Resistance of children to Covid-19. How?

Is there a role for growth hormone replacement in adults to control acute and post-acute COVID-19?

The SARS-CoV-2 pandemic created a multitude of medical crossroads requiring real time adaptations of best practice covering preventative and interventional aspects of care. Among the many discoveries borne from efforts to address the myriad clinical presentations across multiple organ systems was a common impact on tissues with cells that express the ACE-2 receptor. The vast majority of acute infections began and often ended in the respiratory tract, but more recent evaluations have confirmed significant extrapulmonary manifestations including symptom clusters that extend beyond the acute phase of infection collectively referred to as "post-acute sequelae SARS-CoV-2 infection" (PASC) or more commonly as "long (-haul) COVID". Both acute SARS-CoV-2 infection and PASC are associated with gut microbiome dysbiosis and alterations in the gut-brain and HPA-axis in a subset of the infected. Mounting evidence suggests these extrapulmonary manifestations may ultimately lead to reduced growth hormone (GH) secretion as demonstrated following stimulation tests. Disrupted GH secretion could cause or exacerbate long lasting neuropsychological symptoms as seen in other similar manifesting conditions. Ongoing clinical research has shown promising improvement in PASC patients with fatigue and cognition complaints can be achieved via GH replacement therapy. GH stimulation testing should be considered in PASC workups and future research should delve deeper into the mechanistic effects of GH on acute COVID and PASC.

Spread of SARS-CoV-2 Infection in Adult Populations in Cameroon: A Repeated Cross-Sectional Study Among Blood Donors in the Cities of Yaoundé and Douala

Over a period of about 9 months, we conducted three serosurveys in the two major cities of Cameroon to determine the prevalence of SARS-COV-2 antibodies and to identify factors associated with seropositivity in each survey. We conducted three independent cross-sectional serosurveys of adult blood donors at the Central Hospital in Yaoundé (CHY), the Jamot Hospital in Yaoundé (JHY) and at the Laquintinie Hospital in Douala (LHD) who consented in writing to participate. Before blood sampling, a short questionnaire was administered to participants to collect their sociodemographic and clinical characteristics. We included a total of 743, 1202, and 1501 participants in the first (January 25-February 15, 2021), second (May 03-28, 2021), and third (November 29-December 31, 2021) surveys, respectively. The adjusted seroprevalence increased from 66.3% (95% CrI 61.1-71.3) in the first survey to 87.2% (95% CrI 84.0-90.0) in the second survey, and 98.4% (95% CrI 96.8-99.7) in the third survey. In the first survey, study site, participant occupation, and comorbid conditions were associated with SARS-CoV-2 seropositivity, whereas only study site remained associated in the second survey. None of the factors studied was significantly associated with seropositivity in the third survey. Together, the data suggest a rapid initial spread of SARS-CoV-2 in the study population, independent of the sociodemographic parameters assessed.

Profiles of Independent-Comorbidity Groups in Senior COVID-19 Patients Reveal Low Fatality Associated with Standard Care and Low-Dose Hydroxychloroquine over Antivirals

Introduction

The lack of feasible therapies and comorbidities aggravate the COVID-19 case-fatality rate (CFR). However, reports examining CFR associations with diabetes, concomitant cardiovascular diseases, chronic kidney disease, and chronic liver disease (CLD) are limited. More studies assessing hydroxychloroquine (Hcq) and antivirals are needed.

Purpose

To examine associations of COVID-19 CFR in comorbid patient groups each with single comorbidities and after treatment with Hcq, favipiravir, and dexamethasone (Dex), either alone or in combination versus standard care.

Methods

Using statistical analysis, we descriptively determined these associations among 750 COVID-19 patient groups during the last quarter of 2021.

Results

A diabetes comorbidity (40%, n=299) showed twice the fatality (CFR 14%) of the others (CFR 7%; P=0.001). Hypertension (Htn) was the second-commonest comorbidity (29.5%, n=221), with similar CFR to diabetes (15% and 7% for Htn and non-Htn, respectively), but with higher significance (P=0.0006167). Although only 4% (n=30) heart failure (HF) was reported, the CFR (40%) was much higher than in those without it (8%). A similar rate (4%) for chronic kidney disease was reported, with CFRs of 33% and 9% among those with and without it, respectively (P=0.00048). Ischemic heart disease was 11% (n=74), followed by chronic liver disease (0.4%) and history of smoking (1%); however, these were not significant due to the sample sizes. Treatment indicated standard care and Hcq alone or in combination were superior (CFR of 4% and 0.5%, respectively) compared to favipiravir (25%) or Dex (38.5%) independently or in combination (35.4%). Furthermore, Hcq performed well (CFR 9%) when combined with Dex (9%; P=4.28-²⁶).

