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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of a global pandemic that has led to more than 2.8 million deaths worldwide. Safe and effective vaccines are now available, including Moderna’s COVID-19 vaccine (mRNA-1273) that showed 94% efficacy in prevention of symptomatic COVID-19 disease in a phase 3 clinical study. mRNA-1273 encodes for a prefusion stabilized full length spike (S) protein of the Wuhan-Hu-1 isolate. However, the emergence of SARS-CoV-2 variants has led to concerns of viral escape from vaccine-induced immunity. Several emerging variants have shown decreased susceptibility to neutralization by vaccine induced immunity, most notably the B.1.351 variant, although the overall impact on vaccine efficacy remains to be determined. Here, we present the initial evaluation in mice of two updated COVID-19 mRNA vaccines designed to target emerging SARS-CoV-2 variants: (1) monovalent mRNA-1273.351 encodes for the S protein found in the B.1.351 lineage and (2) mRNA-1273.211 comprising a 1:1 mix of mRNA-1273 and mRNA-1273.351. Both vaccines were evaluated as a 2-dose primary series in mice; mRNA-1273.351 was also evaluated as a booster dose in animals previously vaccinated with 2-doses of mRNA-1273. The results demonstrated that a primary vaccination series of mRNA-1273.351 was effective at increasing neutralizing antibody titers against the B.1.351 lineage, while mRNA-1273.211 was most effective at providing broad cross-variant neutralization in mice. In addition, these results demonstrated a third dose of mRNA-1273.351 significantly increased both wild-type and B.1.351-specific neutralization titers. Both mRNA-1273.351 and mRNA-1273.211 are currently being evaluated in additional pre-clinical challenge models and in phase 1/2 clinical studies.

Background The fourth wave of COVID-19 in Osaka Prefecture, Japan, caused a medical crisis. Here, we aim to identify the risk factors for COVID-19 severity and compare patients between the first–third waves and the fourth wave. Methods We performed an observational retrospective study of COVID-19 cases at the National Hospital Organization Kinki-Chuo Chest Medical Center. Results We identified 404 patients (median age: 71.0 years [interquartile range: 56.0–80.0]), of whom 199 (49.1%) had mild disease, 142 (35.2%) had moderate disease, and 63 (15.6%) had severe disease. The overall mortality rate was 5.4% (22/404). Based on multivariate logistic regression analysis, cardiovascular disease, fever, dyspnea, and several inflammatory biomarkers were independent risk factors for moderate to severe disease. For every 1 mg/dL increase in C-reactive protein, 10 IU/L increase in lactate dehydrogenase, and 100 ng/mL increase in ferritin, the risk for moderate to severe disease increased by 18.3%, 12.9%, and 8.9%, respectively. Overall disease severity in the fourth wave was higher than in the first–third waves. However, there was no significant difference in mortality. Because of a shortage of beds, four of the 28 severe patients (14.3%) in the fourth wave could not be transferred to the advanced hospital. Conclusions Cardiovascular disease, fever, dyspnea, and several inflammatory biomarkers were risk factors for moderate to severe COVID-19 in our cohort. During the fourth wave, COVID-19 severity worsened, increasing the number of patients who could not be transferred to beds for severe cases, resulting in a medical crisis in Osaka.

