Vaccines for the Elderly and Vaccination Programs in Europe and the United States.

The share of the elderly population is growing worldwide as life expectancy increases. Immunosenescence and comorbidities increase infectious diseases' morbidity and mortality in older adults. Here, we aimed to summarize the latest findings on vaccines for the elderly against herpes zoster, influenza, respiratory syncytial virus (RSV), COVID-19, and pneumococcal disease and to examine vaccine recommendation differences for this age group in Europe and the United States. PubMed was searched using the keywords "elders" and "vaccine" alongside the disease/pathogen in question and paraphrased or synonymous terms. Vaccine recommendations were also sought in the European and US Centers for Disease Control and Prevention databases. Improved vaccines, tailored for the elderly, mainly by using novel adjuvants or by increasing antigen concentration, are now available. Significant differences exist between immunization policies, especially between European countries, in terms of the recipient's age, number of doses, vaccination schedule, and implementation (mandatory or recommended). Understanding the factors that influence the immune response to vaccination in the elderly may help to design vaccines that offer long-term protection for this vulnerable age group. A consensus-based strategy in Europe could help to fill the gaps in immunization policy in the elderly, particularly regarding vaccination against RSV and pneumococcus.

The Molecular Basis of Olfactory Dysfunction in COVID-19 and Long COVID.

Olfactory dysfunction (OD) is not uncommon following viral infection. Herein, we explore the interplay of host genetics with viral correlates in coronavirus disease 2019 (COVID-19)- and long COVID-related OD, and its diagnosis and treatment that remain challenging. Two genes associated with olfaction, UGT2A1 and UGT2A2, appear to be involved in COVID-19-related anosmia, a hallmark symptom of acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), particularly in the early stages of the pandemic. SARS-CoV-2 infects olfactory support cells, sustentacular and Bowman gland cells, that surround olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) where the initial step of odor detection takes place. Anosmia primarily arises from the infection of support cells of the OE, followed by the deciliation and disruption of OE integrity, typically without OSN infection. Through the projected axons of OSNs, the virus could theoretically reach the olfactory bulb and brain, but current evidence points against this route. Intriguingly, SARS-CoV-2 infection of support cells leads to profound alterations in the nuclear architecture of OSNs, leading to the downregulation of odorant receptor-related genes, e.g., of Adcy3. Viral factors associated with the development of OD include spike protein aminoacidic changes, e.g., D614G, the first substitution that was selected early during SARS-CoV-2 evolution. More recent variants of the Omicron family are less likely to cause OD compared to Delta or Alpha, although OD has been associated with a milder disease course. OD is one of the most prevalent post-acute neurologic symptoms of SARS-CoV-2 infection. The tens of millions of people worldwide who have lingering problems with OD wait eagerly for effective new treatments that will restore their sense of smell which adds value to their quality of life.

Investigating ABO Blood Groups and Secretor Status in Relation to SARS-CoV-2 Infection and COVID-19 Severity.

The ABO blood groups, Lewis antigens, and secretor systems are important components of transfusion medicine. These interconnected systems have been also shown to be associated with differing susceptibility to bacterial and viral infections, likely as the result of selection over the course of evolution and the constant tug of war between humans and infectious microbes. This comprehensive narrative review aimed to explore the literature and to present the current state of knowledge on reported associations of the ABO, Lewis, and secretor blood groups with SARS-CoV-2 infection and COVID-19 severity. Our main finding was that the A blood group may be associated with increased susceptibility to SARS-CoV-2 infection, and possibly also with increased disease severity and overall mortality. The proposed pathophysiological pathways explaining this potential association include antibody-mediated mechanisms and increased thrombotic risk amongst blood group A individuals, in addition to altered inflammatory cytokine expression profiles. Preliminary evidence does not support the association between ABO blood groups and COVID-19 vaccine response, or the risk of developing long COVID. Even though the emergency state of the pandemic is over, further research is needed especially in this area since tens of millions of people worldwide suffer from lingering COVID-19 symptoms.

Predominance of Recombinant Norovirus Strains in Greece, 2016-2018.

GII.4 noroviruses have caused the overwhelming majority of norovirus-related gastroenteritis cases during the past two decades. However, a trend towards the emergence of new genotypes and novel GII.4 variants provided the impetus to explore further the changing patterns in norovirus epidemiology during the present study. Genotyping of 60 norovirus strains detected during a period of 33 months (January 2016-October 2018) was performed on the basis of the capsid VP1-coding ORF2 gene sequence. All norovirus strains detected were classified into seven genotypes, six of which belonged to genogroup GII. GII.2 was the dominant genotype till February 2017, whereas GII.4 prevailed thereafter. Most of the GII.4 strains were of the Sydney_2012 variant, whereas five strains could not be classified. Further recombination analysis at the ORF1/ORF2 gene junction revealed that 23 out of 24 strains were recombinant, thereby showcasing the significant role of genetic recombination in norovirus evolution and epidemiology. Continuous genomic surveillance and molecular characterization are essential for tracking norovirus evolution, which could contribute to the elucidation of new aspects of virus-host interactions that potentially affect host morbidity and epidemiology.

SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic.

We are reviewing the current state of knowledge on the virological and immunological correlates of long COVID, focusing on recent evidence for the possible association between the increasing number of SARS-CoV-2 reinfections and the parallel pandemic of long COVID. The severity of reinfections largely depends on the severity of the initial episode; in turn, this is determined both by a combination of genetic factors, particularly related to the innate immune response, and by the pathogenicity of the specific variant, especially its ability to infect and induce syncytia formation at the lower respiratory tract. The cumulative risk of long COVID as well as of various cardiac, pulmonary, or neurological complications increases proportionally to the number of SARS-CoV-2 infections, primarily in the elderly. Therefore, the number of long COVID cases is expected to remain high in the future. Reinfections apparently increase the likelihood of long COVID, but less so if they are mild or asymptomatic as in children and adolescents. Strategies to prevent SARS-CoV-2 reinfections are urgently needed, primarily among older adults who have a higher burden of comorbidities. Follow-up studies using an established case definition and precise diagnostic criteria of long COVID in people with or without reinfection may further elucidate the contribution of SARS-CoV-2 reinfections to the long COVID burden. Although accumulating evidence supports vaccination, both before and after the SARS-CoV-2 infection, as a preventive strategy to reduce the risk of long COVID, more robust comparative observational studies, including randomized trials, are needed to provide conclusive evidence of the effectiveness of vaccination in preventing or mitigating long COVID in all age groups. Thankfully, answers not only on the prevention, but also on treatment options and rates of recovery from long COVID are gradually starting to emerge.

An update on asthma diagnosis.

OBJECTIVE: Asthma imposes a significant health and socioeconomic burden with an average prevalence impacting 5-10% of the global population. The aim of this narrative review is to update the current literature on topics related to asthma diagnosis. DATA SOURCES: Original research articles were identified from PubMed using the search terms "asthma diagnosis" and "asthma misdiagnosis". STUDY SELECTIONS: Recently published articles (n = 51) detailing the diagnosis, misdiagnosis of asthma, and the updated recommendations of the European and international asthma guidelines. RESULTS: Emerging evidence revealed that asthma might represent a rather heterogenous clinical entity with varying underlying molecular mechanisms. Attempts have been made to unravel these traits to better provide accurate diagnosis and a more efficient patient-based management approach. The lack of a gold standard test for asthma diagnosis has contributed to its over- and underdiagnosis. This is problematic, given that overdiagnosis might lead to delay of both diagnosis and prompt treatment of other diseases, while underdiagnosis might substantially impact quality of life due to progression of asthma by increased rate of exacerbations and airway remodeling. In addition to poor asthma control and potential patient harm, asthma misdiagnosis is also associated with excessive costs. As a result, current international guidelines emphasize the need for a standardized approach to diagnosis, including objective measurements prior to treatment. CONCLUSION: Future research is warranted to define the optimal diagnostic and treatable traits approach especially for patients with severe asthma, as they may benefit from the advent of newly targeted asthma management.

Overview of Mpox Outbreak in Greece in 2022-2023: Is It Over?

In May 2022, for the first time, multiple cases of mpox were reported in several non-endemic countries. The first ever case of the disease in Greece was confirmed on 8 June 2022, and a total of 88 cases were reported in the country until the end of April 2023. A multidisciplinary response team was established by the Greek National Public Health Organization (EODY) to monitor and manage the situation. EODY's emergency response focused on enhanced surveillance, laboratory testing, contact tracing, medical countermeasures, and the education of health care providers and the public. Even though management of cases was considered successful and the risk from the disease was downgraded, sporadic cases continue to occur. Here, we provide epidemiological and laboratory features of the reported cases to depict the course of the disease notification rate. Our results suggest that measures for raising awareness as well as vaccination of high-risk groups of the population should be continued.

Clinical outcome in newborns of perinatally COVID-19 infected women.