Conclusion

The dominance of diabetes and other comorbidities with significant association with CFR implied existence of a common virulence mechanism. The superiority of low-dose Hcq and standard care over antivirals warrants further studies.

Intestinal Shedding of SARS-CoV-2 in Children: No Evidence for Infectious Potential

The clinical courses of COVID-19 in children are often mild and may remain undiagnosed, but prolonged intestinal virus shedding has been documented, thus potentially enabling fecal-oral transmission. However, the infectious potential of SARS-CoV-2 viruses excreted with feces has remained unclear. Here, we investigated 247 stool specimens from 213 pediatric patients to assess the prevalence of intestinal SARS-CoV-2 shedding in hospitalized children without or with COVID-19 and determined the infectious capacity of stool-borne viruses. Upon RT-qPCR screening, the infectivity of virus-positive samples was tested in cell culture using the Vero-E6 permissive cell line. SARS-CoV-2 RNA was detected by RT-qPCR in 32 (13%) stool specimens, but the analysis of virus-positive samples in cell culture revealed no cytopathic effects attributable to SARS-CoV-2-related cell damage. Our findings do not support the notion of potential fecal-oral SARS-CoV-2 spreading, thus questioning the role of hygienic measures designed to prevent this mode of viral transmission.

Mucosal COVID-19 vaccines: Risks, benefits and control of the pandemic

Based on mucosal immunization to promote both mucosal and systemic immune responses, next-generation coronavirus disease 2019 (COVID-19) vaccines would be administered intranasally or orally. The goal of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is to provide adequate immune protection and avoid severe disease and death. Mucosal vaccine candidates for COVID-19 including vector vaccines, recombinant subunit vaccines and live attenuated vaccines are under development. Furthermore, subunit protein vac-cines and virus-vectored vaccines have made substantial progress in preclinical and clinical settings, resulting in SARS-CoV-2 intranasal vaccines based on the previously successfully used nasal vaccines. Additional to their ability to trigger stable, protective immune responses at the sites of pathogenic infection, the development of ‘specific’ mucosal vaccines targeting coronavirus antigens could be an excellent option for preventing future pandemics. However, their efficacy and safety should be confirmed.

Oral Lesions Associated with COVID-19 and the Participation of the Buccal Cavity as a Key Player for Establishment of Immunity against SARS-CoV-2

BACKGROUND

Some oral lesions have been described in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); the possibility has been raised that the buccal lesions observed in patients with the coronavirus disease 2019 (COVID-19) are due to this virus and the patient's systemic condition. The aim of this review was to integrate the knowledge related to the oral lesions associated with COVID-19 and the participation of the buccal cavity in the establishment of immunity against SARS-CoV-2.

METHODS

A literature search on the manifestations of buccal lesions from the beginning of the pandemic until October 2021 was carried out by using the PubMed database. A total of 157 scientific articles were selected from the library, which included case reports and reports of lesions appearing in patients with COVID-19.

RESULTS

Oral lesions included erosions, ulcers, vesicles, pustules, plaques, depapillated tongue, and pigmentations, among others. The oral cavity is a conducive environment for the interaction of SARS-CoV-2 with the mucosal immune system and target cells; direct effects of the virus in this cavity worsen the antiviral inflammatory response of underlying oral disorders, immunodeficiencies, and autoimmunity primarily.

CONCLUSIONS

The oral cavity is an accessible and privileged environment for the interaction of SARS-CoV-2 with the mucosal immune system and target cells; the direct effects of the virus in this cavity worsen the antiviral inflammatory response of underlying oral disorders, in particular those related to immunodeficiencies and autoimmunity.

Intranasal COVID-19 vaccines: From bench to bed

Currently licensed COVID-19 vaccines are all designed for intramuscular (IM) immunization. However, vaccination today failed to prevent the virus infection through the upper respiratory tract, which is partially due to the absence of mucosal immunity activation. Despite the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the next generation of COVID-19 vaccine is in demand and intranasal (IN) vaccination method has been demonstrated to be potent in inducing both mucosal and systemic immune responses. Presently, although not licensed, various IN vaccines against SARS-CoV-2 are under intensive investigation, with 12 candidates reaching clinical trials at different phases. In this review, we give a detailed description about current status of IN COVID-19 vaccines, including virus-vectored vaccines, recombinant subunit vaccines and live attenuated vaccines. The ongoing clinical trials for IN vaccines are highlighted. Additionally, the underlying mechanisms of mucosal immunity and potential mucosal adjuvants and nasal delivery devices are also summarized.

