Informing the public health response to COVID-19: a systematic review of risk factors for disease, severity, and mortality

Surveillance of SARS-CoV-2 variants in Henan, China from 2023 to 2024

Objective

In January 2023, China implemented the "Class B Management" policy, marking a new phase in COVID-19 control. As new SARS-CoV-2 variants continue to emerge, some have shown significant immune evasion, posing challenges to epidemic control efforts. To manage the pandemic effectively, Henan Province launched a surveillance program for SARS-CoV-2 variants, systematically analyzing their clinical characteristics and epidemiological patterns.

Methods

This study collected genomic sequence data from 5,965 COVID-19 cases between January 1, 2023, and March 17, 2024, using the Henan Province SARS-CoV-2 variant surveillance system. Genome sequence analysis was performed with CLC Genomics Workbench, and genotyping and sequence alignment were carried out using the Nextclade platform. The clinical severity of different variants was assessed in relation to patient sex, age, clinical classification, and vaccination status.

Results

Between Week 1 of 2023 and Week 11 of 2024, a total of 5,965 complete SARS-CoV-2 genome sequences were obtained, including 3,004 male (50.36%) and 2,961 female (49.64%) cases. The majority of cases were mild (5,451 cases, 91.38%), followed by moderate (311 cases, 5.21%) and severe or critical cases (203 cases, 3.4%). The predominant variants included BA.5.2, XBB, and BA.2.86. BA.5.2 was dominant until April 2023, after which it was gradually replaced by XBB. From December 2023, BA.2.86 began to increase and became the predominant variant by January 2024. The XBB variant exhibited a significantly lower rate of severe cases, with most infections being mild (P < 0.05). Male patients, the elderly, and certain variants (e.g., BA.5.2) were associated with more severe outcomes, while XBB and BA.2.86 showed lower pathogenicity, with a marked reduction in severe and fatal cases (P < 0.05).

Conclusion

As SARS-CoV-2 variants evolve, the incidence of severe cases has progressively decreased. Both XBB and BA.2.86 variants exhibit lower pathogenicity. This study provides vital scientific evidence on the epidemiological features, clinical manifestations, and control strategies of SARS-CoV-2 variants. It underscores the importance of continuous viral surveillance and genomic sequencing to guide public health decision-making.

Factors of progression to severity and death in COVID-19 patients at two health care sites in Bamako, Mali

OBJECTIVES

To analyze the clinical and biological characteristics and to evaluate the risk factors associated with the mortality of patients with COVID-19 in Commune IV of the District of Bamako.

METHODS

The cohort consisted of COVID-19 patients managed from March 2020 to June 2022 at the Bamako Dermatology Hospital and the Pasteur Polyclinic in Commune IV in Bamako. The studied variables were sociodemographic, clinical, and biological. For the analysis of deaths, explanatory variables were grouped into sociodemographic factors, comorbidities and symptoms. Binomial logistic regression models were used to identify mortality associated risk factors.

RESULTS

Among the 1319 included patients, 38.4% were asymptomatic, 46% and 15.5% developed moderate or severe COVID-19 respectively. The predominant signs were cough (48.5%), respiratory difficulty (24.6%) and headache (19.7%). Male were more common (58.2%). High blood pressure (19.9%) and diabetes (10%) were the main comorbidities. D-dimers < 0.5 μg/l was found in 53.3% of cases and the mean hemoglobin level was 12.9 ± 1.7 g/l. The case fatality rate was 3.71% in our series. In bivariate analysis, age > 60 years, high blood pressure, diabetes, clinical severity, D-dimers < 0.5 μg/l were associated with death. Using binomial logistic regression method, age > 60 years, increased heart rate, disease severity level and mainly acute respiratory distress syndrome (polypnea, difficulty breathing) were the factors found associated with death. After adjusting for all the assessed factors, age < 60 years [aHR = 0.15 (0.06-0.35)] and administration of azithromycin [aHR = 0.31 (0.1-0.97)] were protective factors while higher respiratory rate [aHR = 1.14 (1.07-1.22)] and difficulty breathing [aHR = 3.06 (1.03-9.13)] were risk factors associated with death.

CONCLUSION

These main findings elucidate the factors associated with severity and lethality external of health care system constraints. Advanced age, higher heart rate and the development of respiratory distress were the factors significantly associated with increased fatalities.

Latent Class Analysis Reveals, in patient profiles, COVID-19-related better prognosis by calcifediol treatment than glucocorticoids

Calcifediol and glucocorticoids have been repositioned for the treatment of COVID-19 and may reduce severity, the need for intensive care unit admission and death.

OBJECTIVE

to identify class or profiles of patients hospitalized and treated with COVID-19 pneumonia using latent class clustering methods to assess the clinical and prognostic relevance of the resulting patients' profiles. Poor prognosis was defined as death or need for ICU admission, good prognosis, the opposite. With special interest in differential responses to calcifediol.

SETTING

Reina Sofia University Hospital, Córdoba Spain.

PATIENTS

Retrospective observational cohort study of patients admitted for COVID-19.

CLINICALTRIALS

gov public database (NCT05819918).

INCLUSION CRITERIA

(i) Age ≥ 18 and ≤ 90 years, (ii) Pneumonia characterized by the presence of infiltrates on chest X-ray or CT scan, (iii) SARS-CoV-2 infection, confirmed, and (iv) CURB Scale 65 >1.