Background: Over the last two decades, humanity has observed the extraordinary anomaly caused by novel, weird coronavirus strains, such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). As the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus has made its entry into the world, it has dramatically affected life in every domain by continuously producing new variants. The vaccine development is an ongoing process, although some vaccines got marketed. The big challenge is now whether the vaccine candidates can provide long-lasting protection or prevention against mutant variants. Methods: The information was gathered from various journals, electronic searches via Internet-based information such as PubMed, Google Scholar, Science Direct, online electronic journals, WHO landscape, world meters, WHO website, and News. Results: This review will present and discuss some coronavirus disease 19 (COVID-19) related aspects including: the pathophysiology, epidemiology, mutant variants vaccine candidates, vaccine efficacy, and management strategies. Due to the high death rate, continuous spread, an inadequate workforce, lack of required therapeutics, and incomplete understanding of the viral strain, it becomes crucial to build the knowledge of its biological characteristics and make available the rapid diagnostic and vital therapeutic machinery for the combat and management of an infection. Conclusion: The data summarizes current research on the COVID 19 infection and therapeutic interventions, which will direct future decision-making on the effort-worthy phases of the COVID 19 and the development of critical therapeutics. The only possible solution is the vaccine development targeting against all variant strains to halt its progress; the identified theoretical and practical knowledge can eliminate the gaps to improve a better understanding of the novel coronavirus structure and its design of a vaccine. In addition, to that the long-lasting protection is another challenging objective that need to be looked into.

Structured summary Background A characteristic feature of SARS-CoV-2 is its ability to transmit from pre- or asymptomatic patients, complicating the tracing of infection pathways and causing outbreaks. Despite several reports that whole genome sequencing (WGS) and haplotype networks are useful for epidemiologic analysis, little is known about their use in nosocomial infections. Aim We aimed to demonstrate the advantages of genetic epidemiology in identifying the link in nosocomial infection by comparing single nucleotide variations (SNVs) of isolates from patients associated with an outbreak in Showa University Hospital. Methods We used specimens from 32 patients in whom COVID-19 had been diagnosed using clinical reverse transcription-polymerase chain reaction tests. RNA of SARS-CoV-2 from specimens was reverse-transcribed and analysed using WGS. SNVs were extracted and used for lineage determination, phylogenetic tree analysis, and median-joining analysis. Findings The lineage of SARS-CoV-2 that was associated with outbreak in Showa University Hospital was B.1.1.214, which was consistent with that found in the Kanto metropolitan area during the same period. Consistent with canonical epidemiological observations, haplotype network analysis was successful for the classification of patients. Additionally, phylogenetic tree analysis revealed three independent introductions of the virus into the hospital during the outbreak. Further, median-joining analysis indicated that four patients were directly infected by any of the others in the same cluster. Conclusion Genetic epidemiology with WGS and haplotype networks is useful for tracing transmission and optimizing prevention strategies in nosocomial outbreaks.

Graphical abstract, Background The SARS-CoV-2 coronavirus epidemic is hastening the discovery of the most efficient vaccines. The development of cost-effective vaccines seems to be the only solution to terminate this Pandemic. However, the vaccines’ effectiveness has been questioned due to recurrent mutations in the SARS-CoV-2 genome. Most of the mutations are associated with the spike protein, a vital target for several marketed vaccines. Many Countries were highly affected by the 2nd wave of the SARS-CoV-2, like the UK, India, Brazil, France. Experts are also alarming the further COVID-19 wave with the emergence of Omicron, which is highly affecting the South African populations. This review encompasses the detailed description of all vaccine candidates and COVID-19 mutants that will add value to design further studies to combat the COVID-19 Pandemic. Methods The information was generated using various search engines like google scholar, PubMed, clinicaltrial.gov.in, WHO database, ScienceDirect, and news portals by using keywords SARS-CoV-2 Mutants, COVID-19 Vaccines, Efficacy of SARS-CoV-2 Vaccines, COVID-19 waves. Results This review has highlighted the evolution of SARS-CoV2 variants and the vaccine efficacy. Currently, various vaccine candidates are also undergoing several phases of development. Their efficacy still needs to check for newly emerged variants. We have focused on the evolution, multiple mutants, waves of the SARS-CoV-2, and different marketed vaccines undergoing various clinical trials and the design of the trials to determine vaccine efficacy. Conclusion Various mutants of SARS-CoV-2 arrived, mainly concerned with the spike protein, a key component to design the vaccine candidates. Various vaccines are undergoing clinical trial and show impressive results, but their efficacy still needs to be checked in different SARS-CoV-2 mutants. We discussed all mutants of SARS-CoV-2 and the vaccine's efficacy against them. The safety concern of these vaccines is also discussed. It is important to understand how coronavirus gets mutated to design better new vaccines, providing long-term protection and neutralizing broad mutant variants. A proper study approach also needs to be considered while designing the vaccine efficacy trials, which further improved the study outcomes. Taking preventive measures to protect from the virus is also equally important, like vaccine development.

