Complicating Infections Associated with Common Endemic Human Respiratory Coronaviruses

Rhinovirus infection and co-infection in children with severe acute respiratory infection during the COVID-19 pandemic period

Rhinovirus causes respiratory tract infections in children and is found in co-infections. The objective of this research was to study the clinical profile of rhinovirus infection and co-infection in children with severe acute respiratory infection (SARI) during the COVID-19 pandemic period. We included 606 children ranging in age from 0.1 to 144 months of age from March 2020 to December 2021, hospitalized in the Pediatric Intensive Care Unit (PICU). The samples were collected by secretion from the nasopharynx region. A total of 259 children were tested positive for viral infection, 153 (59.07%) of them had a single rhinovirus infection and, 56 (36.6%) were aged between 60.1 and 144 months. Nine types of co-infections were identified and were found coinfection with three or more viruses (22/104, 21.15%). Observing the seasonality, the number of cases was similar between 2020 (49.53%) and 2021 (51.47%). Patients with a single infection (86.88%) and coinfection (67.30%) were more likely to have coughed. Patients with co-infection required the use of O2 for longer than those with a single rhinovirus infection. Hemogram results obtained from individuals with a single infection had higher levels of urea when compared to patients with co-infection with and other respiratory viruses. Multiple correspondence analyses indicated different clinical symptoms and comorbidities in patients with co-infection compared to those with single infection. The results found that the rhinovirus was much prevalent virus during the pandemic period and was found in co-infection with other virus types, what is important to diagnostic for the correct treatment of patients.

COVID-19 among infants: key clinical features and remaining controversies

Infants aged <1 year represent a seemingly more susceptible pediatric subset for infections. Despite this, coronavirus disease 2019 (COVID-19) infection has not been proven as more serious in this age group (outside the very early neonatal period) than in others. Indeed, a considerable number of asymptomatic infections have been recorded, and the symptoms and morbidity associated with COVID- 19 differ minimally from those of other respiratory viral infections. Whether due to an abundance of caution or truly reduced susceptibility, infections in infants have not raised the same profile as those in other age groups. In addition to direct severe acute respiratory syndrome coronavirus 2 diagnostic tests, laboratory markers that differentiate COVID-19 from other viral infections lack specificity in infants. Gastrointestinal presentations are common, and the neurological complications of infection mirror those of other respiratory viral infections. There have been relatively few reports of infant deaths. Under appropriate precautions, breastfeeding in the context of maternal infections has been associated with tangible but infrequent complications. Vaccination during pregnancy provides protection against infection in infants, at least in the early months of life. Multi-inflammatory syndrome in children and multi-inflammatory syndrome in neonates are commonly cited as variants of COVID-19; however, their clinical definitions remain controversial. Similarly, reliable definitions of long COVID in the infant group are controversial. This narrative review examines the key clinical and laboratory features of COVID-19 in infants and identifies several areas of science awaiting further clarification.

Potential use of endemic human coronaviruses to stimulate immunity against pathogenic SARS-CoV-2 and its variants

While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes significant morbidity and mortality in humans, there is a wide range of disease outcomes following virus exposures. Some individuals are asymptomatic while others develop complications within a few days after infection that can lead to fatalities in a smaller portion of the population. In the present study, we have analyzed the factors that may influence the outcome of post-SARS-CoV-2 infection. One factor that may influence virus control is pre-existing immunity conferred by an individual's past exposures to endemic coronaviruses (eCOVIDs) which cause the common cold in humans and generally, most children are exposed to one of the four eCOVIDs before 2 years of age. Here, we have carried out protein sequence analyses to show the amino acid homologies between the four eCOVIDs (i.e. OC43, HKU1, 229E, and NL63) as well as examining the cross-reactive immune responses between SARS-CoV-2 and eCOVIDs by epidemiologic analyses. Our results show that the nations where continuous exposures to eCOVIDs are very high due to religious and traditional causes showed significantly lower cases and low mortality rates per 100,000. We hypothesize that in the areas of the globe where Muslims are in majority and due to religious practices are regularly exposed to eCOVIDs they show a significantly lower infection, as well as mortality rate, and that is due to pre-existing cross-immunity against SARS-CoV-2. This is due to cross-reactive antibodies and T-cells that recognize SARS-CoV-2 antigens. We also have reviewed the current literature that has also proposed that human infections with eCOVIDs impart protection against disease caused by subsequent exposure to SARS-CoV-2. We propose that a nasal spray vaccine consisting of selected genes of eCOVIDs would be beneficial against SARS-CoV-2 and other pathogenic coronaviruses.

