core infectiousness, vaccine elimination, and antibody resistance of the Omicron variant of SARS-CoV-2.

Effect of inactivated COVID-19 vaccination on intrauterine insemination cycle success: A retrospective cohort study

Background

Vaccine hesitancy was found in couples seeking artificial reproductive technology (ART) services. As the main vaccine used in China, investigations into the influence of inactivated coronavirus disease 2019 (COVID-19) vaccines on human fertility is needed.

Methods

This retrospective cohort study included data on COVID-19 vaccination, clinical characteristics, and reproductive outcome of 1,000 intrauterine insemination (IUI) cycles in 653 couples from March 2021 to March 2022 in a single university hospital-based center for reproductive medicine. The IUI cycles were divided into two categories based on sperm source, including 725 cycles in 492 women undergoing artificial insemination with their husband's sperm (AIH) and 275 cycles in 161 women undergoing artificial insemination with donor sperm (AID). Women were then divided into two groups. The vaccine exposed group included women vaccinated prior to insemination and the unexposed group included women who were not vaccinated or vaccinated after insemination. Reproductive outcomes including ongoing pregnancy rate, clinical pregnancy rate, and miscarriage rate were assessed.

Results

Inactivated COVID-19 vaccinated women prior to intrauterine insemination in AIH cycles have comparable ongoing pregnancy rate (11.1 vs. 10.3%, P = 0.73), clinical pregnancy rate (12.5 vs. 11.3%, P = 0.60) as compared with unvaccinated counterparts. Similarly, there were no significant differences in ongoing pregnancy rate (20.9 vs. 28.1%, P = 0.17), clinical pregnancy rate (21.7 vs. 28.8%, P = 0.19) between vaccine exposed and unexposed groups in AID cycles. Multivariable logistic regression analyses showed that inactivated COVID-19 vaccination status cannot independently influence the reproductive outcomes of AIH and AID cycles. Subgroup analysis of vaccine exposed cycles showed that doses of vaccination and Interval between the last dose of vaccination and insemination have no influence on the reproductive outcomes of AIH cycles.

Conclusions

No negative effects were found on female fertility in IUI cycles following exposure to the inactivated COVID-19 vaccine. These findings indirectly reflect the safety of inactivated COVID-19 vaccine toward reproductive health and help to mitigate vaccine hesitancy among people planning to conceive.

COVID-19 vaccination in patients receiving allergen immunotherapy (AIT) or biologicals-EAACI recommendations

Immune modulation is a key therapeutic approach for allergic diseases, asthma and autoimmunity. It can be achieved in an antigen-specific manner via allergen immunotherapy (AIT) or in an endotype-driven approach using biologicals that target the major pathways of the type 2 (T2) immune response: immunoglobulin (Ig)E, interleukin (IL)-5 and IL-4/IL-13 or non-type 2 response: anti-cytokine antibodies and B-cell depletion via anti-CD20. Coronavirus disease 2019 (COVID-19) vaccination provides an excellent opportunity to tackle the global pandemics and is currently being applied in an accelerated rhythm worldwide. The vaccine exerts its effects through immune modulation, induces and amplifies the response against the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Thus, as there may be a discernible interference between these treatment modalities, recommendations on how they should be applied in sequence are expected. The European Academy of Allergy and Clinical Immunology (EAACI) assembled an expert panel under its Research and Outreach Committee (ROC). This expert panel evaluated the evidence and have formulated recommendations on the administration of COVID-19 vaccine in patients with allergic diseases and asthma receiving AIT or biologicals. The panel also formulated recommendations for COVID-19 vaccine in association with biologicals targeting the type 1 or type 3 immune response. In formulating recommendations, the panel evaluated the mechanisms of COVID-19 infection, of COVID-19 vaccine, of AIT and of biologicals and considered the data published for other anti-infectious vaccines administered concurrently with AIT or biologicals.

An overview of current drugs and prophylactic vaccines for coronavirus disease 2019 (COVID-19)

Designing and producing an effective vaccine is the best possible way to reduce the burden and spread of a disease. During the coronavirus disease 2019 (COVID-19) pandemic, many large pharmaceutical and biotechnology companies invested a great deal of time and money in trying to control and combat the disease. In this regard, due to the urgent need, many vaccines are now available earlier than scheduled. Based on their manufacturing technology, the vaccines available for COVID-19 (severe acute respiratory syndrome coronavirus 2 (SAR-CoV2)) infection can be classified into four platforms: RNA vaccines, adenovirus vector vaccines, subunit (protein-based) vaccines, and inactivated virus vaccines. Moreover, various drugs have been deemed to negatively affect the progression of the infection via various actions. However, adaptive variants of the SARS-CoV-2 genome can alter the pathogenic potential of the virus and increase the difficulty of both drug and vaccine development. In this review, along with drugs used in COVID-19 treatment, currently authorized COVID-19 vaccines as well as variants of the virus are described and evaluated, considering all platforms.

An overview on inactivated and live-attenuated SARS-CoV-2 vaccines

After about 2 years since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first infections were detected in Wuhan city of China in December 2019, which was followed by a worldwide pandemic with a record of 5.41 million deaths. Due to urgent need for the development of a safe and effective vaccine for coronavirus disease 2019 (COVID-19), attempts for producing efficient vaccines are inexhaustibly continuing. According to a report by the World Health Organization (WHO) on COVID-19 vaccine tracker and landscape, there are 149 vaccine candidates all over the world. Inactivated SARS-CoV-2 vaccines as a conventional vaccine platform consist of whole virus particles grown in cell culture and inactivated by chemicals. Because of benefits such as antigenic similarity to real virion inducing humoral and cellular immune responses and ease for transport and storage, these vaccines, including the vaccines produced by Bharat Biotech, Sinopharm, and Sinovac, are in use at large scales. In this study, we have a review on inactivated SARS-CoV-2 vaccines that are passing their phase 3 and 4 clinical trials, population which was included in the trials, vaccine producers, the efficiency, adverse effects, and components of vaccines, and other vaccine features.

Replicating Viral Vector-Based Vaccines for COVID-19: Potential Avenue in Vaccination Arena

The "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)" is the third member of human coronavirus (CoV) that is held accountable for the current "coronavirus disease 2019 (COVID-19)" pandemic. In the past two decades, the world has witnessed the emergence of two other similar CoVs, namely SARS-CoV in 2002 and MERS-CoV in 2013. The extent of spread of these earlier versions was relatively low in comparison to SARS-CoV-2. Despite having numerous reports inclined towards the zoonotic origin of the virus, one cannot simply sideline the fact that no animal originated CoV is thus far identified that is considered similar to the initial edition of SARS-CoV-2; however, under-sampling of the diverse variety of coronaviruses remains a concern. Vaccines are proved to be an effective tool for bringing the end to such a devastating pandemic. Many vaccine platforms are explored for the same but in this review paper, we will discuss the potential of replicating viral vectors as vaccine carriers for SARS-CoV-2.