Recently, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) resulted in Coronavirus Disease 2019 (COVID-19) outbreak. A new SARS-CoV-2 strain is expected to emerge in late 2020, including B.1.1.7. The high transmission rate of SARS-CoV-2 B.1.1.7 has raised public health concerns in several countries. Hence, in this study, we assessed the sequencing of SARS-COV2 to reveals the prevalence of the SARS-CoV-2 Alpha variant (B 1.1.7) in Egypt. We found that the viral transmission of the alpha variant is expanding. Moreover, based on hospitalizations and case fatality rates, there is a potential for increasing severity. There was no effect on susceptibility to Emergency Use Authorization monoclonal antibody treatments. However, there was minimal impact on neutralization by convalescent and post-vaccination sera. Samples have been clustered into the 20D sub clade for the majority of them. The eight samples shown in our study are considered the first recorded samples with the Alpha variant in Egypt. Therefore, The Egyptian government, represented by the Ministry of Health, must take all measures to examine the compatibility of the currently used vaccines with this new strain and the feasibility of the treatment protocol presently used with such strains developed in the Arab Republic of Egypt.

Objective To evaluate the SARS-CoV-2 anti-spike IgG antibodies production after the vaccination with BNT162b2 and the protection from symptomatic breakthrough infections in healthcare workers. Patients and methods This prospective observational study (RENAISSANCE) had as primary endpoint the evaluation of serologic response to BNT162b2 14-days after second dose. SARS-CoV-2 anti-spike IgG antibodies were evaluated with LIAISON® SARS-CoV-2 TrimericS IgG assay, able to detect presence of both binding and neutralizing antibodies for trimeric Spike glycoprotein. Subjects were recruited from February 1, 2021 to February 22, 2021. Occurrence of vaccine-breakthrough infections was assessed by RT-PCR on symptomatic/contact cases, up to June 6, 2021. Results Out of 2569 staff only were 4 non-responders (0.16%, 95%CI:0.04%-0.41%). All 4 non-responders were severely immunosuppressed and on treatment with mycophenolate mofetil/mycophenolic acid. At 14-days since 2° dose, the 67.5% of staff had anti-S IgG titers ≥2000 BAU/mL, 19.2% between 1500- 2000 BAU/ml, 9.8% between 1000-1500 BAU/ml, and 3.4% ≤1000 BAU/ml. Females had a higher probability of having higher titers than males (64.5% [1044/1618] vs. 58.3% [410/703]; p=0.005). This was confirmed after adjusting for age group (OR [95%CI]: 1.275 [1.062-1.531]; p=0.009). Four months after the end of vaccination program, only 13 subjects (0.26%) had experienced a breakthrough SARS-CoV-2 infection, including 1 non-responder. This subject was the only requiring hospitalization for severe COVID-19. Conclusion Vaccination campaign among healthcare workers at the ASST GOM Niguarda has resulted in a significative serologic response, and reduction of incident COVID-19 cases. Yet, the lack of protection should not be overlooked in immunocompromised subjects.

The best and safest way to control the coronavirus disease 2019 (COVID-19) pandemic is by using vaccination to generate widespread immunity. The urgent need to develop safe and effective COVID-19 vaccines was met with unprecedented speed and action from the global community. There are now 289 vaccines in the development pipeline. More remarkably, there are 20 publicly available vaccines, and more than 3.3 billion doses of COVID-19 vaccines have been administered across 180 countries. This is just the beginning of our fight against the pandemic. Even at the current vaccination rate, it could take years to vaccinate the world's population; many high-income countries are focusing on their needs, whereas the poorer nations are waiting for vaccines. There is still much that we do not understand about immunity to this new disease, and we will have to contend with the emerging variants. In this commentary, we describe the current status of COVID-19 vaccine development and provide insights into how the development and approvals happened so quickly. We discuss the clinical trial data that led to rapid emergency use authorization and the many challenges of global rollout. We also comment on some of the key unanswered questions and future directions for COVID-19 vaccine development and deployment.