DESIGN

Latent class analysis, for obtaining homogeneous clusters, without specifying a priori the belonging group, and selecting the optimal number of clusters by minimizing information criteria. Evaluating the differences between groups for each variable by means of chi-square, Fisher's exact test and Kruskal-Wallis test.

RESULTS

707 patients hospitalized from 10 March 2020 until 4 March 2022 were included. For the treatment variable, differences were found between class 3 (60 % treated with calcifediol only) and classes 1 (less than 1 % calcifediol only vs. 82 % treated with both), 2 (less than 1 % calcifediol only vs. 82 % treated with both) and 4 (1 % calcifediol only vs. 84 % treated with both). Class 3, (60 % with calcifediol), had a significantly better prognosis compared to patients treated with glucocorticoids alone (OR: 15.2, 95 % CI: [3.73-142], p<0.001) or no treatment (OR: 7.38, 95 % CI: [2.63-30.2], p<0.001).

CONCLUSIONS

our real-life study shows that calcifediol treatment significantly reduces the need for ICU admission and improved prognosis in patients hospitalized for COVID-19 pneumonia, especially in the profile of patients receiving it without glucocorticoids.

Enhancing COVID-19 booster vaccination among the elderly through text message reminders

The BOOST (Booster promotion for older outpatients using SMS text reminders) program at Taipei Veterans General Hospital assessed the effectiveness of text message reminders in enhancing COVID-19 booster vaccination rates among the elderly, guided by the Health Belief Model (HBM). Targeting patients aged 65 and above, eligible yet unvaccinated for a COVID-19 booster, this cohort study sent personalized reminders a week prior to their scheduled appointments between April 18, 2022, and May 12, 2022, acting as cues to action to enhance vaccination uptake by overcoming perceived barriers and raising awareness of benefits. Over 5 weeks, the study observed a 38% increase in vaccination rate among 3,500 eligible patients, markedly surpassing the concurrent national rate increase of 4% for the same demographic. The majority of vaccinations occurred within two weeks after the reminder, illustrating the effectiveness of the strategy. Cox regression analysis identified age and time since last vaccination as significant predictors of responsiveness, with those aged 65-74 and 75-84 showing higher uptake, particularly when reminders were sent within 4 months after the last dose. A single reminder proved to be effective. The findings of this study demonstrate the potential of SMS reminders to promote COVID-19 vaccination among the elderly through the strategic use of HBM principles, suggesting a feasible and effective approach to public health communication.

SARS-CoV-2 Infection Risk by Vaccine Doses and Prior Infections Over 24 Months: ProHEpiC-19 Longitudinal Study

Background

As the vaccination campaign against COVID-19 progresses, it becomes crucial to comprehend the lasting effects of vaccination on safeguarding against new infections or reinfections.

Objective

This study aimed to assess the risk of new SARS-CoV-2 infections based on the number of vaccine doses, prior infections, and other clinical characteristics.

Methods

We defined a cohort of 800 health care workers in a 24-month study (March 2020 to December 2022) in northern Barcelona to determine new infections by SARS-CoV-2. We used extended Cox models, specifically Andersen-Gill (AG) and Prentice-Williams-Peterson, and we examined the risk of new infections. The AG model incorporated variables such as sex, age, job title, number of chronic conditions, vaccine doses, and prior infections. Additionally, 2 Prentice-Williams-Peterson models were adjusted, one for those individuals with no or 1 infection and another for those with 2 or 3 infections, both with the same covariates as the AG model.

Results

The 800 participants (n=605, 75.6% women) received 1, 2, 3, and 4 doses of the vaccine. Compared to those who were unvaccinated, the number of vaccine doses significantly reduced (P<.001) the risk of infection by 66%, 81%, 89%, and 99%, respectively. Unit increase in the number of prior infections reduced the risk of infection by 75% (P<.001). When separating individuals by number of previous infections, risk was significantly reduced for those with no or 1 infection by 61% (P=.02), and by 88%, 93%, and 99% (P<.001) with 1, 2, 3, or 4 doses, respectively. In contrast, for those with 2 or 3 previous infections, the reduction was only significant with the fourth dose, at 98% (P<.001). The number of chronic diseases only increased the risk by 28%-31% (P<.001) for individuals with 0-1 previous infections.

Conclusions

The study suggests that both prior infections and vaccination status significantly contribute to SARS-CoV-2 immunity, supporting vaccine effectiveness in reducing risk of reinfection for up to 24 months after follow-up from the onset of the pandemic. These insights contribute to our understanding of long-term immunity dynamics and inform strategies for mitigating the impact of COVID-19.

Protecting effects of smoking against COVID-19: a community-based retrospective cohort study in middle- and older-aged adults

On December 7, 2022, China switched from dynamic zeroing strategy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to reopening. A nationwide SARS-CoV-2 epidemic emerged rapidly. The effect of smoking on SARS-CoV-2 infection remains unclear. We aimed to retrospectively investigate the relationship between smoking and coronavirus disease 2019 (COVID-19) using a community-based cohort of smokers and non-smokers. We included participants from a pre-pandemic cohort with a prolonged follow-up period. Data on smoking status, body mass index, and history of other diseases were collected from health examination and consultation clinic records. Cox regression analysis was used to identify the relationship between groups and SARS-CoV-2 infection over time. We analysed 218 male patients with varied smoking statuses (46.3% current or ex-smokers; average age 68.63 ± 9.81 years). Two peaks in the epidemic were observed following the December 2022 outbreak. At the end of the second peak, non-smokers, current smokers, and ex-smokers had primary infection rates increase to 88.0%, 65.1%, and 81.0%, respectively, with a significant difference between the groups. Current smoking significantly protected against SARS-CoV-2 infection (HR 0.625, 95% CI 0.402-0.970, p = 0.036). Further analyses showed that the prevalence of pneumonia in the unvaccinated, older, diabetic, and non-smoking groups was significantly higher than that in the other groups (p < 0.05). Our study suggests a potential association between smoking and a reduced risk of SARS-CoV-2 infection and pneumonia. This indicates that nicotine and ACE2 play important roles in preventing COVID-19 and its progression. We suggest smokers use nicotine replacement therapy during hospitalization for COVID-19.

