Overview of autoantibodies in COVID-19 convalescents.

Accumulating evidence shows that SARS-CoV-2 can potentially trigger autoimmune processes, which can be responsible for the long-term consequences of COVID-19. Therefore, this paper aims to review the autoantibodies reported in COVID-19 convalescents. Six main groups were distinguished: (i) autoantibodies against components of the immune system, (ii) autoantibodies against components of the cardiovascular system, (iii) thyroid autoantibodies, (iv) autoantibodies specific for rheumatoid diseases, (v) antibodies against G-protein coupled receptors, and (vi) other autoantibodies. The evidence reviewed here clearly highlights that SARS-CoV-2 infection may induce humoral autoimmune responses. However, the available studies share number of limitations, such as: (1) the sole presence of autoantibodies does not necessarily implicate the clinically-relevant risks, (2) functional investigations were rarely performed and it is often unknown whether observed autoantibodies are pathogenic, (3) the control seroprevalence, in healthy, noninfected individuals was often not reported; thus it is sometimes unknown whether the detected autoantibodies are the result of SARS-CoV-2 infection or the accidental post-COVID-19 detection, (4) the presence of autoantibodies was rarely correlated with symptoms of the post-COVID-19 syndrome, (5) the size of the studied groups were often small, (6) the studies focused predominantly on adult populations, (7) age- and sex-related differences in seroprevalence of autoantibodies were rarely explored, (8) genetic predispositions that may be involved in generation of autoantibodies during SARS-CoV-2 infections were not investigated, and (9) the autoimmune reactions following infection with SARS-CoV-2 variants that vary in the clinical course of infection remain unexplored. Further longitudinal studies are advocated to assess the link between identified autoantibodies and particular clinical outcomes in COVID-19 convalescents.

Guillain-Barré syndrome and COVID-19 vaccines: focus on adenoviral vectors.

COVID-19 vaccination is a life-saving intervention. However, it does not come up without a risk of rare adverse events, which frequency varies between vaccines developed using different technological platforms. The increased risk of Guillain-Barré syndrome (GBS) has been reported for selected adenoviral vector vaccines but not for other vaccine types, including more widely used mRNA preparations. Therefore, it is unlikely that GBS results from the cross-reactivity of antibodies against the SARS-CoV-2 spike protein generated after the COVID-19 vaccination. This paper outlines two hypotheses according to which increased risk of GBS following adenoviral vaccination is due to (1) generation of anti-vector antibodies that may cross-react with proteins involved in biological processes related to myelin and axons, or (2) neuroinvasion of selected adenovirus vectors to the peripheral nervous system, infection of neurons and subsequent inflammation and neuropathies. The rationale behind these hypotheses is outlined, advocating further epidemiological and experimental research to verify them. This is particularly important given the ongoing interest in using adenoviruses in developing vaccines against various infectious diseases and cancer immunotherapeutics.

Vaccination of Ukrainian Refugees: Need for Urgent Action.

The unprovoked aggression of Russian military forces on Ukraine in February 2022 has caused a high influx of refugees, including children, to neighboring countries, particularly Poland. This caused additional pressures on the healthcare system and the need to meet challenges for public health, such as those related to infectious diseases. Here, we discuss the potential epidemiological risks associated with the war-induced influx of refugees (coronavirus disease 2019, measles, pertussis, tetanus, and poliomyelitis) and highlight the need for their swift management through institutional support, educational campaigns, counteracting antiscience misinformation, and pursuing vaccinations of refugees but also improving or maintaining good levels of immunization in populations of countries welcoming them. These are necessary actions to avoid overlapping of war and infectious diseases and associated public health challenges.

