Are Older People Really More Susceptible to SARS-CoV-2?

The underlying mechanism behind the different outcomes of COVID-19 in children and adults

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has affected hundreds of millions of people globally, resulting in millions of deaths. During this pandemic, children have demonstrated greater resistance than adults, exhibiting lower infection rates, reduced mortality, and milder symptoms. Summarizing the differences in resistance between children and adults during COVID-19 can provide insights into protective mechanisms and potential implications for future treatments. In this review, we focused on summarizing and discussing the mechanisms for better protection of children in COVID-19. These protective mechanisms encompass several factors: the baseline expression of cell surface receptor ACE2 and hydrolase TMPRSS2, the impact of complications on COVID-19, and age-related cytokine profiles. Additionally, differences in local and systemic immune responses between children and adults also contribute significantly, particularly interferon responses, heterologous protection from non-COVID-19 vaccinations, and immune status variations influenced by micronutrient levels. The advantageous protection mechanisms of these children may provide insights into the prevention and treatment of COVID-19. Importantly, while age-related metabolic profiles and differential COVID-19 vaccine responses may contribute to protection in children, current comparative research remains limited and requires further investigation.

Impact of vitamin D levels on mortality in older covid-19 vaccinated patients

BACKGROUND

Vitamin D plays a key role in regulating the immune system and vaccine response, and hypovitaminosis D is a known risk factor for mortality. However, its potential influence on mortality in SARS-CoV-2 vaccinated older adults remains underexplored. This study aims to examine survival differences between unvaccinated and vaccinated older adults with varying vitamin D levels, and to assess the impact of vitamin D on mortality.

METHODS

We recruited patients aged 65 and over from the Geriatrics Unit of Azienda Ospedale - Università Padova. Clinical, pharmacological data, including vaccination status and vitamin D levels, were collected at admission, alongside mortality data 12 months post-hospitalization. Participants were divided into three groups: unvaccinated, vaccinated with vitamin D levels of 25-50 nmol/L, and vaccinated with levels > 50 nmol/L.

RESULTS

A total of 126 participants were included (56% women, mean age 83 years). No significant differences were found in COVID-19 severity among the three groups. After 12 months, 24 deaths were recorded: 17% in unvaccinated, 19% in vaccinated with low vitamin D, and 20% in vaccinated with high vitamin D (p = 0.94). Kaplan-Meier curves showed that mortality risk for vaccinated individuals with low vitamin D was similar to unvaccinated patients but significantly higher than vaccinated individuals with high vitamin D (p = 0.04). Vitamin D levels of 25-50 nmol/L were associated with a threefold increased risk of 12-month mortality (HR: 3.79, p < 0.001).

CONCLUSIONS

Vitamin D levels can impact mortality in older vaccinated individuals. Early correction of vitamin D deficiency could potentially enhance outcomes.

Temporal Dynamics and (Para)Clinical Factors Associated With (Long) Viral RNA Shedding in COVID-19 Nonhospitalized Individuals - The COVID-HOME Study

Understanding temporal patterns and determinants of RNA shedding is important to comprehend SARS-CoV-2 transmission and improve biosafety/isolation guidelines. Nonhospitalized SARS-CoV-2-infected individuals and household members were enrolled between March 2020 and June 2021 and followed prospectively ≥ 3 weeks during acute disease and at 3-, 6-, 12-, and 18-months to obtain (para)clinical data and biospecimens. Flow cytometry-based surrogate assay (FlowSA) detected viable SARS-CoV-2. Determinants of long RNA shedding ( ≥ 21 days) were investigated. RNA shedding median duration was 14 days (IQR 8.0-21.0) for nasopharyngeal/throat (NPT) and 7 days (IQR 1.0-27.0) for feces- but 20 days (IQR 7.0-27.8) when excluding individuals positive at a single timepoint (25.2%). Among 17 NPT long shedders with FlowSA results, 12 (70.6%) demonstrated viable virus. NPT long shedding was independently positively associated with endocrine disease and chills. Fecal long shedding was independently inversely associated with age, female sex, and fatigue, but positively with vomiting. No associations with long-term COVID-19-related complaints were observed. Finally, fecal long shedders demonstrated higher anti-spike(S1) IgG levels over 18-month follow-up than non-long shedders (p = 0.006). (Long) SARS-CoV-2 RNA shedding in NPT and feces associates with age and acute-but not prolonged-symptoms. The roles of prolonged infectious shedding and fecal shedding in transmission and immunity remain unclear.