Alterations in Patients' Clinical Outcomes and Respiratory Viral Pathogen Activity following the COVID-19 Pandemic

BACKGROUND

Before the COVID-19 pandemic, respiratory pathogens such as influenza, parainfluenza, and respiratory syncytial virus were the most commonly detected viruses among hospitalized patients with respiratory tract infections.

METHODS

This was a retrospective observational study of inpatients and outpatients who attended Jordan University Hospital and underwent Nasopharyngeal Aspiration (NPA) in the periods from December 2017 to December 2018 and from December 2021 to December 2022. The results of multiplex respiratory pathogen real-time PCR tests for nasopharyngeal swab specimens were extracted from the electronic-based molecular diagnostic laboratory record of JUH. We compared the prevalence of the detected viruses as well as the patients' characteristics and outcomes between the two periods.

RESULTS

The total number of included patients was 695. Our analysis showed that a higher percentage of patients with hypertension and diabetes presented before the pandemic compared to the same period after it (p-value < 0.001). The need for O2 devices, white blood cell counts, diastolic blood pressure, and the length of hospital stay were significantly higher among patients who presented before the pandemic (p-value < 0.050). Influenza H1N1 (8.70% vs. 4.03%), influenza B (1.67% vs. 0.25%), parainfluenza (1.00% vs. 0.00%), human metapneumovirus (5.35% vs. 0.76%), adenoviruses (6.35% vs. 3.02%), and coronaviruses (8.70% vs. 3.53%) were detected with higher frequency in the period before the pandemic (p-value = 0.011, 0.045, 0.045, 0.000, 0.035, 0.004). These results were similar in terms of changes in the detection rates of viruses after matching the number of tested patients between the periods before and after the pandemic.

CONCLUSIONS

We have demonstrated a reduction in the detection of several viruses, which might be due to the increase in public awareness toward infection protection measures after the COVID-19 pandemic.

Human Coronavirus OC43 as a Low-Risk Model to Study COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has had irreversible and devastating impacts on every aspect of human life. To better prepare for the next similar pandemic, a clear understanding of coronavirus biology is a prerequisite. Nevertheless, the high-risk nature of the causative agent of COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), requires the use of a cumbersome biosafety level-3 (BSL-3) confinement facility. To facilitate the development of preventive and therapeutic measures against SARS-CoV-2, one of the endemic strains of low-risk coronaviruses has gained attention as a useful research alternative: human coronavirus OC43 (HCoV-OC43). In this review, its history, classification, and clinical manifestations are first summarized. The characteristics of its viral genomes, genes, and evolution process are then further explained. In addition, the host factors necessary to support the life cycle of HCoV-OC43 and the innate, as well as adaptive, immunological responses to HCoV-OC43 infection are discussed. Finally, the development of in vitro and in vivo systems to study HCoV-OC43 and its application to the discovery of potential antivirals for COVID-19 by using HCoV-OC43 models are also presented. This review should serve as a concise guide for those who wish to use HCoV-OC43 to study coronaviruses in a low-risk research setting.