Association between the Seroprevalence of Antibodies against Seasonal Alphacoronaviruses and SARS-CoV-2 Humoral Immune Response, COVID-19 Severity, and Influenza Vaccination

The present study assesses the seroprevalence of antibodies against seasonal human alphacoronaviruses 229E and NL63 among adult patients infected with SARS-CoV-2, and its association with the humoral response to SARS-CoV-2 infection and its severity, and influenza vaccination. A serosurvey was conducted to quantify the presence of IgG antibodies against the nucleocapsid of 229E (anti-229E-N) and NL63 (anti-NL63-N), and anti-SARS-CoV-2 IgG antibodies (against nucleocapsid, receptor-binding domain, S2 domain, envelope, and papain-like protease) for 1313 Polish patients. The seroprevalence of anti-229E-N and anti-NL63 in the studied cohort was 3.3% and 2.4%. Seropositive individuals had a higher prevalence of anti-SARS-CoV-2 IgG antibodies, higher titers of the selected anti-SARS-CoV2 antibodies, and higher odds of an asymptomatic SARS-CoV-2 infection (OR = 2.5 for 229E and OR = 2.7 for NL63). Lastly, the individuals vaccinated against influenza in the 2019/2020 epidemic season had lower odds of seropositivity to 229E (OR = 0.38). The 229E and NL63 seroprevalence was below the expected pre-pandemic levels (up to 10%), likely due to social distancing, increased hygiene, and face masking. The study also suggests that exposure to seasonal alphacoronaviruses may improve humoral responses to SARS-CoV-2 while decreasing the clinical significance of its infection. It also adds to accumulating evidence of the favorable indirect effects of influenza vaccination. However, the findings of the present study are of a correlative nature and thereby do not necessarily imply causation.

The pit latrine paradox in low-income settings: A sanitation technology of choice or a pollution hotspot?

Pit latrines are widely promoted to improve sanitation in low-income settings, but their pollution and health risks receive cursory attention. The present narrative review presents the pit latrine paradox; (1) the pit latrine is considered a sanitation technology of choice to safeguard human health, and (2) conversely, pit latrines are pollution and health risk hotspots. Evidence shows that the pit latrine is a 'catch-all' receptacle for household disposal of hazardous waste, including; (1) medical wastes (COVID-19 PPE, pharmaceuticals, placenta, used condoms), (2) pesticides and pesticide containers, (3) menstrual hygiene wastes (e.g., sanitary pads), and (4) electronic wastes (batteries). Pit latrines serve as hotspot reservoirs that receive, harbour, and then transmit the following into the environment; (1) conventional contaminants (nitrates, phosphates, pesticides), (2) emerging contaminants (pharmaceuticals and personal care products, antibiotic resistance), and (3) indicator organisms, and human bacterial and viral pathogens, and disease vectors (rodents, houseflies, bats). As greenhouse gas emission hotspots, pit latrines contribute 3.3 to 9.4 Tg/year of methane, but this could be an under-estimation. Contaminants in pit latrines may migrate into surface water, and groundwater systems serving as drinking water sources and pose human health risks. In turn, this culminates into the pit latrine-groundwater-human continuum or connectivity, mediated via water and contaminant migration. Human health risks of pit latrines, a critique of current evidence, and current and emerging mitigation measures are presented, including isolation distance, hydraulic liners/ barriers, ecological sanitation, and the concept of a circular bioeconomy. Finally, future research directions on the epidemiology and fate of contaminants in pit latrines are presented. The pit latrine paradox is not meant to downplay pit latrines' role or promote open defaecation. Rather, it seeks to stimulate discussion and research to refine the technology to enhance its functionality while mitigating pollution and health risks.

Retrospective Analysis of the Effectiveness of Remdesivir in COVID-19 Treatment during Periods Dominated by Delta and Omicron SARS-CoV-2 Variants in Clinical Settings.

Continuous evaluation of real-world treatment effectiveness of COVID-19 medicines is required due to the ongoing evolution of SARS-CoV-2 and the possible emergence of resistance. Therefore, this study aimed to analyze, in a retrospective manner, the outcomes in patients hospitalized with COVID-19 during the pandemic waves dominated by Delta and Omicron variants and treated with remdesivir (RDV) (n = 762) in comparison to a demographically and clinically matched group not treated with any antivirals (n = 1060). A logistic regression analysis revealed that RDV treatment was associated with a significantly lower risk of death during both Delta wave (OR = 0.42, 95%CI: 0.29-0.60; p < 0.0001) and Omicron-dominated period (OR = 0.56, 95%CI: 0.35-0.92; p = 0.02). Moreover, RDV-treated groups were characterized by a lower percentage of patients requiring mechanical ventilation, but the difference was not statistically significant. This study is the first real-world evidence that RDV remains effective during the dominance of more pathogenic SARS-CoV-2 variants and those that cause a milder course of the disease, and continues to be an essential element of COVID-19 therapy.