Clinical Characteristics, Prognostic Factors, and Outcomes of COVID-19 in Autoimmune Rheumatic Disease Patients: A Retrospective Case-Control Study from Astana, Kazakhstan

Background: Viral infections, including coronavirus disease 2019 (COVID-19), in patients with autoimmune rheumatic diseases (AIRDs) tend to present more severe disease. This study aims to investigate the clinical characteristics and risk factors for severe infection in rheumatologic patients. Methods: We included patients with a diagnosis of AIRD and COVID-19 infection between January 2022 and July 2023. Patients with AIRDs infected with SARS-CoV-2 were matched with control patients of the general population according to age (±5 years) and sex in a 1:1 ratio. Confirmed infection was defined if a patient had a positive polymerase chain reaction (PCR) test. The severity was divided into mild, moderate, severe, and critical according to the guidelines of the United States National Institutes of Health (NIH). Results: A total of 140 individuals (37 males, 103 females; mean age 56.1 ± 11.3 years) with rheumatic disease diagnosed with COVID-19 infection were enrolled in the study. AIRDs included rheumatoid arthritis (RA) (n = 63, 45%), ankylosing spondylitis (AS) (n = 35, 25%), systemic lupus erythematosus (SLE) (n = 26, 8.6%), and systemic sclerosis (SSc) (n = 16, 11.4%). The AIRDs group had more SARS-CoV-2-related dyspnea (38.6%), arthralgia (45.7%), and depression (27.1%) than the control group (p = 0.004). The rate of lung infiltration on radiographic examination was higher in 58 (41.4%, p = 0.005) patients with rheumatic diseases than in those without them. Severe SARS-CoV-2 infection was more common in the AIRDs group than in the control group (22% vs. 12%; p = 0.043). Conclusions: Patients with AIRDs experienced more symptoms of arthralgia, depression, and dyspnea. There was a trend towards an increased severity of the disease in patients with AIRDs. Patients with arterial hypertension, diabetes, chronic lung, and kidney disease, treated with corticosteroids, had a longer duration, and high activity of autoimmune disease had an increased risk of severe COVID-19.

Natural and socio-environmental factors in the transmission of COVID-19: a comprehensive analysis of epidemiology and mechanisms

PURPOSE OF REVIEW

There are significant differences in the transmission rate and mortality rate of COVID-19 under environmental conditions such as seasons and climates. However, the impact of environmental factors on the role of the COVID-19 pandemic and the transmission mechanism of the SARS-CoV-2 is unclear. Therefore, a comprehensive understanding of the impact of environmental factors on COVID-19 can provide innovative insights for global epidemic prevention and control policies and COVID-19 related research. This review summarizes the evidence of the impact of different natural and social environmental factors on the transmission of COVID-19 through a comprehensive analysis of epidemiology and mechanism research. This will provide innovative inspiration for global epidemic prevention and control policies and provide reference for similar infectious diseases that may emerge in the future.

RECENT FINDINGS

Evidence reveals mechanisms by which natural environmental factors influence the transmission of COVID-19, including (i) virus survival and transport, (ii) immune system damage, (iii) inflammation, oxidative stress, and cell death, and (iiii) increasing risk of complications. All of these measures appear to be effective in controlling the spread or mortality of COVID-19: (1) reducing air pollution levels, (2) rational use of ozone disinfection and medical ozone therapy, (3) rational exposure to sunlight, (4) scientific ventilation and maintenance of indoor temperature and humidity, (5) control of population density, and (6) control of population movement. Our review indicates that with the continuous mutation of SARS-CoV-2, high temperature, high humidity, low air pollution levels, and low population density more likely to slow down the spread of the virus.

COVID-19 infections in English schools and the households of students and staff 2020-21: a self-controlled case-series analysis

BACKGROUND

The role of children and staff in SARS-CoV-2 transmission outside and within households is still not fully understood when large numbers are in regular, frequent contact in schools.

METHODS

We used the self-controlled case-series method during the alpha- and delta-dominant periods to explore the incidence of infection in periods around a household member infection, relative to periods without household infection, in a cohort of primary and secondary English schoolchildren and staff from November 2020 to July 2021.

RESULTS

We found the relative incidence of infection in students and staff was highest in the 1-7 days following household infection, remaining high up to 14 days after, with risk also elevated in the 6--12 days before household infection. Younger students had a higher relative incidence following household infection, suggesting household transmission may play a more prominent role compared with older students. The relative incidence was also higher among students in the alpha variant dominant period.

CONCLUSIONS

This analysis suggests SARS-CoV2 infection in children, young people and staff at English schools were more likely to be associated with within-household transmission than from outside the household, but that a small increased risk of seeding from outside is observed.