Prevalence of Common Human Coronaviruses (NL63, 229E, and OC43) in Adults before the COVID-19 Pandemic: a Single-Center Study from Turkey, 2015-2020

Common Human Coronaviruses (HCoVs), such as NL63, HKU1, 229E, and OC43, induce respiratory tract infections worldwide. Epidemiological studies of HCoVs are of paramount importance because the disease burden and trajectory (in years) have not been well addressed in adults. Here, we aimed to describe the burden of HCoVs in a hospital setting over five years before the coronavirus disease 2019 pandemic. This was a retrospective study of patients (>18 years) between January 1, 2015, and January 1, 2020, whose respiratory specimens were tested by multiplex real-time polymerase chain reaction. In total, 7,861 respiratory samples (4,540 patients) were included, 38% of which tested positive for any respiratory virus. Of these, 212 (12.2%) samples were positive for HCoVs, and their co-infection with other respiratory viruses was 30.6%. Rhinovirus (27.6%) was the most common co-infection among all three HCoVs. The overall prevalence of HCoVs tended to be the highest in the winter (40.9%). Patients aged ≥60 years had the highest prevalence of overall HCoVs (39.7%). Given the duration and large sample size, this study from Turkey is one of the largest to date among adults in the literature. These epidemiological data and molecular surveillance of HCoVs have important implications for the control and prevention of respiratory infections.

Disinfection and decontamination in the context of SARS-CoV-2-specific data

Given the high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as witnessed early in the coronavirus disease 2019 (COVID-19) pandemic, concerns arose with the existing methods for virus disinfection and decontamination. The need for SARS-CoV-2-specific data stimulated considerable research in this regard. Overall, SARS-CoV-2 is practically and equally susceptible to approaches for disinfection and decontamination that have been previously found for other human or animal coronaviruses. The latter have included techniques utilizing temperature modulation, pH extremes, irradiation, and chemical treatments. These physicochemical methods are a necessary adjunct to other prevention strategies, given the environmental and patient surface ubiquity of the virus. Classic studies of disinfection have also allowed for extrapolation to the eradication of the virus on human mucosal surfaces by some chemical means. Despite considerable laboratory study, practical field assessments are generally lacking and need to be encouraged to confirm the correlation of interventions with viral eradication and infection prevention. Transparency in the constitution and use of any method or chemical is also essential to furthering practical applications.

Respiratory viral infections other than SARS CoV-2 among the North Indian patients presenting with acute respiratory illness during the first COVID-19 wave

Acute respiratory infections due to viral or bacterial etiology can cause 60 deaths per one lakh population. Viral etiology is more common as compared to bacterial, but lack of definite diagnosis leads to increased usage of empirical antibiotics. During the first wave of the COVID-19 pandemic, there was a need to identify co-infections especially in severe acute respiratory illness (SARI) patients to identify it as one of the cofactors for increased severity of illness and to identify the causative agents in COVID-19 negative individuals. The SARS CoV-2 real time PCR was carried out using ICMR approved kits and the other respiratory viruses were detected using the multiplex commercially available real time  kit. A total of 186 patients presenting with either SARI (89.8%) or influenza like illness (10.2%) were included in the study. Out of these, 43 (23.1%) were positive for SARS CoV-2 RNA and 2 (4.6%) patients with SARI showed concomitant infection with either human rhinovirus or human respiratory syncytial virus . Out of 143 patients negative for SARS CoV-2, 35 (24.5%) were positive for one or more microbial infections and 28 (19.6%) infected with other respiratory viral infection most common being human rhinovirus. The results suggest that viral coinfections are significantly higher among COVID-19 negative individuals (24.5% vs 4.6%) presenting with respiratory illness as compared to COVID-19 positive individuals possibly due to viral interference and competitive advantage of SARS-CoV-2 in modulating the host immunity. Further detailed research is required for the understanding of mechanisms of viral co-infection.

Cangma Huadu granules, a new drug with great potential to treat coronavirus and influenza infections, exert its efficacy through anti-inflammatory and immune regulation

ETHNOPHARMACOLOGICAL RELEVANCE

Coronavirus and influenza virus infection seriously threaten human health. Cangma Huadu Granules (CMHD) is an in-hospital preparation composed of eight traditional Chinese medicines (TCM), which has been clinically used against COVID-19 in China and may be a promising candidate for the treatment of influenza. However, the role of its treatment urgently needs to be studied.