Association between the Seroprevalence of Antibodies against Seasonal Alphacoronaviruses and SARS-CoV-2 Humoral Immune Response, COVID-19 Severity, and Influenza Vaccination.

The present study assesses the seroprevalence of antibodies against seasonal human alphacoronaviruses 229E and NL63 among adult patients infected with SARS-CoV-2, and its association with the humoral response to SARS-CoV-2 infection and its severity, and influenza vaccination. A serosurvey was conducted to quantify the presence of IgG antibodies against the nucleocapsid of 229E (anti-229E-N) and NL63 (anti-NL63-N), and anti-SARS-CoV-2 IgG antibodies (against nucleocapsid, receptor-binding domain, S2 domain, envelope, and papain-like protease) for 1313 Polish patients. The seroprevalence of anti-229E-N and anti-NL63 in the studied cohort was 3.3% and 2.4%. Seropositive individuals had a higher prevalence of anti-SARS-CoV-2 IgG antibodies, higher titers of the selected anti-SARS-CoV2 antibodies, and higher odds of an asymptomatic SARS-CoV-2 infection (OR = 2.5 for 229E and OR = 2.7 for NL63). Lastly, the individuals vaccinated against influenza in the 2019/2020 epidemic season had lower odds of seropositivity to 229E (OR = 0.38). The 229E and NL63 seroprevalence was below the expected pre-pandemic levels (up to 10%), likely due to social distancing, increased hygiene, and face masking. The study also suggests that exposure to seasonal alphacoronaviruses may improve humoral responses to SARS-CoV-2 while decreasing the clinical significance of its infection. It also adds to accumulating evidence of the favorable indirect effects of influenza vaccination. However, the findings of the present study are of a correlative nature and thereby do not necessarily imply causation.

mRNA vaccines: The future of prevention of viral infections?

Messenger RNA (mRNA) vaccines against COVID-19 are the first authorized biological preparations developed using this platform. During the pandemic, their administration has been proven to be a life-saving intervention. Here, we review the main advantages of using mRNA vaccines, identify further technological challenges to be met during the development of the mRNA platform, and provide an update on the clinical progress on leading mRNA vaccine candidates against different viruses that include influenza viruses, human immunodeficiency virus 1, respiratory syncytial virus, Nipah virus, Zika virus, human cytomegalovirus, and Epstein-Barr virus. The prospects and challenges of manufacturing mRNA vaccines in low-income countries are also discussed. The ongoing interest and research in mRNA technology are likely to overcome some existing challenges for this technology (e.g., related to storage conditions and immunogenicity of some components of lipid nanoparticles) and enhance the portfolio of vaccines against diseases for which classical formulations are already authorized. It may also open novel pathways of protection against infections and their consequences for which no safe and efficient immunization methods are currently available.

Variability in the Clinical Course of COVID-19 in a Retrospective Analysis of a Large Real-World Database.

The COVID-19 pandemic proceeds in waves, with variable characteristics of the clinical picture resulting from the evolution of the SARS-CoV-2 virus. This study aimed to compare the epidemiological characteristics, symptomatology, and outcomes of the disease in patients hospitalized for COVID-19 during periods of different variants dominance. Comparing the periods of dominance of variants preceding the Delta variant, the Delta period was characterized by a higher share of hospitalized females, less frequent comorbidities among patients, and a different age distribution. The lowest need for oxygen therapy and mechanical ventilation was observed under Omicron dominance. The triad of classic COVID-19 symptoms, cough, fever, dyspnoea, and fatigue, were most prevalent during the Delta period, and significantly less common under the Omicron dominance. During the Omicron period, nearly twice as many patients as in the previous periods could be discharged from the hospital within 7 days; the overall 28-day mortality was significantly lower compared to that of the Delta period. It also did not differ between periods that were dominated by the BA.1 and BA.2 subvariants. The study indicates that the Omicron SARS-CoV-2 variant that dominated between January and June 2022 caused a disease which resembled the common cold, and was caused by seasonal alpha and beta-coronaviruses with a low pathogenicity for humans. However, one should note that this effect may not only have been related to biological features of the Omicron lineage, but may additionally have been driven by the increased levels of immunization through natural infections and vaccinations, for which we could not account for due to a lack of sufficient data.