OBJECTIVE: Maternal COVID-19 infection during pregnancy has been associated with adverse neonatal outcomes, such as prematurity and neonatal morbidity. Those adverse events are mainly attributed to maternal factors, rather than to the neonatal infection itself. Our aim is to add our experience and present the neonatal outcome of neonates born to mothers with perinatal SARS-CoV-2 infection. METHODS: This is a prospective case-control study with data from two Academic Tertiary Referral Hospitals in Greece. Electronic records of all births from SARS-CoV-2 positive mothers between March 2020 and April 2021 were analyzed. Demographic data, the severity of maternal COVID-19 disease, gestational age (GA), mode of delivery, birth weight (BW), need for resuscitation and/or supplemental oxygen and duration of hospitalization were recorded. A comparison with 2:1 matched neonates according to sex, GA, and BW born to SARS-CoV-2 negative mothers during the same period was performed. Chi-square and Mann-Whitney U test were used for categorical and non-categorical variables respectively. RESULTS: A total of eighty-one neonates were born to SARS-CoV-2 positive mothers during this period. Forty-three percent of pregnant mothers were asymptomatic. Median GA and median BW were 38 weeks (Interquantile range (IQR): 36-39 weeks) and 2940 gr (IQR: 2560-3340 gr) respectively. Prematurity was observed in 24.7% of the cases. Only 2 (2.4%) neonates were PCR positive after delivery. SARS-CoV-2 positive women were more likely to undergo Cesarean section. APGAR score at 5 min and the need for resuscitation did not differ between the two groups. In comparison with the control group, neonates born to SARS-CoV-2 positive mothers presented with gastrointestinal symptoms (53.6% vs 5.1%, p-value= <.001) and hospitalization was longer, mostly due to maternal factors. CONCLUSION: In our study neonatal positivity was limited and no vertical transmission was noted. Neonatal outcomes were comparable to the control group. However, the presence of gastrointestinal symptoms in neonates born to PCR-positive women compared to controls needs further investigation.

New­onset neuropsychiatric sequelae and 'long­COVID' syndrome (Review).

The ongoing coronavirus disease 2019 (COVID-19) pandemic has had a widespread impact on individuals' mental health through indirect psychological and social mechanisms, related to factors such as fear of infection or death, social isolation, lack of social support and financial instability. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has also been associated with the development or recurrence of neuropsychiatric symptoms, both during the acute phase, as well as during the post-acute 'long-COVID' phase. In addition to the COVID-19 survivors with a mental health history that are at a high risk of experiencing a range of neuropsychiatric symptoms following resolution of acute COVID-19, there is accumulating evidence that a diagnosis of COVID-19 may also be associated with new-onset neuropsychiatric morbidity among survivors without pre-existing mental health disorders. In particular, studies investigating the incidence of post-acute neuropsychiatric sequelae, based mostly on retrospective cohort study designs and data from national health registries, have reported the development of new-onset manifestations, including depression, anxiety, psychotic symptoms, sleep disturbances and fatigue. Nevertheless, when COVID-19 survivors were compared with SARS-CoV-2-negative controls and especially survivors of other disorders (such as influenza), the findings regarding the risk of incident neuropsychiatric manifestations varied among studies. While there is evidence of an association between SARS-CoV-2 infection and the subsequent occurrence of new-onset neuropsychiatric symptoms, especially among patients with increased disease severity, further research using methodological approaches less susceptible to confounding bias is required to establish causal relationships.

Long COVID and neuropsychiatric manifestations (Review).

There is accumulating evidence in the literature indicating that a number of patients with coronavirus disease 2019 (COVID-19) may experience a range of neuropsychiatric symptoms, persisting or even presenting following the resolution of acute COVID-19. Among the neuropsychiatric manifestations more frequently associated with 'long COVID' are depression, anxiety, post-traumatic stress disorder, sleep disturbances, fatigue and cognitive deficits, that can potentially be debilitating and negatively affect patients' wellbeing, albeit in the majority of cases symptoms tend to improve over time. Despite variations in results obtained from studies using different methodological approaches to define 'long COVID' syndrome, the most widely accepted factors associated with a higher risk of developing neuropsychiatric manifestations include the severity of foregoing COVID-19, the female sex, the presence of comorbidities, a history of mental health disease and an elevation in the levels of inflammatory markers, albeit further research is required to establish causal associations. To date, the pathophysiological mechanisms implicated in neuropsychiatric manifestations of 'long COVID' remain only partially elucidated, while the role of the indirect effects of the COVID-19 pandemic, such as social isolation and uncertainty concerning social, financial and health recovery post-COVID, have also been highlighted. Given the alarming effects of 'long-COVID', interdisciplinary cooperation for the early identification of patients who are at a high risk of persistent neuropsychiatric presentations, beyond COVID-19 recovery, is crucial to ensure that appropriate integrated physical and mental health support is provided, with the aim of mitigating the risks of long-term disability at a societal and individual level.