SARS-CoV-2 infection in India bucks the trend: Trained innate immunity?

SARS-CoV-2, the causative agent of COVID-19 pandemic caught the world unawares by its sudden onset in early 2020. Memories of the 1918 Spanish Flu were rekindled raising extreme fear for the virus, but in essence, it was the host and not the virus, which was deciding the outcome of the infection. Age, gender, and preexisting conditions played critical roles in shaping COVID-19 outcome. People of lower socioeconomic strata were disproportionately affected in industrialized countries such as the United States. India, a developing country with more than 1.3 billion population, a large proportion of it being underprivileged and with substandard public health provider infrastructure, feared for the worst outcome given the sheer size and density of its population. Six months into the pandemic, a comparison of COVID-19 morbidity and mortality data between India, the United States, and several European countries, reveal interesting trends. While most developed countries show curves expected for a fast-spreading respiratory virus, India seems to have a slower trajectory. As a consequence, India may have gained on two fronts: the spread of the infection is unusually prolonged, thus leading to a curve that is "naturally flattened"; concomitantly the mortality rate, which is a reflection of the severity of the disease has been relatively low. I hypothesize that trained innate immunity, a new concept in immunology, may be the phenomenon behind this. Biocultural, socioecological, and socioeconomic determinants seem to be influencing the outcome of COVID-19 in different regions/countries of the world.

SARS-CoV-2 antibody seroprevalence and associated risk factors in an urban district in Cameroon

The extent of SARS-CoV-2 circulation in many African countries remains unclear, underlining the need for antibody sero-surveys to assess the cumulative attack rate. Here, we present the results of a cross-sectional sero-survey of a random sample of residents of a health district in Yaounde, Cameroon, conducted from October 14 to November 26, 2020. Among the 971 participants, the test-adjusted seroprevalence of anti-SARS-CoV-2 IgG antibodies was 29·2% (95% CI 24·3-34·1). This is about 322 times greater than the 0.09% nationwide attack rate implied by COVID-19 case counts at the time. Men, obese individuals and those living in large households were significantly more likely to be seropositive, and the majority (64·2% [58·7-69·4]) of seropositive individuals reported no symptoms. Despite the high seroprevalence, most of the population had not been infected with SARS-CoV-2, highlighting the importance of continued measures to control viral spread and quick vaccine deployment to protect the vulnerable.

Prevalence and Presentation of Paediatric Coronavirus Disease 2019 in Lagos, Nigeria

BACKGROUND

The objective of this study was to describe the prevalence and clinical features of coronavirus disease 2019 (COVID-19) among children (≤18 years) evaluated for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection at a testing centre in Lagos, Nigeria. Methodology. This was a retrospective study. Data on the sociodemographic, clinical characteristics and SARS-CoV-2 results of participants at a modified drive-through centre for COVID-19 test sample collection over four months were retrieved from the electronic medical records (EMR). Data obtained were analyzed using SPSS version 22.0.

RESULTS

A total of 307 children (≤18 years) were evaluated in this review. The prevalence of SARS-CoV-2 infection among the paediatric population was 16.3%. The median age (interquartile range (IQR)) was 9 (4-14) years. Common symptoms reported by the positive cases were fever (40.0%), cough (32.9%), sore throat (17.1%), and runny nose (15.7%). The majority of the positive cases had mild symptoms. Fever and sore throat were associated with the positive cases.

CONCLUSION

Fever and sore throat were associated with SARS-CoV-2 infection among our cohort which buttresses the need for a high level of suspicion and clinical acumen in the management of common febrile diseases in paediatric settings.

High Rates of SARS-CoV-2 Family Transmission in Children of Healthcare Workers During the First Pandemic Wave in Madrid, Spain: Serologic Study

BACKGROUND

Data on SARS-CoV-2 transmission among children living with healthcare workers (HCWs) are scarce.

METHODS

A cross-sectional study was performed at a tertiary Hospital in Madrid, including children of HCW who suffered from SARS-CoV-2 infection between March and May 2020. Children underwent enzyme-linked immunosorbent serological study for detecting SARS-CoV-2 antibodies: VIRCELL IgG assay.

RESULTS

One hundred thirteen children from 69 HCWs with confirmed SARS-CoV-2 infection were recruited: 47 children had positive IgG (41.6%). Children secondary attack rate was 43.7% (25% if both parents have had asymptomatic infection; 39.5% if one parent was symptomatic; and 47% when both parents had symptoms). Having a positive sibling was associated with a positive IgG result (odds ratio = 12.2; 95% confidence interval: 4.4-33.7, P < 0.001). Median age was higher in IgG positive children (P = 0.022). Children who referred anosmia presented higher IgG titles (P < 0.04).