The Delta variant of concern (VOC) of SARS-CoV-2 has become dominant worldwide. In this article, we report a cluster caused by B.1.617.2 harboring the additional mutation of concern (MOC) F490S. We observed that 5 fully vaccinated subjects aged between 47 and 84 years were infected with this variant. The immune escape mutation F490S, first identified in the Lambda VOI, appears to impair vaccine efficacy and is rapidly increasing in prevalence worldwide.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for causing the COVID-19 pandemic, can be detected in untreated wastewater. Wastewater surveillance of SARS-CoV-2 complements clinical data by offering earlier community-level detection, removing underlying factors such as access to healthcare, sampling asymptomatic patients, and reaching a greater population. Here, we compare 24-hour composite samples from the influents of two different wastewater treatment plants (WWTPs) in South Carolina, USA: Columbia and Rock Hill. The sampling intervals span the months of July 2020 and January 2021, which cover the first and second waves of elevated SARS-CoV-2 transmission and COVID-19 clinical cases in these regions. We identify four signature mutations in the surface glycoprotein (spike) gene that are associated with the following variants of interest or concern, VOI or VOC (listed in parenthesis): S477N (B.1.526, Iota), T478K (B.1.617.2, Delta), D614G (present in all VOC as of May 2021), and H655Y (P.1, Gamma). The N501Y mutation, which is associated with three variants of concern, was identified in samples from July 2020, but not detected in January 2021 samples. Comparison of mutations identified in viral sequence databases such as NCBI Virus and GISAID indicated that wastewater sampling detected mutations that were present in South Carolina, but not reflected in the clinical data deposited into databases., Graphical abstract Unlabelled Image