AIM OF THE STUDY

To evaluate the therapeutic effects of CMHD on pneumonia induced by coronavirus (HCoV-229E) and influenza A virus (H1N1/FM1) in mice and explore its mechanism of anti-infection.

MATERIALS AND METHODS

Mice were infected with HCoV-229E or H1N1/FM1 virus through the nasal cavity. CMHD (12.1, 6.05 and 3.03 g/kg/d) or the positive control drugs were administered intragastrically. The lung index and histopathological changes were used to evaluate the therapeutic effect of CMHD. The expression of TNF-α, IL-1β, IL-6 and IL-4 in Serum and the proportion of CD4+ and CD8+ T lymphocytes in peripheral blood were detected to evaluate the anti-inflammatory and immune regulation effects of CMHD, respectively. Furthermore, the levels of p-NF-κBp65/ NF-κB p65, which was the key targets of the NF-κB pathway was analyzed.

RESULTS

In HCoV-229E-induced pneumonia, the lung index was markedly reduced, and lung pathology was improved in mice that treated with CMHD (12.1, 6.05 g/kg/d). Meanwhile, the expression of TNF-α, IL-6 were obviously inhibited, but the expression of IL-4 was significantly increased in CMHD groups. Compared with the model group, CMHD could also markedly upregulate the level of CD4+ and CD8+. Furthermore, CMHD has a markedly effect on inhibit the expression of p-NF-κB p65/NF-κB p65 in the lung. In H1N1-induced pneumonia, the lung index of mice in the CMHD (12.1 g/kg/d) treatment group was lower than that in the model group, and less inflammatory infiltration could be seen in the lung pathological. Moreover, CMHD could also obviously decrease the expression of TNF-α, IL-1β, IL-6, but significantly increase the expression of IL-4. Except for that, CMHD could also markedly downregulate the level of CD4+ and upregulate the level of CD8+ compared with the model group. In addition, CMHD has a markedly effect on inhibit the expression of p-NF-κB p65/NF-κB p65 in the lung.

CONCLUSION

CMHD can significantly combats viral infections caused by HCoV-229E and H1N1, and the mechanism may be related to its multiple functions of anti-inflammatory, immunity regulating and inhibiting NF-κB signal transduction pathway.

Low incidence of human coronavirus among hospitalized children in Novosibirsk city, Russia during pre-pandemic period (2013-2020)

We investigated the incidence of 15 respiratory viruses among 2991 children with acute respiratory infections in Novosibirsk city, Russia, prior to the COVID-19 pandemic (2013-2020). Viral infections were detected in 72.5% cases. The incidence of human coronavirus was 2% (Alphacoronaviruses, 63%; Betacoronaviruses, 37%).

Distribution of spreading viruses during COVID-19 pandemic: Effect of mitigation strategies

Background

The study aimed to evaluate the distribution of circulating respiratory viral pathogens other than severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) during the first year of the coronavirus disease-2019 (COVID-19) pandemic with especially focusing on the effects of the national-based mitigation strategies.

Methods

This single-center study was conducted between March 11, 2020-March 11, 2021. All children who were tested by polymerase chain reaction on nasopharyngeal swabs for SARS-CoV-2 and other common respiratory viral pathogens were included in the study.

Results

A total of 995 children with suspected COVID-19 admitted to the study center. Of these, 513 patients who were tested by polymerase chain reaction for both SARS-CoV-2 and common respiratory viral pathogens were included in the final analysis. Two hundred ninety-five patients were (57.5%) male. The median age was 3 years of age (27 days-17 years). A total of 321 viral pathogens identified in 310 (n: 310/513, 60.4%) patients, and 11 of them (n: 11/310, 3.5%) had co-detection with more than 1 virus. The most common detected virus was rhinovirus (n: 156/513, 30.4%), and SARS-CoV-2 (n: 122/513, 23.8%) followed by respiratory syncytial virus (n: 18/513, 3.5%). The influenza virus was detected in 2 patients (0.4%). A total of 193 patients were negative for both SARS-CoV-2 and other pathogens.