Differences in SARS-CoV-2 antibody prevalence at the end of the pre-vaccination period between age groups: A cross-sectional analysis of the multi-ethnic population-based HELIUS study

BACKGROUND

During the first waves of the COVID-19 pandemic, SARS-CoV-2 antibody prevalence (seroprevalence) was lower in older compared to younger adults. We studied age group differences in SARS-CoV-2 seroprevalence, across ethnic groups, and assessed the explanatory value of factors that increase the exposure to the virus, and factors related to susceptibility, given the level of exposure.

METHODS

We analysed cross-sectional data from 2,064 participants from the multi-ethnic HELIUS study (Amsterdam, The Netherlands). SARS-CoV-2 seroprevalence at the second wave of infections was compared between age groups (<40, 40-54, and ≥55 years), within ethnic groups, using Poisson regression with robust standard errors. To determine whether age group differences were explained by differences in exposure and in susceptibility, we sequentially adjusted for exposure (job setting, occupation level, health literacy, household size, household member with suspected infection), education level, and susceptibility (vitamin D intake, BMI, systolic blood pressure, haemoglobin level, number of comorbidities).

RESULTS

SARS-CoV-2 seroprevalence did not statistically differ across age groups (p>0.05), but age patterns varied across ethnic groups. Age group differences in SARS-CoV-2 seroprevalence were most pronounced in the Dutch majority group, with the highest prevalence ratio in the youngest group (2.55, 95%CI 0.93-6.97) and the lowest in the oldest group (0.53, 95%CI 0.16-1.74), compared to the middle-aged group. In ethnic minority groups, age group differences were smaller. In all groups, patterns did not substantially change after adjustments for exposure and susceptibility variables.

CONCLUSION

We found no evidence of age group differences in SARS-CoV-2 seroprevalence, particularly for ethnic minority groups, even when accounting for exposure and susceptibility. While early prevention strategies particularly aimed at protecting older adults against SARS-CoV-2 infections, seroprevalence was similar across age groups in ethnic minority groups. Thus, older adults in ethnic minority groups may pose a target group for additional prevention strategies for future infectious disease outbreaks.

Effectiveness of COVID-19 Vaccination against Severe Symptoms and Death Among Geriatric Inpatients: A Retrospective Cohort Study in Macao

Monitoring the effectiveness of COVID-19 vaccination is critical for understanding if the vaccinated population, especially the elderly, is adequately protected from the emergence of new SARS-CoV-2 variants. This study aimed to investigate the effects of COVID-19 vaccination on the severity of symptoms and mortality in hospitalized geriatric patients during the Omicron BF.7 surge in Macao. Data from electronic health records and vaccination registry of inpatients aged 60 years or above admitted to Kiang Wu Hospital from 12 December 2022 to 12 March 2023 were retrospectively analyzed. The study involved 848 people, including 426 vaccinated and 422 unvaccinated individuals. The mean CXR scores (8.95 ± 9.49 vs. 11.41 ± 10.81, p < 0.001) and the mean MEWS scores (0.96 ± 2.01 vs. 1.49 ± 2.45, p < 0.001) were lower in the vaccinated group. By comparing the dose counts, no significant difference was seen in the odds of death. Based on the time of the last vaccination, 128 people were categorized as complete and 298 as incomplete vaccination. The complete vaccination group showed a 54% (95% CI 0.23-0.91) reduction in mortality risk (p = 0.026). The study findings not only reconfirm the effectiveness of COVID-19 vaccination but, more importantly, highlight the importance of vaccination timing to maximize vaccines' protective effect.