BackgroundNumerous countries imposed strict travel restrictions, contributing to the large socioeconomic burden during the COVID-19 pandemic. The long quarantines that apply to contacts of cases may be excessive for travel policy.MethodsWe developed an approach to evaluate imminent countrywide COVID-19 infections after 0–14-day quarantine and testing. We identified the minimum travel quarantine duration such that the infection rate within the destination country did not increase compared to a travel ban, defining this minimum quarantine as “sufficient.”FindingsWe present a generalised analytical framework and a specific case study of the epidemic situation on November 21, 2021, for application to 26 European countries. For most origin-destination country pairs, a three-day or shorter quarantine with RT-PCR or antigen testing on exit suffices. Adaptation to the European Union traffic-light risk stratification provided a simplified policy tool. Our analytical approach provides guidance for travel policy during all phases of pandemic diseases.InterpretationFor nearly half of origin-destination country pairs analysed, travel can be permitted in the absence of quarantine and testing. For the majority of pairs requiring controls, a short quarantine with testing could be as effective as a complete travel ban. The estimated travel quarantine durations are substantially shorter than those specified for traced contacts.FundingEasyJet (JPT and APG), the Elihu endowment (JPT), the Burnett and Stender families’ endowment (APG), the Notsew Orm Sands Foundation (JPT and APG), the National Institutes of Health (MCF), Canadian Institutes of Health Research (SMM) and Natural Sciences and Engineering Research Council of Canada EIDM-MfPH (SMM).Research in contextEvidence before this studyEvidence from early in the pandemic indicates that border closures at the epicentre slowed global dissemination of COVID-19. As community transmission became established in many nations, studies have suggested that the benefit of strict border closures in mitigating the transmission of disease from travellers diminished. Research for community settings has shown that testing later during quarantine, rather than upon entry into quarantine, can substantially shorten the duration of quarantine needed to reduce post-quarantine transmission. In particular for international air travellers, a 14-day quarantine can effectively be shortened to five or seven days. The number of infectious COVID-19 cases that escape from these quarantines depends on the prevalence of disease in the country the traveller originated as well as the travel volume into the country.Added value of this studyWe developed a framework to identify quarantine and testing strategies that enable travel from specific origins without increasing their infection rates per capita within destinations. No prior study has evaluated the appropriate duration of quarantine necessary to prevent any rise in infection rates per capita in the destination countries as a result of travel. By accounting for prevalence, daily incidence, vaccine coverage, immunity, age demographics, and travel flow between countries, we quantified the contribution of travel towards within-country the imminent infections in the destination country under different quarantine and testing strategies. For travel between 26 European countries, our results for the pandemic situation observed on November 21, 2021 demonstrate that there are often less burdensome quarantine and testing strategies that can serve as effective alternatives to strict border closure. Specifically, these estimated sufficient quarantine durations are especially dependent on COVID-19 prevalence and immunity within the two countries. We also found that asymmetry in the travel flow, just not the volume of travel flow, can also influence the estimated sufficient quarantine durations. Using data on variants of concern, including Omicron, we found that the adequacy of a border control strategy to limit variant spread depends strongly on the geographical distribution of the variant. While our results pertain to European countries, we also provide an interactive spreadsheet that can be used to determine appropriate quarantine durations between any two countries. Moreover, our framework can also be applied at any spatial or population scale within which movement restrictions could feasibly be implemented.Implications of all available evidenceTravel quarantine and testing strategies can effectively mitigate importation and onward transmission within a country. Identifying sufficient strategies can allow countries to permit travel to and from other countries, without risking a short-term increase in infection rates. As long as the community transmission is occurring, the long-term epidemic trend within the destination country is more apt to be determined by other disease control measures, e.g., contact tracing, vaccination, and non-pharmaceutical interventions. Together, travel quarantine and other related control measures can mitigate the risk of transmission between countries, limiting the threat of variants of concern.

Since late 2019, when SARS-CoV-2 was reported at Wuhan, several sequence analyses have been performed and SARS-CoV-2 genome sequences have been submitted in various databases. Moreover, the impact of these variants on infectivity and response to neutralizing antibodies has been assessed. In the present study, we retrieved a total number of 176 complete and high-quality S glycoprotein sequences of Iranian SARS-COV-2 in public database of the GISAID and GenBank from April 2020 up to May 2021. Then, we identified the number of variables, singleton and parsimony informative sites at both gene and protein levels and discussed the possible functional consequences of important mutations on the infectivity and response to neutralizing antibodies. Phylogenetic tree was constructed to represent the relationship between Iranian SARS-COV2 and variants of concern (VOC), variants of interest (VOI) and reference sequence. We found that the four current VOCs – Alpha, Beta, Gamma and Delta - are circulated in different regions in Iran. The Delta variant is notably more transmissible than other variants, and is expected to become a dominant variant. However, some of the Delta variants in Iran carry an additional mutation, namely E1202Q in the HR2 subdomain that might confer an advantage to viral/cell membrane fusion process. We also observed some more common mutations such as an N-terminal domain (NTD) deletion at position I210 and P863H in fusion peptide-heptad repeat 1 span region in Iranian SARS-COV-2. The reported mutations in the current project have practical significance in prediction of disease spread as well as design of vaccines and drugs.