CONCLUSIONS

We observed a very high SARS-CoV-2 transmission in children of HCW during the first pandemic wave, especially when both parents were symptomatic. Having a positive sibling was associated with seroconversion, supporting the important role of family clusters in the transmission of SARS-CoV-2.

The Influence of Immune Immaturity on Outcome After Virus Infections

Maturation of the adaptive immune response is typically thought to improve outcome to virus infections. However, long-standing observations of natural infections with old viruses such as Epstein-Barr virus and newer observations of emerging viruses such as severe acute respiratory syndrome coronavirus 2 responsible for COVID-19 suggest that immune immaturity may be beneficial for outcome. Mechanistic studies and studies of patients with inborn errors of immunity have revealed that immune dysregulation reflecting inappropriate antibody and T-cell responses plays a crucial role in causing bystander inflammation and more severe disease. Further evidence supports a role for innate immunity in normally regulating adaptive immune responses. Thus, changes in immune responses that normally occur with age may help explain an apparent protective role of immune immaturity during virus infections.

Potential immuno-nanomedicine strategies to fight COVID-19 like pulmonary infections

COVID-19, coronavirus disease 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a pandemic. At the time of writing this (October 14, 2020), more than 38.4 million people have become affected, and 1.0 million people have died across the world. The death rate is undoubtedly correlated with the cytokine storm and other pathological pulmonary characteristics, as a result of which the lungs cannot provide sufficient oxygen to the body's vital organs. While diversified drugs have been tested as a first line therapy, the complexity of fatal cases has not been reduced so far, and the world is looking for a treatment to combat the virus. However, to date, and despite such promise, we have received very limited information about the potential of nanomedicine to fight against COVID-19 or as an adjunct therapy in the treatment regimen. Over the past two decades, various therapeutic strategies, including direct-acting antiviral drugs, immunomodulators, a few non-specific drugs (simple to complex), have been explored to treat Acute Respiratory Distress Syndrome (ARDS), Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), influenza, and sometimes the common flu, thus, correlating and developing specific drugs centric to COVID-19 is possible. This review article focuses on the pulmonary pathology caused by SARS-CoV-2 and other viral pathogens, highlighting possible nanomedicine therapeutic strategies that should be further tested immediately.

Multisystem inflammatory syndrome in children related to COVID-19: a systematic review

An association between a novel pediatric hyperinflammatory condition and SARS-CoV-2 was recently published and termed pediatric inflammatory multisystem syndrome, temporally associated with SARS-CoV-2 (PIMS-TS) or multisystem inflammatory syndrome (in children) (MIS(-C)). We performed a systematic review and describe the epidemiological, clinical, and prognostic characteristics of 953 PIMS-TS/MIS(-C) cases in 68 records. Additionally, we studied the sensitivity of different case definitions that are currently applied. PIMS-TS/MIS(-C) presents at a median age of 8 years. Epidemiological enrichment for males (58.9%) and ethnic minorities (37.0% Black) is present. Apart from obesity (25.3%), comorbidities are rare. PIMS-TS/MIS(-C) is characterized by fever (99.4%), gastrointestinal (85.6%) and cardiocirculatory manifestations (79.3%), and increased inflammatory biomarkers. Nevertheless, 50.3% present respiratory symptoms as well. Over half of patients (56.3%) present with shock. The majority of the patients (73.3%) need intensive care treatment, including extracorporal membrane oxygenation (ECMO) in 3.8%. Despite severe disease, mortality is rather low (1.9%). Of the currently used case definitions, the WHO definition is preferred, as it is more precise, while encompassing most cases.Conclusion: PIMS-TS/MIS(-C) is a severe, heterogeneous disease with epidemiological enrichment for males, adolescents, and racial and ethnic minorities. However, mortality rate is low and short-term outcome favorable. Long-term follow-up of chronic complications and additional clinical research to elucidate the underlying pathogenesis is crucial. What is Known: • A novel pediatric inflammatory syndrome with multisystem involvement has been described in association with SARS-CoV-2. • To date, the scattered reporting of cases and use of different case definitions provides insufficient insight in the full clinical spectrum, epidemiological and immunological features, and prognosis. What is New: • This systematic review illustrates the heterogeneous spectrum of PIMS-TS/MIS(-C) and its epidemiological enrichment for males, adolescents, and racial and ethnic minorities. • Despite its severe presentation, overall short-term outcome is good. • The WHO MIS definition is preferred, as it is more precise, while encompassing most cases.