Age-specific transmission dynamics of SARS-CoV-2 during the first 2 years of the pandemic

During its first 2 years, the SARS-CoV-2 pandemic manifested as multiple waves shaped by complex interactions between variants of concern, non-pharmaceutical interventions, and the immunological landscape of the population. Understanding how the age-specific epidemiology of SARS-CoV-2 has evolved throughout the pandemic is crucial for informing policy decisions. In this article, we aimed to develop an inference-based modeling approach to reconstruct the burden of true infections and hospital admissions in children, adolescents, and adults over the seven waves of four variants (wild-type, Alpha, Delta, and Omicron BA.1) during the first 2 years of the pandemic, using the Netherlands as the motivating example. We find that reported cases are a considerable underestimate and a generally poor predictor of true infection burden, especially because case reporting differs by age. The contribution of children and adolescents to total infection and hospitalization burden increased with successive variants and was largest during the Omicron BA.1 period. However, the ratio of hospitalizations to infections decreased with each subsequent variant in all age categories. Before the Delta period, almost all infections were primary infections occurring in naive individuals. During the Delta and Omicron BA.1 periods, primary infections were common in children but relatively rare in adults who experienced either reinfections or breakthrough infections. Our approach can be used to understand age-specific epidemiology through successive waves in other countries where random community surveys uncovering true SARS-CoV-2 dynamics are absent but basic surveillance and statistics data are available.

SARS-CoV-2 vaccines in China could reduce COVID-19-related respiratory syndromes and deaths: A retrospective cohort study

Background

Information is limited regarding the effectiveness of the inactivated vaccine for COVID-19 approved in China in preventing infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) when administered in real-world conditions.

Methods

We retrospectively surveyed 1352 patients with a positive SARS-CoV-2 nucleic acid test treated at a major tertiary medical center in Foshan city (Guangdong, China) between November 2022 and February 2023. The exposure group was patients who had previously received the COVID-19 vaccine, which included patients who had received different doses of the vaccine and different vaccine types. The primary outcome of this study was the effectiveness of the vaccine in preventing severe disease and death among SARS-CoV-2-infected patients.

Results

We found a mortality rate of 12.1 % associated with COVID-19. The results showed that an increase in the number of vaccine doses was associated with a reduction in in-hospital mortality. When compared to unvaccinated patients, vaccinated patients had an 8.5 % lower mortality rate. There was also a statistically significant reduction in the risk of death among vaccinated patients compared to unvaccinated patients (OR = 0.521 [95 % CI, 0.366 to 0.741]). Patients who had received the vaccine had a 22.8 % reduction in the risk of severe disease. In addition, the use of antiviral drugs decreased progressively with increasing vaccine doses (P < 0.05). Of these, anticoagulation, Paxlovid, and mechanical ventilation were used least frequently in the one-dose group.

Conclusions

The vaccines approved in China mitigated the incidence of severe COVID-19 and reduced mortality. These findings suggest that COVID-19 vaccination can help to control the pandemic.

The Epidemiological Analysis of COVID-19 Outbreaks in Nursing Homes during the Period of Omicron Variant Predominance

BACKGROUND

The main purpose of this study was to evaluate the epidemic trend and risk factors associated with COVID-19 outbreaks in nursing homes during the period of Omicron variant predominance.

METHODS

The study analyzed the risk factors associated with SARS-CoV-2 infection and death among the 327 residents and 129 healthcare workers (HCWs) in three hospital-affiliated nursing homes through a multivariate Cox regression model.

RESULTS

The rates of receiving a COVID-19 booster dose were 70.3% for the residents and 93.0% for the healthcare workers (HCWs), respectively. A number of asymptomatic individuals, including 54 (16.5%) residents and 15 (11.6%) HCWs, were detected through mass screening surveillance tests. The COVID-19 infection rates during the outbreaks were 41.6% among residents and 48.1% among HCWs, respectively. The case fatality rate among residents was 10.3%. None of the HCWs were hospitalized or died. The multivariate Cox regression model showed that the risk of COVID-19 infection increased in males (HR 2.46; 95% CI 1.47-4.11; p = 0.001), Barthel index ≥ 61 (HR 1.93; 95% CI 1.18-3.17; p = 0.009), and dementia (HR 1.61; 95% CI 1.14-2.27; p = 0.007). The risk of COVID-19 death increased with pneumonia (HR 11.03; 95% CI 3.02-40.31; p < 0.001), hospitalization (HR 7.18; 95% CI 1.97-26.25; p = 0.003), and admission to an intensive care unit (HR 8.67; 95% CI 2.79-26.89; p < 0.001).

CONCLUSIONS

This study highlighted the high infection rates with a substantial proportion of asymptomatic infections for both residents and HCWs, as well as a high case fatality rate for the residents among nursing homes during the Omicron epidemic period. We suggest implementing mass screening through regular surveillance testing as an effective strategy for early detection of COVID-19 and for preventing transmission during an epidemic period. Pneumonia is the primary risk associated with COVID-19 death. Early detection and prompt treatment of pneumonia for vulnerable residents in nursing homes are crucial to protect them from potential mortality.

Differences in the severity and mortality risk factors for patients hospitalized for COVID-19 pneumonia between the early wave and the very late stage of the pandemic

Background

Since China's dynamic zero-COVID policy is cancelled on December 7, 2022, the rapidly growing number of patients has brought a major public health challenge. This study aimed to assess whether there were differences in the severity and mortality risk factors for patients hospitalized for COVID-19 pneumonia between the early wave and the very late stage of the pandemic.