COVID-19 vaccinations and rates of infections, hospitalizations, ICU admissions, and deaths in Europe during SARS-CoV-2 Omicron wave in the first quarter of 2022.

The vaccination campaigns brought hope to minimizing the coronavirus disease 2019 (COVID-19) burden. However, the emergence of novel, highly transmissible Omicron lineage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the waning of neutralizing antibodies a few months after vaccination has brought concerns over the vaccine efficacy. The present work analyzed the relationships between COVID-19 vaccine coverage (completion of primary course and booster dose intake) in the European Economic Area and rates of infection, hospitalizations, admissions to intensive care units (ICU), and deaths during the Omicron wave in the first quarter of 2022 (January-April). As demonstrated, infection rates were not correlated to vaccine coverage in any considered month. For January and February, the rates of hospitalizations, intensive care unit (ICU) admissions, and death due to COVID-19 were strongly negatively correlated (r =- 0.54 to -0.82) with the percentage of individuals who completed initial vaccination protocol and the percentage of those who received a booster dose. However, in March and April, the percentage of the population with primary vaccination course correlated negatively only with ICU admissions (r = -0.77 and -0.46, respectively). The uptake of boosters in March still remained in significant negative correlation with hospitalizations (r = -0.45), ICU admissions (r = -0.70) and deaths due to COVID-19 (r = -0.37), although in April these relationships were no longer observed. The percentage of individuals with confirmed SARS-CoV-2 infection did not correlate with the pandemic indices for any considered month. The study indicates that COVID-19 vaccination, including booster administration, was beneficial in decreasing the overwhelming of healthcare systems during the Omicron wave, but novel vaccine strategies may be required in the long term to enhance the effectiveness and durability of vaccine-induced protection during future waves of SARS-CoV-2 infections.

IgG autoantibodies against ACE2 in SARS-CoV-2 infected patients.

How frequently autoantibodies against angiotensin-converting enzyme 2 (ACE2) occur in patients infected by SARS-CoV-2 is understudied and limited to investigations on a small sample size. The presence of these antibodies may contribute to the long-lasting effects of COVID-19 observed in some individuals, particularly if IgG-class antibodies would emerge in patients. This study assessed the prevalence of IgG autoantibodies against ACE2 in 1139 patients infected with SARS-CoV-2 and examined their relationship with severity, demographic characteristics, and status of vaccination against influenza. The overall prevalence of anti-ACE IgG antibodies in our cohort was 1.5%. Most of these individuals were men (76.5%) and underwent mild COVID-19, but some severe and asymptomatic cases were also observed. Patients with severe infection had twofold higher titers than mild and asymptomatic cases. Age, comorbidities, and influenza vaccination status were not related to antibody prevalence. The prevalence of IgG anti-SARS-CoV-2 antibodies (against nucleocapsid protein and S2 subunit, but not against receptor-binding domain) was higher in the subset with ACE2 autoantibodies. Further research is required to understand the potential spectrum and duration of effects of IgG autoantibodies against ACE2 in patients after SARS-CoV-2 infection, particularly concerning long COVID-19.

The association of airborne particulate matter and benzo[a]pyrene with the clinical course of COVID-19 in patients hospitalized in Poland.