Age-Related Differences in Neutralizing Antibody Responses against SARS-CoV-2 Delta and Omicron Variants in 151 SARS-CoV-2-Naïve Metropolitan Residents Boosted with BNT162b2

BACKGROUND

Although age negatively correlates with vaccine-induced immune responses, whether the vaccine-induced neutralizing effect against variants of concern (VOCs) substantially differs across age remains relatively poorly explored. In addition, the utility of commercial binding assays developed with the wild-type SARS-CoV-2 for predicting the neutralizing effect against VOCs should be revalidated.

METHODS

We analyzed 151 triple-vaccinated SARS-CoV-2-naïve individuals boosted with BNT162b2 (Pfizer-BioNTech). The study population was divided into young adults (age < 30), middle-aged adults (30 ≤ age < 60), and older adults (age ≥ 60). The plaque reduction neutralization test (PRNT) titers against Delta (B.1.617.2) and Omicron (B.1.1.529) variants were compared across age. Antibody titers measured with commercial binding assays were compared with PRNT titers.

RESULTS

Age-related decline in neutralizing titers was observed for both Delta and Omicron variants. Neutralizing titers for Omicron were lower than those against Delta in all ages. The multiple linear regression model demonstrated that duration from third dose to sample collection and vaccine types were also significant factors affecting vaccine-induced immunity along with age. The correlation between commercial binding assays and PRNT was acceptable for all age groups with the Delta variant, but relatively poor for middle-aged and older adults with the Omicron variant due to low titers.

CONCLUSIONS

This study provides insights into the age-related dynamics of vaccine-induced immunity against SARS-CoV-2 VOCs, corroborating the need for age-specific vaccination strategies in the endemic era where new variants continue to evolve. Moreover, commercial binding assays should be used cautiously when estimating neutralizing titers against VOCs, particularly Omicron.

Cancer Care During the COVID-19 Pandemic: A Retrospective Study From a Najran Oncology Center

Background The COVID-19 pandemic significantly impacted healthcare systems globally, with cancer patients representing a particularly vulnerable group. This study aims to evaluate the influence of COVID-19 on cancer, focusing on infection rates, types of care, therapy adjustments, and factors associated with COVID-19 infection. Materials and methods This single-center retrospective analysis included adult cancer patients who underwent anticancer therapy at King Khalid Hospital in Najran, Saudi Arabia, from December 20, 2020, to January 23, 2022. Data on patient and cancer characteristics, COVID-19 specifics, treatment delays, outcomes, and factors associated with COVID-19 were collected and analyzed. Results A total of 257 chemotherapy recipients were interviewed. The mean age was 52.6 ± 14.4 years, with 44 (17.1%) over 65 years old. Females comprised 160 (62.3%) of the patients. The most common malignancies were gastrointestinal (71, 27.6%), breast (70, 27.2%), and hematological (50, 19.5%). Metastasis was present in 116 patients (45.1%). Common comorbidities included diabetes (68, 26.5%) and hypertension (55, 21.4%). Most patients (226, 87.9%) were vaccinated against COVID-19. COVID-19 tested positive in 22 patients (8.6%), with a lower infection rate in vaccinated patients (7 vs. 15, p < 0.001). Most cases were mild (18, 81.8%), with fever (19, 7.4%) and cough and fatigue (17, 6.6%) being the most common symptoms. The median time to resume treatment post-infection was 30 days. Factors associated with higher infection rates included diabetes (OR: 4.73, 95% CI: 1.94-12.03, p = 0.001), coronary artery disease (OR: 4.13, 95% CI: 1.07-13.30, p = 0.049), chronic lung disease (OR: 15.58, 95% CI: 5.37-45.79, p < 0.001), chronic liver disease (OR: 7.64, 95% CI: 2.38-22.98, p < 0.001), and multiple comorbidities (OR: 2.04, 95% CI: 1.46-2.90, p < 0.001), cancer patients who received chemotherapy (OR: 1.02, 95% CI: 0.12-12.79, p = 0.027), and immunotherapy (OR: 3.37, 95% CI:1.27-8.43, p = 0.012). Conclusion The incidence of COVID-19 in cancer patients is proportional to the prevalence in the general population of similar geographic areas. Diabetes, coronary artery disease, chronic lung disease, chronic liver disease, receiving chemotherapy or immunotherapy, and multiple comorbidities were associated with higher COVID-19 infection rates.