Methods

A retrospective cross-sectional study was carried out using data from 223 hospitalized patients diagnosed with COVID-19 pneumonia during the Omicron surge in Xi'an People's Hospital (Xi'an Fourth Hospital) from December 8, 2022, to January 31, 2023. Univariable and multivariable logistic regression analyses were used to identify potential risk factors associated with the severity and mortality of COVID-19 pneumonia during the first wave of the pandemic after the dynamic zero-COVID policy was retracted. Differences in the severity and mortality risk factors were assessed at different stages of the pandemic, mainly from demographic, clinical manifestation, laboratory tests and radiological findings of patients on admission.

Results

The mean age of the 223 participants was 71.2 ± 17.4. Compared with the patients in the initial stage of the pandemic, the most common manifestation among patients in this study was cough (90.6%), rather than fever (79.4%). Different from the initial stage of the pandemic, older age, chest tightness, elevated neutrophil-to-lymphocyte ratio (NLR), decreased albumin (ALB) level and ground glass opacification (GGO) in radiological finding were identified as severity risk factors, instead of mortality risk factors for COVID-19 patients in the very late stage of the pandemic. Arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ≤300 mmHg, cardiovascular disease and laboratory findings including elevated levels of D-dimer, α-hydroxybutyrate dehydrogenase (α-HBDH), total bilirubin (TBIL), alanine aminotransferase (ALT), urea nitrogen (BUN), creatinine (CR), fasting blood glucose (FBG) and decreased platelet count (PLT) were still associated with mortality in the very late stage of the pandemic.

Conclusion

Monitoring continuously differences in the severity and mortality risk factors for COVID-19 patients between different stages of the pandemic could provide evidence for exploring uncharted territory in the coming post-pandemic era.

Efficacy and Safety of Vaccinations in Geriatric Patients: A Literature Review

With the progressive lengthening of the average age of the population, especially in some countries such as Italy, vaccination of the elderly is a fixed point on which most of the public health efforts are concentrating as epidemic infectious diseases, especially those of the winter, have a major impact on the progression of severe disease, hospitalization, and death. The protection of the elderly against acute infectious diseases should not only limit mortality but also have a positive impact on the fragility of these people in terms of less disability and fewer care needs. However, vaccination of the elderly population differs in efficacy and safety compared to that of other population categories since aging and the consequent loss of efficiency of the immune system lead to a reduction in the immunogenicity of vaccines without achieving a lasting antibody coverage. There are various strategies to avoid the failure of immunization by vaccines such as resorting to supplementary doses with adjuvant vaccines, increasing the dosage of the antigen used, or choosing to inoculate the serum relying on various routes of administration of the vaccine. Vaccination in the elderly is also an important factor in light of growing antibiotic resistance because it can indirectly contribute to combating antibiotic resistance, reducing theoretically the use of those agents. Furthermore, vaccination in old age reduces mortality from infectious diseases preventable with vaccines and reduces the same rate of resistance to antibiotics. Given the importance and complexity of the topic, in this review, we will deal with the main aspects of vaccination in the elderly and how it can influence mortality and healthcare costs, especially in those countries where population aging is more evident. Therefore, we conducted a systematic literature search in PubMed to identify all types of studies published up to 31 May 2023 that examined the association between vaccination and the elderly. Data extraction and quality assessment were conducted by two reviewers (PC and TC) who independently extracted the following data and assessed the quality of each study.

Evolutionary implications of SARS-CoV-2 vaccination for the future design of vaccination strategies

Once the first SARS-CoV-2 vaccine became available, mass vaccination was the main pillar of the public health response to the COVID-19 pandemic. It was very effective in reducing hospitalizations and deaths. Here, we discuss the possibility that mass vaccination might accelerate SARS-CoV-2 evolution in antibody-binding regions compared to natural infection at the population level. Using the evidence of strong genetic variation in antibody-binding regions and taking advantage of the similarity between the envelope proteins of SARS-CoV-2 and influenza, we assume that immune selection pressure acting on these regions of the two viruses is similar. We discuss the consequences of this assumption for SARS-CoV-2 evolution in light of mathematical models developed previously for influenza. We further outline the implications of this phenomenon, if our assumptions are confirmed, for the future design of SARS-CoV-2 vaccination strategies.

Factors Associated with COVID-19 Death in a High-Altitude Peruvian Setting during the First 14 Months of the Pandemic: A Retrospective Multicenter Cohort Study in Hospitalized Patients

Risk factors for COVID-19 death in high-altitude populations have been scarcely described. This study aimed to describe risk factors for COVID-19 death in three referral hospitals located at 3399 m in Cusco, Peru, during the first 14 months of the pandemic. A retrospective multicenter cohort study was conducted. A random sample of ~50% (1225/2674) of adult hospitalized patients who died between 1 March 2020 and 30 June 2021 was identified. Of those, 977 individuals met the definition of death by COVID-19. Demographic characteristics, intensive care unit (ICU) admission, invasive respiratory support (IRS), disease severity, comorbidities, and clinical manifestation at hospital admission were assessed as risk factors using Cox proportional-hazard models. In multivariable models adjusted by age, sex, and pandemic periods, critical disease (vs. moderate) was associated with a greater risk of death (aHR: 1.27; 95%CI: 1.14-1.142), whereas ICU admission (aHR: 0.39; 95%CI: 0.27-0.56), IRS (aHR: 0.37; 95%CI: 0.26-0.54), the ratio of oxygen saturation (ROX) index ≥ 5.3 (aHR: 0.87; 95%CI: 0.80-0.94), and the ratio of SatO2/FiO2 ≥ 122.6 (aHR: 0.96; 95%CI: 0.93-0.98) were associated with a lower risk of death. The risk factors described here may be useful in assisting decision making and resource allocation.