Air pollution can adversely affect the immune response and increase the severity of the viral disease. The present study aimed to explore the relationship between symptomatology, clinical course, and inflammation markers of adult patients with coronavirus disease 2019 (COVID-19) hospitalized in Poland (n = 4432) and air pollution levels, i.e., mean 24 h and max 24 h level of benzo(a)pyrene (B(a)P) and particulate matter <10 µm (PM10) and <2.5 µm (PM2.5) during a week before their hospitalization. Exposures to PM2.5 and B(a)P exceeding the limits were associated with higher odds of early respiratory symptoms of COVID-19 and hyperinflammatory state: interleukin-6 > 100 pg/mL, procalcitonin >0.25 ng/mL, and white blood cells count >11 × 103/mL. Except for the mean 24 h PM10 level, the exceedance of other air pollution parameters was associated with increased odds for oxygen saturation <90%. Exposure to elevated PM2.5 and B(a)P levels increased the odds of oxygen therapy and death. This study evidences that worse air quality is related to increased severity of COVID-19 and worse outcome in hospitalized patients. Mitigating air pollution shall be an integral part of measures undertaken to decrease the disease burden during a pandemic of viral respiratory illness.

Differences between the course of SARS-CoV-2 infections in the periods of the Delta and Omicron variant dominance in Poland.

INTRODUCTION: Up to now, COVID­19 caused more than 6 million deaths worldwide. So far, 5 variants of concerns have been identified, with Delta and Omicron being the subject of our analysis. OBJECTIVES: We aimed to compare baseline characteristics and outcomes of patients hospitalized during the Delta and Omicron predominance in Poland. PATIENTS AND METHODS: The study population consisted of 2225 patients divided into 2 groups depending on the variant with which they were infected during the corresponding period of the pandemic. RESULTS: During the Delta wave, the median age of patients was significantly lower (65 vs 73 years; P <0.001), and the cohort was significantly less burdened with comorbidities than during the Omicron surge. The Omicron­infected patients presented significantly less often in an unstable symptomatic state with SpO2 equal to or below 90% on admission (49.9% for Delta vs 29.9% for Omicron; P <0.001). Regardless of the pandemic period, the 2 most common early symptoms of COVID­19 were fever and cough. In­hospital treatment consisted of antiviral drugs, more frequently used in the Omicron wave, and immunomodulatory drugs, more frequently used during the Delta wave. The risk of mechanical ventilation was significantly lower in the patients infected with the Omicron variant (7.2% for Delta vs 3.1% for Omicron; P <0.001). For the age group above 80 years old, the risk of death was significantly higher during the Delta wave than during the Omicron wave. The risk of death was significantly lower in the patients treated with antiviral drugs regardless of the pandemic wave. CONCLUSIONS: The Delta variant is associated with a more severe clinical course of the disease and a higher risk of death than the Omicron variant.

Grappling with (re)-emerging infectious zoonoses: Risk assessment, mitigation framework, and future directions

Low-income countries (LICs) in Africa, southeast Asia, Latin America, and the Caribbeans constitute potential hotspots for future outbreaks of zoonoses. A comprehensive framework on risk drivers, assessment, and mitigation in LICs is lacking. This paper presents the nature, history, risk factors, and drivers of zoonoses in LICs. A Quantitative Microbial Risk Assessment and Hazard Analysis of Critical Control Points are proposed for assessing human health risks. The mitigation framework entails: (i) learning from the COVID-19 pandemic, (ii) the precautionary principle, (iii) raising public and stakeholder awareness, and (iv) the One World, One Health concept. Future perspectives are discussed on: (i) curbing poaching and illicit wildlife trade, (ii) translating the ‘One Health’ concept to practice, (iii) the dilemma of dealing with wildlife hosts of zoonoses, including the morality and ethics of culling versus non-culling, (iv) the challenges of source tracking and apportionment of zoonoses, and (v) decision scenarios accounting for the high human health risks and the high uncertainty in current evidence. Future directions on zoonoses include: (i) the occurrence of antimicrobial resistance, (ii) environmental reservoirs and hosts, (iii) the development of tools for source tracking and apportionment, and (iv) host-receptor-pathogen interactions. Funding models and the application of novel tools, i.e., game theory, genomics, shell disorder analysis, and geographical information systems, are discussed. The proposed framework enables a better understanding of the key risk drivers, assessment, and mitigation in LICs. Further work is needed to test and validate the framework and develop generic lessons for risk assessment and mitigation in LICs.