Results of the Cologne Corona Surveillance (CoCoS) project- a cross-sectional study: survey data on risk factors of SARS-CoV-2 infection, and moderate-to-severe course in primarily immunized adults

BACKGROUND

Amidst the COVID-19 pandemic, vaccination has been a crucial strategy for mitigating transmission and disease severity. However, vaccine-effectiveness may be influenced by various factors, including booster vaccination, as well as personal factors such as age, sex, BMI, smoking, and comorbidities. To investigate the potential effects of these factors on SARS-CoV-2 infection and disease severity, we analyzed data from the third round of the Cologne Corona Surveillance (CoCoS) project, a large cross-sectional survey.

METHODS

The study was conducted mid-February to mid-March 2022 in Cologne, Germany. A random sample of 10,000 residents aged 18 years and older were invited to participate in an online survey. Information on participants' demographics (age, sex), SARS-CoV-2 infections, vaccination status, smoking, and preexisting medical conditions were collected. The outcomes of the study were: (1) the occurrence of SARS-CoV-2 infection despite vaccination (breakthrough infection) and (2) the occurrence of moderate-to-severe disease as a result of a breakthrough infection. Cox proportional-hazards regression was used to investigate possible associations between the presence/absence of booster vaccination, personal factors and the occurrence of SARS-CoV-2 infection. Associations with moderate-to-severe infection were analyzed using the Fine and Gray subdistribution hazard model.

RESULTS

A sample of 2,991 residents responded to the questionnaire. A total of 2,623 primary immunized participants were included in the analysis of breakthrough infection and 2,618 in the analysis of SARS-CoV-2 infection severity after exclusions due to incomplete data. The multivariable results show that booster vaccination (HR = 0.613, 95%CI 0.415-0.823) and older age (HR = 0.974, 95%CI 0.966-0.981) were associated with a reduced hazard of breakthrough infection. Regarding the severity of breakthrough infection, older age was associated with a lower risk of moderate-to-severe breakthrough infection (HR = 0.962, 95%CI0.949-0.977). Female sex (HR = 2.570, 95%CI1.435-4.603), smoking (HR = 1.965, 95%CI1.147-3.367) and the presence of chronic lung disease (HR = 2.826, 95%CI1.465-5.450) were associated with an increased hazard of moderate-to-severe breakthrough infection.

CONCLUSION

The results provide a first indication of which factors may be associated with SARS-CoV-2 breakthrough infection and moderate-to-severe course of infection despite vaccination. However, the retrospective nature of the study and risk of bias in the reporting of breakthrough infection severity limit the strength of the results.

TRIAL REGISTRATION

DRKS.de, German Clinical Trials Register (DRKS), Identifier: DRKS00024046, Registered on 25 February 2021.

Nonelective coronary artery bypass graft outcomes are adversely impacted by Coronavirus disease 2019 infection, but not altered processes of care: A National COVID Cohort Collaborative and National Surgery Quality Improvement Program analysis

Objective

The effects of Coronavirus disease 2019 (COVID-19) infection and altered processes of care on nonelective coronary artery bypass grafting (CABG) outcomes remain unknown. We hypothesized that patients with COVID-19 infection would have longer hospital lengths of stay and greater mortality compared with COVID-negative patients, but that these outcomes would not differ between COVID-negative and pre-COVID controls.

Methods

The National COVID Cohort Collaborative 2020-2022 was queried for adult patients undergoing CABG. Patients were divided into COVID-negative, COVID-active, and COVID-convalescent groups. Pre-COVID control patients were drawn from the National Surgical Quality Improvement Program database. Adjusted analysis of the 3 COVID groups was performed via generalized linear models.