Risk and Protective Factors for COVID-19 Morbidity, Severity, and Mortality

The outbreak of the coronavirus disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become an evolving global health crisis. Currently, a number of risk factors have been identified to have a potential impact on increasing the morbidity of COVID-19 in adults, including old age, male sex, pre-existing comorbidities, and racial/ethnic disparities. In addition to these factors, changes in laboratory indices and pro-inflammatory cytokines, as well as possible complications, could indicate the progression of COVID-19 into a severe and critical stage. Children predominantly suffer from mild illnesses due to COVID-19. Similar to adults, the main risk factors in pediatric patients include age and pre-existing comorbidities. In contrast, supplementation with a healthy diet and sufficient nutrition, COVID-19 vaccination, and atopic conditions may act as protective factors against the infection of SARS-CoV-2. COVID-19 vaccination not only protects vulnerable individuals from SARS-CoV-2 infection, more importantly, it may also reduce the development of severe disease and death due to COVID-19. Currently used therapies for COVID-19 are off-label and empiric, and their impacts on the severity and mortality of COVID-19 are still unclear. The interaction between asthma and COVID-19 may be bidirectional and needs to be clarified in more studies. In this review, we highlight the clinical evidence supporting the rationale for the risk and protective factors for the morbidity, severity, and mortality of COVID-19.

Factors associated with covid-19 deaths in the city of Recife, Pernambuco, Brazil, 2020: a cross-sectional study with "Notifique Aqui" system data

OBJECTIVE

to analyze the clinical conditions and sociodemographic characteristics associated with covid-19 deaths in the first year of the pandemic in the city of Recife, Pernambuco, Brazil, 2020.

METHODS

this was a cross-sectional study with covid-19-induced severe acute respiratory syndrome cases recorded in 2020 via the "Notifique Aqui" (Report Here) electronic system of the Pernambuco Center for Strategic Information on Health Surveillance. Association between death and sociodemographic and clinical variables was analyzed. Prevalence ratios (PR) with 95% confidence intervals (95%CI) were calculated using adjusted Poisson regression.

RESULTS

the prevalence of death was 28.4% (2,833 cases; 95%CI 27.51;29.28). The associated factors were male sex (PR = 1.05; 95%CI 1.01;1.08), age ≥ 60 years (PR = 0.76; 95%CI 0.72;0.79), dyspnea (PR = 1.06; 95%CI 1.02;1.10), respiratory distress (PR = 1.06; 95%CI 1.03;1.09), oxygen saturation < 95% (PR = 1.08; 95%CI 1.04;1.11) and chronic diseases.

CONCLUSION

covid-19 deaths were more prevalent among male, older adults, and people with pre-existing health problems, these being priority groups for combating the pandemic.

Ready for Vaccination? COVID-19 Vaccination Willingness of Older People in Austria

In spite of findings highlighting higher health risk from infection compared to younger people, a certain percentage of older people in Austria still lack a valid vaccination certificate. The current gaps in vaccination coverage in countries such as Austria are likely to be in large part due to vaccination refusal and pose or will pose problems for the health system and consequently for all of society should the initial findings on Omicron coronavirus infectivity prove true. Surprisingly, only a few studies around the globe explicitly address older people's COVID-19 vaccination willingness. The present work therefore intends to contribute to this field by identifying factors associated with the decision for or against a vaccination among the older population in Austria. Data collected between late 2020 and early 2021 via the cross-national panel study Survey of Health, Aging and Retirement in Europe (SHARE) are used to perform multinomial logistic regression to analyse differences between COVID-19 vaccination supporters, undecided persons and rejectors. The results show that persons exhibiting a low risk assessment toward COVID-19, less health protection behaviors, lower education and belonging to households with financial burdens are significantly more likely to refuse vaccination or be ambivalent. Although multimorbidity reduces risk of vaccination refusal, poor subjective health was significantly related to a higher risk of refusing vaccination. The results point to the importance of addressing the factors related to refusal. Only by understanding these factors will it be possible to increase vaccination rates and thus minimize other restrictive measures.

Outcomes of COVID-19 and risk factors in patients with cancer

Patients with cancer are at higher risk for adverse coronavirus disease 2019 (COVID-19) outcomes. Here, we studied 1,253 patients with cancer, who were diagnosed with severe acute respiratory syndrome coronavirus 2 at a tertiary referral cancer center in India. Most patients had mild disease; in our settings, recent cancer therapies did not impact COVID-19 outcomes. Advancing age, smoking history, concurrent comorbidities and palliative intent of treatment were independently associated with severe COVID-19 or death. Thus, our study provides useful insights into cancer management during the COVID-19 pandemic.

A new screening tool for SARS-CoV-2 infection based on self-reported patient clinical characteristics: the COV19-ID score

Background

While several studies aimed to identify risk factors for severe COVID-19 cases to better anticipate intensive care unit admissions, very few have been conducted on self-reported patient symptoms and characteristics, predictive of RT-PCR test positivity. We therefore aimed to identify those predictive factors and construct a predictive score for the screening of patients at admission.