Conclusions

There is a decline in the frequency of all viral pathogens like SARS-CoV-2 in correlation with the national-based mitigation strategies against COVID-19 during the pandemic.

COVID-19 Shuts Doors to Flu but Keeps Them Open to Rhinoviruses

Simple Summary

Ten years have passed since the beginning of the H1N1pdm09 flu pandemic. No sooner had humanity recovered from its consequences than a new attack came—the COVID-19 pandemic. What happens to other respiratory infectious diseases during a global disaster such as the COVID-19 pandemic? The pandemic brought about by the novel SARS-CoV-2 virus has disrupted many well-established epidemiological and pathogenetic relationships, as well as mechanisms affecting infections with other respiratory viruses. The level of circulation of many respiratory pathogens has changed significantly. For instance, global influenza activity is at much lower levels than expected. In many regions, the influenza season has not started. Intriguingly, the COVID-19 pandemic did not substantially affect the spread of human rhinoviruses. In this review, the main properties of epidemiologically significant respiratory viruses such as SARS-CoV-2, influenza virus, and human rhinovirus are described.

Abstract

It is well known that rhinoviruses are distributed across the globe and are the most common cause of the common cold in all age groups. Rhinoviruses are widely considered to be harmless because they are generally perceived as respiratory viruses only capable of causing mild disease. However, they may also infect the lower respiratory tract, inducing chronic obstructive pulmonary disease and exacerbations of asthma, bronchiolitis, etc. The role of rhinoviruses in pathogenesis and the epidemiological process is underestimated, and they need to be intensively studied. In the light of recent data, it is now known that rhinoviruses could be one of the key epidemiological barriers that may influence the spread of influenza and novel coronaviruses. It has been reported that endemic human rhinoviruses delayed the development of the H1N1pdm09 influenza pandemic through viral interference. Moreover, human rhinoviruses have been suggested to block SARS-CoV-2 replication in the airways by triggering an interferon response. In this review, we summarized the main biological characteristics of genetically distinct viruses such as rhinoviruses, influenza viruses, and SARS-CoV-2 in an attempt to illuminate their main discrepancies and similarities. We hope that this comparative analysis will help us to better understand in which direction research in this area should move.

Differential T-Cell Reactivity to Endemic Coronaviruses and SARS-CoV-2 in Community and Health Care Workers

Herein we measured CD4+ T-cell responses against common cold coronaviruses (CCC) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in high-risk health care workers (HCW) and community controls. We observed higher levels of CCC-reactive T cells in SARS-CoV-2-seronegative HCW compared to community donors, consistent with potential higher occupational exposure of HCW to CCC. We further show that SARS-CoV-2 T-cell reactivity of seronegative HCW was higher than community controls and correlation between CCC and SARS-CoV-2 responses is consistent with cross-reactivity and not associated with recent in vivo activation. Surprisingly, CCC T-cell reactivity was decreased in SARS-CoV-2-infected HCW, suggesting that exposure to SARS-CoV-2 might interfere with CCC responses, either directly or indirectly. This result was unexpected, but consistently detected in independent cohorts derived from Miami and San Diego. CD4+ T-cell responses against common cold coronaviruses (CCC) are elevated in SARS-CoV-2 seronegative high-risk health care workers (HCW) compared to COVID-19 convalescent HCW, suggesting that exposure to SARS-CoV-2 might interfere with CCC responses and/or cross-reactivity associated with a protective effect.

Untangling the Intricacies of Infection, Thrombosis, Vaccination, and Antiphospholipid Antibodies for COVID-19