Results

A total of 17,293 patients underwent nonelective CABG, including 16,252 COVID-negative, 127 COVID-active, 367 COVID-convalescent, and 2254 pre-COVID patients. Compared to pre-COVID patients, COVID-negative patients had no difference in mortality, whereas COVID-active patients experienced increased mortality. Mortality and pneumonia were higher in COVID-active patients compared to COVID-negative and COVID-convalescent patients. Adjusted analysis demonstrated that COVID-active patients had higher in-hospital mortality, 30- and 90-day mortality, and pneumonia compared to COVID-negative patients. COVID-convalescent patients had a shorter length of stay but a higher rate of renal impairment.

Conclusions

Traditional care processes were altered during the COVID-19 pandemic. Our data show that nonelective CABG in patients with active COVID-19 is associated with significantly increased rates of mortality and pneumonia. The equivalent mortality in COVID-negative and pre-COVID patients suggests that pandemic-associated changes in processes of care did not impact CABG outcomes. Additional research into optimal timing of CABG after COVID infection is warranted.

Key risk factors associated with fractal dimension based geographical clustering of COVID-19 data in the Flemish and Brussels region, Belgium

Introduction

COVID-19 remains a major concern globally. Therefore, it is important to evaluate COVID-19's rapidly changing trends. The fractal dimension has been proposed as a viable method to characterize COVID-19 curves since epidemic data is often subject to considerable heterogeneity. In this study, we aim to investigate the association between various socio-demographic factors and the complexity of the COVID-19 curve as quantified through its fractal dimension.

Methods

We collected population indicators data (ethnic composition, socioeconomic status, number of inhabitants, population density, the older adult population proportion, vaccination rate, satisfaction, and trust in the government) at the level of the statistical sector in Belgium. We compared these data with fractal dimension indicators of COVID-19 incidence between 1 January - 31 December 2021 using canonical correlation analysis.

Results

Our results showed that these population indicators have a significant association with COVID-19 incidences, with the highest explanatory and predictive power coming from the number of inhabitants, population density, and ethnic composition.

Conclusion

It is important to monitor these population indicators during a pandemic, especially when dealing with targeted interventions for a specific population.

Antibody response to inactivated COVID-19 vaccine in patients with type 2 diabetes mellitus after the booster immunization

BACKGROUND

The immunogenicity of booster inactivated COVID-19 vaccines in patients with type 2 diabetes mellitus (T2DM) has remained unclear. Our study aims to investigate the antibody response to inactivated COVID-19 vaccine following booster vaccination in patients with T2DM.

METHODS

A total of 201 patients with T2DM and 102 healthy controls (HCs) were enrolled. The levels of anti-SARS-CoV-2 total antibodies, anti-receptor-binding domain (RBD)-specific IgG, neutralizing antibody (NAb) toward SARS-CoV-2 wild type (WT), and NAb toward SARS-CoV-2 Omicron BA.4/5 subvariant were measured to evaluate the vaccine-induced immunological responses.

RESULTS

The titers of anti-RBD-specific IgG (p = 0.018) and inhibition rates of NAb toward WT (p = 0.007) were significantly decreased in patients with T2DM compared to HCs after booster vaccination for more than 6 months. Both HCs and patients with T2DM showed poor resistance against BA.4/5 due to the detected inhibition rates being lower than the positive threshold. The levels of anti-RBD-specific IgG were positively associated with the proportions of CD3+ CD4- CD8- T cells (p = 0.045), and patients with T2DM who had anti-RBD-specific IgG positivity showed higher proportions of CD3+ CD4- CD8- T cells compared to those negative (p = 0.005).

CONCLUSIONS

Patients with T2DM showed impaired antibody responses after booster vaccination for more than 6 months. Decreased anti-BA.4/5 responses give rise to the possibility of breakthrough infections for both patients with T2DM and HCs.