Methods

This was a monocentric retrospective analysis of clinical data from 9081 patients tested for SARS-CoV-2 infection from August 1 to November 30 2020. A multivariable logistic regression using least absolute shrinkage and selection operator (LASSO) was performed on a training dataset (60% of the data) to determine associations between self-reported patient characteristics and COVID-19 diagnosis. Regression coefficients were used to construct the Coronavirus 2019 Identification score (COV₁₉-ID) and the optimal threshold calculated on the validation dataset (20%). Its predictive performance was finally evaluated on a test dataset (20%).

Results

A total of 2084 (22.9%) patients were tested positive to SARS-CoV-2 infection. Using the LASSO model, COVID-19 was independently associated with loss of smell (Odds Ratio, 6.4), fever (OR, 2.7), history of contact with an infected person (OR, 1.7), loss of taste (OR, 1.5), muscle stiffness (OR, 1.5), cough (OR, 1.5), back pain (OR, 1.4), loss of appetite (OR, 1.3), as well as male sex (OR, 1.05). Conversely, COVID-19 was less likely associated with smoking (OR, 0.5), sore throat (OR, 0.9) and ear pain (OR, 0.9). All aforementioned variables were included in the COV₁₉-ID score, which demonstrated on the test dataset an area under the receiver-operating characteristic curve of 82.9% (95% CI 80.6%–84.9%), and an accuracy of 74.2% (95% CI 74.1%–74.3%) with a high sensitivity (80.4%, 95% CI [80.3%–80.6%]) and specificity (72.2%, 95% CI [72.2%–72.4%]).

Conclusions

The COV₁₉-ID score could be useful in early triage of patients needing RT-PCR testing thus alleviating the burden on laboratories, emergency rooms, and wards.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07164-1.

Vaccines and Vaccination against SARS-CoV-2: Considerations for the Older Population

Age is among the most prominent risk factors for developing severe COVID-19 disease, and therefore older adults are a major target group for vaccination against SARS-CoV-2. This review focusses on age-associated aspects of COVID-19 vaccines and vaccination strategies, and summarizes data on immunogenicity, efficacy and effectiveness of the four COVID-19 vaccines, which are licensed in the US and/or Europe; namely, the two mRNA vaccines by BioNTech/Pfizer (BNT162b2) and Moderna (mRNA-1273), and the adenovector vaccines developed by AstraZeneca/University Oxford (ChAdOx1-nCoV-19, AZD1222) and Janssen/Johnson&Johnson (Ad26.COV2-S), respectively. After very high protection rates in the first months after vaccination even in the older population, effectiveness of the vaccines, particularly against asymptomatic infection and mild disease, declined at later time points and with the emergence of virus variants. Many high-income countries have recently started administration of additional doses to older adults and other high-risk groups, whereas other parts of the world are still struggling to acquire and distribute vaccines for primary vaccination. Other vaccines are available in other countries and clinical development for more vaccine candidates is ongoing, but a complete overview of COVID-19 vaccine development is beyond the scope of this article.

Racial Health Disparity and COVID-19

The infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and resultant coronavirus diseases-19 (COVID-19) disproportionally affects minorities, especially African Americans (AA) compared to the Caucasian population. The AA population is disproportionally affected by COVID-19, in part, because they have high prevalence of underlying conditions such as obesity, diabetes, and hypertension, which are known to exacerbate not only kidney diseases, but also COVID-19. Further, a decreased adherence to COVID-19 guidelines among tobacco smokers could result in increased infection, inflammation, reduced immune response, and lungs damage, leading to more severe form of COVID-19. As a result of high prevalence of underlying conditions that cause kidney diseases in the AA population coupled with tobacco smoking make the AA population vulnerable to severe form of both COVID-19 and kidney diseases. In this review, we describe how tobacco smoking interact with SARS-CoV-2 and exacerbates SARS-CoV-2-induced kidney diseases including renal failure, especially in the AA population. We also explore the role of extracellular vesicles (EVs) in COVID-19 patients who smoke tobacco. EVs, which play important role in tobacco-mediated pathogenesis in infectious diseases, have also shown to be important in COVID-19 pathogenesis and organ injuries including kidney. Further, we explore the potential role of EVs in biomarker discovery and therapeutics, which may help to develop early diagnosis and treatment of tobacco-induced renal injury in COVID-19 patients, respectively.

Chronic diseases associated with increased likelihood of hospitalization and mortality in 68,913 COVID-19 confirmed cases in Spain: A population-based cohort study

Background

Clinical outcomes among COVID-19 patients vary greatly with age and underlying comorbidities. We aimed to determine the demographic and clinical factors, particularly baseline chronic conditions, associated with an increased risk of severity in COVID-19 patients from a population-based perspective and using data from electronic health records (EHR).

Methods

Retrospective, observational study in an open cohort analyzing all 68,913 individuals (mean age 44.4 years, 53.2% women) with SARS-CoV-2 infection between 15 June and 19 December 2020 using exhaustive electronic health registries. Patients were followed for 30 days from inclusion or until the date of death within that period. We performed multivariate logistic regression to analyze the association between each chronic disease and severe infection, based on hospitalization and all-cause mortality.