COVID-19 has posed unforeseen circumstances and throttled major economies worldwide. India has witnessed two waves affecting around 31 million people representing 16% of the cases globally. To date, the epidemic waves have not been comprehensively investigated to understand pandemic progress in India. In the present study, we aim for a cross-sectional analysis since its first incidence up to 26th July 2021. We have performed the pan Indian evolutionary study using 20,086 high-quality complete genomes of SARS-CoV-2. Based on the number of cases reported and mutation rates, we could divide the Indian epidemic into seven different phases. First, three phases constituting the pre-first wave had a very less average mutation rate (

Emergence of new severe acute respiratory syndrome coronavirus 2 variants has raised concerns related to the effectiveness of vaccines and antibody therapeutics developed against the unmutated wildtype virus. Here, we examined the effect of the 12 most commonly occurring mutations in the receptor-binding domain of the spike protein on its expression, stability, activity, and antibody escape potential. Stability was measured using thermal denaturation, and the activity and antibody escape potential were measured using isothermal titration calorimetry in terms of binding to the human angiotensin-converting enzyme 2 and to neutralizing human antibody CC12.1, respectively. Our results show that mutants differ in their expression levels. Of the eight best-expressed mutants, two (N501Y and K417T/E484K/N501Y) showed stronger affinity to angiotensin-converting enzyme 2 compared with the wildtype, whereas four (Y453F, S477N, T478I, and S494P) had similar affinity and two (K417N and E484K) had weaker affinity than the wildtype. Compared with the wildtype, four mutants (K417N, Y453F, N501Y, and K417T/E484K/N501Y) had weaker affinity for the CC12.1 antibody, whereas two (S477N and S494P) had similar affinity, and two (T478I and E484K) had stronger affinity than the wildtype. Mutants also differ in their thermal stability, with the two least stable mutants showing reduced expression. Taken together, these results indicate that multiple factors contribute toward the natural selection of variants, and all these factors need to be considered to understand the evolution of the virus. In addition, since not all variants can escape a given neutralizing antibody, antibodies to treat new variants can be chosen based on the specific mutations in that variant.

Since December 2019, we have been in the battlefield with a new threat to the humanity known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we describe the four main methods used for diagnosis, screening and/or surveillance of SARS-CoV-2: Real-time reverse transcription polymerase chain reaction (RT-PCR); chest computed tomography (CT); and different complementary alternatives developed in order to obtain rapid results, antigen and antibody detection. All of them compare the highlighting advantages and disadvantages from an analytical point of view. The gold standard method in terms of sensitivity and specificity is the RT-PCR. The different modifications propose to make it more rapid and applicable at point of care (POC) are also presented and discussed. CT images are limited to central hospitals. However, being combined with RT-PCR is the most robust and accurate way to confirm COVID-19 infection. Antibody tests, although unable to provide reliable results on the status of the infection, are suitable for carrying out maximum screening of the population in order to know the immune capacity. More recently, antigen tests, less sensitive than RT-PCR, have been authorized to determine in a quicker way whether the patient is infected at the time of analysis and without the need of specific instruments.

BackgroundThe emergence of SARS-CoV-2 variants has caused an unexpected rebound globally. The World Health Organization has listed three variants (B.1.1.7, B.1.351, and P.1) as variants of concern. To understand the epidemiology and thereby plan appropriate safety measures, differential identification of the variants is indeed critical.ObjectivesAlthough whole-genome sequencing is the gold standard for variant identification, it is time-consuming and relatively expensive. Therefore, a rapid, easy, and cost-effective platform targeting multiple regions of the genome is required. Here, we assessed the usefulness of the Novaplex™ SARS-CoV-2 Variants I Assay kit in identifying mutations in the variants.Study designWe retrospectively examined 30 stored nasal swabs from COVID-19-positive patients tested between November 2020 and March 2021. RNA extracted from these swabs was subjected to the commercial kit and real-time reverse transcription-PCR was performed. To determine the genome sequences of SARS-CoV-2 in the collected samples and deduce the consensus sequences among the identified variants, genome sequencing libraries were prepared and mapped to the reference genome.ResultsFour of the tested samples were determined as variants. Of them, two harbored both H69/V70 deletion and N501Y substitution, whereas two harbored E484K substitution alone.ConclusionsThe variant with E484K substitution alone (“R.1”) has been now categorized as a variant of interest in Japan. Additionally, the kit-based assay was found to be feasible, convenient, and user-friendly in identifying the abovementioned mutations with a turnaround time of only 2 hours.