Rationale for combined therapies in severe-to-critical COVID-19 patients

An unprecedented global social and economic impact as well as a significant number of fatalities have been brought on by the coronavirus disease 2019 (COVID-19), produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute SARS-CoV-2 infection can, in certain situations, cause immunological abnormalities, leading to an anomalous innate and adaptive immune response. While most patients only experience mild symptoms and recover without the need for mechanical ventilation, a substantial percentage of those who are affected develop severe respiratory illness, which can be fatal. The absence of effective therapies when disease progresses to a very severe condition coupled with the incomplete understanding of COVID-19's pathogenesis triggers the need to develop innovative therapeutic approaches for patients at high risk of mortality. As a result, we investigate the potential contribution of promising combinatorial cell therapy to prevent death in critical patients.

Humoral and Cellular Immune Response Elicited by the BNT162b2 COVID-19 Vaccine Booster in Elderly

Although the safety and efficacy of COVID-19 vaccines in older people are critical to their success, little is known about their immunogenicity among elderly residents of long-term care facilities (LTCFs). A single-center prospective cohort study was conducted: a total IgG antibody titer, neutralizing antibodies against Wild-type, Delta Plus, and Omicron BA.2 variants and T cell response, were measured eight months after the second dose of BNT162b2 vaccine (T0) and at least 15 days after the booster (T1). Forty-nine LTCF residents, with a median age of 84.8 ± 10.6 years, were enrolled. Previous COVID-19 infection was documented in 42.9% of the subjects one year before T0. At T1, the IgG titers increased up to 10-fold. This ratio was lower in the subjects with previous COVID-19 infection. At T1, IgG levels were similar in both groups. The neutralizing activity against Omicron BA.2 was significantly lower (65%) than that measured against Wild-type and Delta Plus (90%). A significant increase of T cell-specific immune response was observed after the booster. Frailty, older age, sex, cognitive impairment, and comorbidities did not affect antibody titers or T cell response. In the elderly sample analyzed, the BNT162b2 mRNA COVID-19 vaccine produced immunogenicity regardless of frailty.

The immune mechanism of the nasal epithelium in COVID-19-related olfactory dysfunction

During the first waves of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, olfactory dysfunction (OD) was reported as a frequent clinical sign. The nasal epithelium is one of the front-line protections against viral infections, and the immune responses of the nasal mucosa may be associated with OD. Two mechanisms underlying OD occurrence in COVID-19 have been proposed: the infection of sustentacular cells and the inflammatory reaction of the nasal epithelium. The former triggers OD and the latter likely prolongs OD. These two alternative mechanisms may act in parallel; the infection of sustentacular cells is more important for OD occurrence because sustentacular cells are more likely to be the entry point of SARS-CoV-2 than olfactory neurons and more susceptible to early injury. Furthermore, sustentacular cells abundantly express transmembrane protease, serine 2 (TMPRSS2) and play a major role in the olfactory epithelium. OD occurrence in COVID-19 has revealed crucial roles of sustentacular cells. This review aims to elucidate how immune responses of the nasal epithelium contribute to COVID-19-related OD. Understanding the underlying immune mechanisms of the nasal epithelium in OD may aid in the development of improved medical treatments for COVID-19-related OD.

Aging During the Pandemic: Untangling the Complexities of COVID-19 and Geriatric Care

The COVID-19 pandemic has posed unprecedented challenges to the global healthcare system, with the elderly population being particularly vulnerable. This comprehensive review synthesizes the findings from publications in "Aging and Disease", highlighting the unique challenges older adults encountered during the pandemic and providing solutions thereof. These studies provide invaluable insights into the elderly population's vulnerabilities and needs during the COVID-19 pandemic. The susceptibility to the virus in older individuals remains debatable, and research on the clinical picture of COVID-19 in older populations has yielded insights into clinical features, molecular mechanisms, and potential therapeutic strategies. This review intends to shed light on the need of sustaining physical and mental well-being among older adults during the periods of lockdown by extensively exploring these concerns and emphasizing the need for targeted interventions and support systems for this population. Ultimately, the findings of these studies contribute to developing more effective and comprehensive approaches to managing and mitigating the risks posed by the pandemic to the elderly.