Advanced SARS-CoV-2 infections not uncommonly associate with the occurrence of silent or manifest thrombotic events which may be found as focal or systemic disease. Given the potential complexity of COVID-19 illnesses, a multifactorial causation is likely, but several studies have focused on infection-induced coagulopathy. Procoagulant states are commonly found in association with the finding of antiphospholipid antibodies. The correlation of the latter with thrombosis and/or clinical severity remains controversial. Although measures of antiphospholipid antibodies most commonly include assessments for lupus anticoagulant, anticardiolipin, and anti-ß2-glycoprotein-I antibodies, lesser common antibodies have been detected, and there remains speculation that other yet undiscovered autoimmune thrombotic events may yet be found. The recent discovery of post-vaccination thromboses associated with platelet factor 4 antibody has created another level of concern. The pathogenesis of antiphospholipid antibodies and their role in COVID-19-related thrombosis deserves further attention. The multifactorial nature of thrombosis associated with both infection and vaccination should continue to be studied as new events unfold. Even if a cause-and-effect relationship is variable at best, such dedicated research is likely to generate other valuable insights that are applicable to medicine generally.

Passive Immunity Should and Will Work for COVID-19 for Some Patients

In the absence of effective antiviral chemotherapy and still in the context of emerging vaccines for severe acute respiratory syndrome-CoV-2 infections, passive immunotherapy remains a key treatment and possible prevention strategy. What might initially be conceived as a simplified donor-recipient process, the intricacies of donor plasma, IV immunoglobulins, and monoclonal antibody modality applications are becoming more apparent. Key targets of such treatment have largely focused on virus neutralization and the specific viral components of the attachment Spike protein and its constituents (e.g., receptor binding domain, N-terminal domain). The cumulative laboratory and clinical experience suggests that beneficial protective and treatment outcomes are possible. Both a dose- and a time-dependency emerge. Lesser understood are the concepts of bioavailability and distribution. Apart from direct antigen binding from protective immunoglobulins, antibody effector functions have potential roles in outcome. In attempting to mimic the natural but variable response to infection or vaccination, a strong functional polyclonal approach attracts the potential benefits of attacking antigen diversity, high antibody avidity, antibody persistence, and protection against escape viral mutation. The availability and ease of administration for any passive immunotherapy product must be considered in the current climate of need. There is never a perfect product, but yet there is considerable room for improving patient outcomes. Given the variability of human genetics, immunity, and disease, and given the nuances of the virus and its potential for change, passive immunotherapy can be developed that will be effective for some but not all patients. An understanding of such patient variability and limitations is just as important as the understanding of the direct interactions between immunotherapy and virus.

The Complexity of Co-Infections in the Era of COVID-19

The current frequency of COVID-19 in a pandemic era ensures that co-infections with a variety of co-pathogens will occur. Generally, there is a low rate of bonafide co-infections in early COVID-19 pulmonary infection as currently appreciated. Reports of high co-infection rates must be tempered by limitations in current diagnostic methods since amplification technologies do not necessarily confirm live pathogen and may be subject to considerable laboratory variation. Some laboratory methods may not exclude commensal microbes. Concurrent serodiagnoses have long been of concern for accuracy in these contexts. Presumed virus co-infections are not specific to COVID-19. The association of influenza viruses and SARS-CoV-2 in co-infection has been considerably variable during influenza season. Other respiratory virus co-infections have generally occurred in less than 10% of COVID-19 patients. Early COVID-19 disease is more commonly associated with bacterial co-pathogens that typically represent usual respiratory micro-organisms. Late infections, especially among severe clinical presentations, are more likely to be associated with nosocomial or opportunistic pathogens given the influence of treatments that can include antibiotics, antivirals, immunomodulating agents, blood products, immunotherapy, steroids, and invasive procedures. As anticipated, hospital care carries risk for multi-resistant bacteria. Overall, co-pathogen identification is linked with longer hospital stay, greater patient complexity, and adverse outcomes. As for other viral infections, a general reduction in the use of empiric antibiotic treatment is warranted. Further insight into co-infections with COVID-19 will contribute overall to effective antimicrobial therapies and disease control.