Why is COVID-19 less severe in children? A review of the proposed mechanisms underlying the age-related difference in severity of SARS-CoV-2 infections

In contrast to other respiratory viruses, children have less severe symptoms when infected with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we discuss proposed hypotheses for the age-related difference in severity of coronavirus disease 2019 (COVID-19).Factors proposed to explain the difference in severity of COVID-19 in children and adults include those that put adults at higher risk and those that protect children. The former include: (1) age-related increase in endothelial damage and changes in clotting function; (2) higher density, increased affinity and different distribution of angiotensin converting enzyme 2 receptors and transmembrane serine protease 2; (3) pre-existing coronavirus antibodies (including antibody-dependent enhancement) and T cells; (4) immunosenescence and inflammaging, including the effects of chronic cytomegalovirus infection; (5) a higher prevalence of comorbidities associated with severe COVID-19 and (6) lower levels of vitamin D. Factors that might protect children include: (1) differences in innate and adaptive immunity; (2) more frequent recurrent and concurrent infections; (3) pre-existing immunity to coronaviruses; (4) differences in microbiota; (5) higher levels of melatonin; (6) protective off-target effects of live vaccines and (7) lower intensity of exposure to SARS-CoV-2.

Mucosal Immunity in COVID-19: A Neglected but Critical Aspect of SARS-CoV-2 Infection

The mucosal immune system is the largest component of the entire immune system, having evolved to provide protection at the main sites of infectious threat: the mucosae. As SARS-CoV-2 initially infects the upper respiratory tract, its first interactions with the immune system must occur predominantly at the respiratory mucosal surfaces, during both inductive and effector phases of the response. However, almost all studies of the immune response in COVID-19 have focused exclusively on serum antibodies and systemic cell-mediated immunity including innate responses. This article proposes that there is a significant role for mucosal immunity and for secretory as well as circulating IgA antibodies in COVID-19, and that it is important to elucidate this in order to comprehend especially the asymptomatic and mild states of the infection, which appear to account for the majority of cases. Moreover, it is possible that mucosal immunity can be exploited for beneficial diagnostic, therapeutic, or prophylactic purposes.

Immune response in COVID-19: What do we currently know?

In 2002/2003 there was a pandemic denominate SARS (severe acute respiratory syndrome), caused by the SARS-CoV virus that belongs to the genera Betacoranavirus and the family Coronaviridae, generally responsible for influenza infections. In mid of 2019, a new disease by the coronavirus named by COVID-19 (SARS-CoV-2) emerged, both infections have flu symptoms, however they are infections that variable intensity, being medium to severe. In medium infections individuals have the virus and exhibit symptoms, however hospitalization is not necessary, in severe infections, individuals are hospitalized, have high pathology and in some cases progress to death. The virus is formed by simple positive RNA, enveloped, non-segmented, and presenting the largest genome of viruses constituting 32 Kb, consisting of envelope proteins, membrane, nucleocapsid and spike protein, which is essential in the interaction with the host cells. As for the origin of this virus, research has been intensified to determine this paradox and although the similarity with SARS-CoV, this virus did not has necessarily the same place of origin. As for the immune system, it is currently unknown how this new virus interacts. In this brief review, we demonstrate important considerations about the responses to this infection.

Pathophysiology of Cardiovascular Complications in COVID-19

Numerous recent studies have shown that patients with underlying cardiovascular disease (CVD) are at increased risk of more severe clinical course as well as mortality of COVID-19. Also, the available data suggests that COVID-19 is related to numerous de novo cardiovascular complications especially in the older population and those with pre-existing chronic cardiometabolic conditions. SARS-CoV-2 virus can cause acute cardiovascular injury, as well as increase the risk of chronic cardiovascular damage. As CVD seem to be the major comorbidity in critically unwell patients with COVID-19 and patients often die of cardiovascular complications, we review the literature and discuss the possible pathophysiology and molecular pathways driving these disease processes: cytokine release syndrome, RAAS system dysregulation, plaque destabilization and coagulation disorders with the aim to identify novel treatment targets. In addition, we review the pediatric population, the major cause of the cardiovascular complications is pediatric inflammatory multisystem syndrome that is believed to be associated with COVID-19 infection. Due to the increasingly recognized CVD damage in COVID-19, there is a need to establish clear clinical and follow-up protocols and to identify and treat possible comorbidities that may be risk factors for the development of cardiovascular complications.