Relationship between Humoral Response in COVID-19 and Seasonal Influenza Vaccination.

There is evidence that vaccination against seasonal influenza can improve innate immune responses to COVID-19 and decrease disease severity. However, less is known about whether it could also impact the humoral immunity in SARS-CoV-2 infected patients. The present study aimed to compare the SARS-CoV-2 specific humoral responses (IgG antibodies against nucleocapsid; anti-N, receptor binding domain; anti-RBD, subunit S2; anti-S2, and envelope protein; anti-E) between non-hospitalized, COVID-19 unvaccinated, and mild COVID-19 convalescent patients who were and were not vaccinated against influenza during the 2019/2020 epidemic season (n = 489 and n = 292, respectively). The influenza-vaccinated group had significantly higher frequency and titers of anti-N antibodies (75 vs. 66%; mean 559 vs. 520 U/mL) and anti-RBD antibodies (85 vs. 76%; mean 580 vs. 540 U/mL). The prevalence and concentrations of anti-S2 and anti-E antibodies did not differ between groups (40-43%; mean 370-375 U/mL and 1.4-1.7%; mean 261-294 U/mL) and were significantly lower compared to those of anti-RBD and anti-N. In both groups, age, comorbidities, and gender did not affect the prevalence and concentrations of studied antibodies. The results indicate that influenza vaccination can improve serum antibody levels produced in response to SARS-CoV-2 infection.

Real-world experience with molnupiravir during the period of SARS-CoV-2 Omicron variant dominance.

BACKGROUND: The real-world effectiveness of molnupiravir (MOL) during the dominance of Omicron SARS-CoV-2 lineage is urgently needed since the available data relate to the period of circulation of other viral variants. Therefore, this study assessed the efficacy of MOL in patients hospitalized for COVID-19 in a real-world clinical practice during the wave of Omicron infections. METHODS: Among 11,822 patients hospitalized after 1 March 2020 and included in the SARSTer national database, 590 were treated between 1 January and 30 April 2022, a period of dominance of the Omicron SARS-CoV-2 variant. MOL was administered to 203 patients, whereas 387 did not receive any antiviral regimen. Both groups were similar in terms of sex, BMI and age allowing for direct comparisons. RESULTS: Patients who did not receive antiviral therapy significantly more often required the use of Dexamethasone and Baricitinib. Treatment with MOL resulted in a statistically significant reduction in mortality during the 28-day follow-up (9.9 vs. 16.3%), which was particularly evident in the population of patients over 80 years of age treated in the first 5 days of the disease (14.6 vs. 35.2%). MOL therapy did not affect the frequency of the need for mechanical ventilation, but patients treated with MOL required oxygen supplementation less frequently than those without antivirals (31.7 vs. 49.2%). The time of hospitalization did not differ between groups. CONCLUSIONS: The use of molnupiravir in patients hospitalized for COVID-19 during the dominance of Omicron variant reduced mortality. This effect is particularly evident in patients over 80 years of age.

COVID-19 Vaccine Booster Strategies for Omicron SARS-CoV-2 Variant: Effectiveness and Future Prospects.

In the light of the lack of authorized COVID-19 vaccines adapted to the Omicron variant lineage, the administration of the first and second booster dose is recommended. It remains important to monitor the efficacy of such an approach in order to inform future preventive strategies. The present paper summarizes the research progress on the effectiveness of the first and second booster doses of COVID-19. It also discusses the potential approach in vaccination strategies that could be undertaken to maintain high levels of protection during the waves of SARS-CoV-2 infections. Although this approach can be based, with some shortcomings, on the first-generation vaccines, other vaccination strategies should be explored, including developing multiple antigen-based (multivariant-adapted) booster doses with enhanced durability of immune protection, e.g., through optimization of the half-life of generated antibodies.

Updates in Management of SARS-CoV-2 Infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide since the beginning of 2020 [...].