In pursuit of the right tail for the COVID-19 incubation period

Definition of the incubation period for COVID-19 is critical for implementing quarantine and thus infection control. Whereas the classical definition relies on the time from exposure to time of first symptoms, a more practical working definition is the time from exposure to time of first live virus excretion. For COVID-19, average incubation period times commonly span 5–7 days which are generally longer than for most typical other respiratory viruses. There is considerable variability reported however for the late right-hand statistical distribution. A small but yet epidemiologically important subset of patients may have the late end of the incubation period extend beyond the 14 days that is frequently assumed. Conservative assumptions of the right tail end distribution favor safety, but pragmatic working modifications may be required to accommodate high rates of infection and/or healthcare worker exposures. Despite the advent of effective vaccines, further attention and study in these regards are warranted. It is predictable that vaccine application will be associated with continued confusion over protection and its longevity. Measures for the application of infectivity will continue to be extremely relevant.

A Comprehensive Analysis of Maternal and Newborn Disease and Related Control for COVID-19

The maternal-fetal/newborn unit is established at risk for COVID-19 infection. This narrative review summarizes the contemporary and cumulative publications which detail maternal infection, antenatal and newborn infections, and maternal/fetal/newborn management and prevention. There is a wide spectrum of maternal disease, but the potential for severe disease albeit in a minority is confirmed. COVID-19 carries risk for preterm delivery. Pregnant females can suffer multisystem disease, and co-morbidities play a significant role in risk. Congenital infection has been supported by several anecdotal reports, but strong confirmatory data are few. No typical congenital dysmorphisms are evident. Nevertheless, placental vascular compromise must be considered a risk for the fetus during advanced maternal infections. Clinical manifestations of newborn infection have been mild to moderate and relatively uncommon. Proven antiviral therapy is of yet lacking. The mode of delivery is a medical decision that must include patient risk assessment and patient directives. Both presymptomatic and asymptomatic mothers and offspring can complicate infection control management with the potential for spread to others in several regards. In the interim, infections of the maternal-fetal-newborn unit must be taken seriously both for the disease so caused and the potential for further dissemination of disease.

Differential T cell reactivity to seasonal coronaviruses and SARS-CoV-2 in community and health care workers

Herein we measured CD4+ T cell responses against common cold corona (CCC) viruses and SARS-CoV-2 in high-risk health care workers (HCW) and community controls. We observed higher levels of CCC reactive T cells in SARS-CoV-2 seronegative HCW compared to community donors, consistent with potential higher occupational exposure of HCW to CCC. We further show that SARS-CoV-2 reactivity of seronegative HCW was higher than community controls and correlation between CCC and SARS-CoV-2 responses is consistent with cross-reactivity and not associated with recent in vivo activation. Surprisingly, CCC reactivity was decreased in SARS-CoV-2 infected HCW, suggesting that exposure to SARS-CoV-2 might interfere with CCC responses, either directly or indirectly. This result was unexpected, but consistently detected in independent cohorts derived from Miami and San Diego.

Applying Immune Instincts and Maternal Intelligence from Comparative Microbiology to COVID-19

New data specific to COVID-19 are emerging quickly on key issues of immunity and prevention, but past research in coronavirology and for other human pathogens (e.g., Mycoplasma pneumoniae) has been available and of great relevance. Considerable study of endemic human coronaviruses has shown that neutralizing antibody correlates with protection, but effective clinical protection is variable for subsequent virus exposure. Animal coronavirus research has emphasized the importance of local mucosal protection (especially IgA) and systemic responses. Animal model and human post-infection studies for SARS-CoV and MERS-CoV are largely corroborative. Whether for passive therapeutic strategies or vaccination, these findings provide a template for COVID-19. Many approaches to vaccination have emerged, and there may be more than one vaccine that will be applied, but individualized obstacles and concerns for administration, efficacy, and safety are inevitable. Regardless of safeguards or promises that may be understood from laboratory or vertebrate experiments, observations from large-scale human trials will ultimately prove to shape the medical future. Focus on common mucosal immunity can be underrated, and equally or more, focus on lactogenic immunity may be underestimated. In understanding both passive immunity and protection, the body is already primed to educate us with decisions of what constitutes protection and harm. This review provides key insights that drive hypotheses into how the instinct of immunity and the intelligence of the maternal component of the common mucosal immune system has already guided us and may continue to do so effectively into a bright and safe future.