Results

5885 (8.5%) individuals showed severe infection and old age was the most influencing factor. Congestive heart failure (odds ratio -OR- men: 1.28, OR women: 1.39), diabetes (1.37, 1.24), chronic renal failure (1.31, 1.22) and obesity (1.21, 1.26) increased the likelihood of severe infection in both sexes. Chronic skin ulcers (1.32), acute cerebrovascular disease (1.34), chronic obstructive pulmonary disease (1.21), urinary incontinence (1.17) and neoplasms (1.26) in men, and infertility (1.87), obstructive sleep apnea (1.43), hepatic steatosis (1.43), rheumatoid arthritis (1.39) and menstrual disorders (1.18) in women were also associated with more severe outcomes.

Conclusions

Age and specific cardiovascular and metabolic diseases increased the risk of severe SARS-CoV-2 infections in men and women, whereas the effects of certain comorbidities are sex specific. Future studies in different settings are encouraged to analyze which profiles of chronic patients are at higher risk of poor prognosis and should therefore be the targets of prevention and shielding strategies.

Survival of COVID-19 with Multimorbidity Patients

BACKGROUND

The outbreak of SARS-CoV-2 abruptly disseminated in early 2020, overcoming the capacity of health systems to respond the pandemic. It was not until the vaccines were launched worldwide that an increase in survival was observed. The objectives of this study were to analyse the characteristics of survivors and their relationship with comorbidities. We had access to a database containing information on 16,747 hospitalized patients from Mexico, all infected with SARS-CoV-2, as part of a regular follow-up. The descriptive analysis looked for clusters of either success or failure. We categorized the samples into no comorbidities, or one and up to five coexisting with the infection. We performed a logistic regression test to ascertain what factors were more influential in survival. The main variable of interest was survival associated with multimorbidity factors. The database hosted information on hospitalized patients from Mexico between March 2020 through to April 2021. Categories 2 and 3 had the largest number of patients. Survival rates were higher in categories 0 (64.8%), 1 (57.5%) and 2 (51.6%). In total, 1741 (10.5%) patients were allocated to an ICU unit. Mechanical ventilators were used on 1415 patients, corresponding to 8.76%. Survival was recorded in 9575 patients, accounting for 57.2% of the sample population. Patients without comorbidities, younger people and women were more likely to survive.

Vaccination of older adults: Influenza, pneumococcal disease, herpes zoster, COVID-19 and beyond

Preserving good health in old age is of utmost importance to alleviate societal, economic and health care-related challenges caused by an aging society. The prevalence and severity of many infectious diseases is higher in older adults, and in addition to the acute disease, long-term sequelae, such as exacerbation of underlying chronic disease, onset of frailty or increased long-term care dependency, are frequent. Prevention of infections e.g. by vaccination is therefore an important measure to ensure healthy aging and preserve quality of life. Several vaccines are specifically recommended for older adults in many countries, and in the current SARS-CoV-2 pandemic older adults were among the first target groups for vaccination due to their high risk for severe disease. This review highlights clinical data on the influenza, Streptococcus pneumoniae and herpes zoster vaccines, summarizes recent developments to improve vaccine efficacy, such as the use of adjuvants or higher antigen dose for influenza, and gives an overview of SARS-CoV-2 vaccine development for older adults. Substantial research is ongoing to further improve vaccines, e.g. by developing universal influenza and pneumococcal vaccines to overcome the limitations of the current strain-specific vaccines, and to develop novel vaccines against pathogens, which cause considerable morbidity and mortality in older adults, but for which no vaccines are currently available. In addition, we need to improve uptake of the existing vaccines and increase awareness for life-long vaccination in order to provide optimal protection for the vulnerable older age group.

Alterations in platelets during SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) is a pandemic syndrome caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. SARS-CoV-2 infection induces a process of inflammation and thrombosis supported by an altered platelet activation state. This platelet activation is peculiar being characterized by the formation of platelet-leukocytes rather than platelet–platelet aggregates and by an increased procoagulant potential supported by elevated levels of TF positive platelets and microvesicles.

Therapeutic strategies targeting, beyond systemic inflammation (i.e. with tocilizumab, an anti interleukin-6 receptor), this state of platelet activation might therefore be beneficial. Among the antithrombotic drugs proposed as candidates to treat patients with SARS-CoV-2 infection, antiplatelet drugs, such as aspirin are showing promising results.

Cross-National Variations in COVID-19 Mortality: The Role of Diet, Obesity and Depression

Background: The COVID-19 pandemic has been characterized by wide variations in mortality across nations. Some of this variability may be explained by medical comorbidities such as obesity and depression, both of which are strongly correlated with dietary practices such as levels of sugar and seafood consumption. Methods: COVID-19 mortality indices for 156 countries were obtained from the Johns Hopkins University’s data aggregator. Correlations between these variables and (a) per capita consumption of sugar and seafood, and (b) country-wise prevalence of depression and obesity were examined. Results: Sugar consumption (r = 0.51, p < 0.001) and prevalence of obesity (r = 0.66, p < 0.001) and depression (r = 0.56, p < 0.001) were positively correlated with crude mortality rates, while seafood consumption was negatively correlated with the infection fatality rate (r = −0.28, p = 0.015). These effects were significant even after correcting for potential confounders. The associations with depression and obesity remained significant upon multivariate regression. Conclusions: Both obesity and depression, which are associated with inflammatory dysregulation, may be related to cross-national variations in COVID-19 mortality, while seafood consumption may be protective. These findings have implications in terms of protecting vulnerable individuals during the current pandemic.