Vaccines for the common cold

The Path Towards Progress: A Critical Review to Advance the Science of the Female and Male Athlete Triad and Relative Energy Deficiency in Sport

Energy status plays a key role in the health of athletes and exercising individuals. Energy deficiency/low energy availability (EA), referring to a state in which insufficient energy intake and/or excessive exercise energy expenditure has resulted in compensatory metabolic adaptations to conserve fuel, can affect numerous physiological systems in women and men. The Female Athlete Triad, Male Athlete Triad, and Relative Energy Deficiency in Sport (RED-S) models conceptualize the effects of energy deficiency in athletes, and each model has strengths and limitations. For instance, the Female Athlete Triad model depicts relationships between low EA, reproductive, and bone health, underpinning decades of experimental evidence, but may be perceived as limited in scope, while the more recent RED-S model proposes a wider range of potential health effects of low EA, though many model components require more robust scientific justification. This critical review summarizes current evidence regarding the effects of energy deficiency on athlete health by addressing the quality of the underlying science, the strengths and limitations of each model, and highlighting areas where future research is needed to advance the field. With the health and wellness of athletes and exercising individuals as the overarching priority, we conclude with specific steps that will help focus future research on the Female and Male Athlete Triad and RED-S, and encourage all researchers, clinicians, and practitioners to collaborate to support the common goal of promoting the highest quality science and evidence-based medicine in pursuit of the advancement of athletes' health, well-being, and performance.

Interventions for preventing influenza: An overview of Cochrane systematic reviews and a Bayesian network meta-analysis

BACKGROUND

Influenza places a heavy public health burden in numerous countries every year. In addition to vaccines, there are some interventions that are effective in preventing influenza.

OBJECTIVE

This overview of systematic reviews (SRs) aimed to evaluate the efficacy and safety of interventions for influenza prevention.

SEARCH STRATEGY

We searched the Cochrane Database of Systematic Reviews, 2020, Issue 1 for relevant Cochrane SRs using the keywords "common cold," "influenza," and "flu."

INCLUSION CRITERIA

Cochrane SRs that investigated the prevention of influenza were included. Participants included the general population without influenza or influenza-like symptoms, who were treated with preventative interventions and compared to individuals receiving no treatment or placebo.

DATA EXTRACTION AND ANALYSIS

Two reviewers independently screened citations against pre-defined inclusion criteria and extracted data. The methodological quality of these SRs was evaluated using the Assessing the Methodological Quality of Systematic Reviews-II (AMSTAR-II) guidelines. The primary outcome of our analysis was the incidence of influenza, and the secondary outcomes were the incidence of influenza-like illness and hospitalization. In addition to the narrative summary of SR findings, we also pooled data from homogeneous trials among these SRs and produced evidence mapping. We conducted a network meta-analysis to compare the effect across interventions and used the Cochrane approach to grading of recommendations, assessment, development, and evaluation (GRADE) to assess the quality of evidence.

RESULTS

Eleven Cochrane SRs were included, covering five medications, eleven vaccinations and four complementary therapies. Among these SRs, 73% scored "high" quality on AMSTAR-II rating. We found that eight interventions, including amantadine, garlic, and six different vaccines, were beneficial for reducing the incidence of influenza compared to placebo, while oseltamivir, zanamivir, Ganmao capsule, Echinacea, and another three types of vaccine were probably beneficial. Ganmao capsule ranked highest for influenza prevention in the network meta-analysis, followed by amantadine, garlic, and vaccines of all types. Monovalent inactivated parenteral vaccine was found to be beneficial in reducing the incidence of influenza-like illness. None of the interventions reduced the hospitalization rate.

CONCLUSION

High-quality evidence showed that garlic or vaccine had advantages in preventing influenza, and that vitamin C is not effective. The effect of other interventions needs to be further verified with high-quality evidence.

Global burden of upper respiratory infections in 204 countries and territories, from 1990 to 2019

BACKGROUND

Upper respiratory infections (URIs) are among the most common diseases. However, the related burden has not been comprehensively evaluated. Thus, we designed the present study to describe the global and regional burden of URIs from 1990 to 2019.

METHODS

A secondary analysis was performed on the incidence, mortality, and disability-adjusted life years (DALYs) of URIs in different sex and age groups, from 21 geographic regions, 204 countries and territories, between 1990 and 2019, using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Countries and territories were categorized according to Socio-demographic Index (SDI) quintiles.

FINDINGS

Globally, the incident cases of URIs reached 17·2 (95% uncertainty interval: 15·4 to 19·3) billion in 2019, which accounted for 42·83% (40·01% to 45·77%) cases from all causes in the GBD 2019 study. The age-standardized incidence rate remained stable from 1990 to 2019, while significant decreases were found in the mortality and DALY rate. The highest age-standardized incidence rates from 1990 to 2019 and the highest age-standardized DALY rates after 2011 were observed in high SDI regions. Among all the age groups, children under five years old suffered from the highest incidence and DALY rates, both of which were decreased with increasing age. Fatal consequences of URIs occurred mostly in the elderly and children under five years old.

INTERPRETATION

The present study provided comprehensive estimates of URIs burden for the first time. Our findings, highlighting the substantial incidence and considerable DALYs due to URIs, are expected to attract more attention to URIs and provide future explorations in the prevention and treatment with epidemiological evidence.

FUNDING

The study was funded by the National Natural Science Foundation of China (81770057).

Boosting nitric oxide in stress and respiratory infection: Potential relevance for asthma and COVID-19

Nitric oxide (NO) is a ubiquitous signaling molecule that is critical for supporting a plethora of processes in biological organisms. Among these, its role in the innate immune system as a first line of defense against pathogens has received less attention. In asthma, levels of exhaled NO have been utilized as a window into airway inflammation caused by allergic processes. However, respiratory infections count among the most important triggers of disease exacerbations. Among the multitude of factors that affect NO levels are psychological processes. In particular, longer lasting states of psychological stress and depression have been shown to attenuate NO production. The novel SARS-CoV-2 virus, which has caused a pandemic, and with that, sustained levels of psychological stress globally, also adversely affects NO signaling. We review evidence on the role of NO in respiratory infection, including COVID-19, and stress, and argue that boosting NO bioavailability may be beneficial in protection from infections, thus benefitting individuals who suffer from stress in asthma or SARS-CoV-2 infection.

Safety and efficacy of iota-carrageenan nasal spray in treatment and prevention of the common cold

The common cold is one of the most frequent viral infections in humans. Although benign, its symptoms result in economic burden and can lead to severe or even fatal complications in children, elderly and groups with comorbidities. The main purpose of the treatment is the relief of symptoms; however, the medication is often associated with adverse effects. Iota-carrageenan is a polysaccharide that reveals antiviral activity by binding to viruses, inhibiting its replications and, consequently, its viral propagation. This systematic review of the literature aims to compare the effectiveness of an iota-carrageenan nasal spray to placebo. This systematic review was conducted through research in Cochrane Database, PubMed, Science Direct, SpringerLink, Oxford Journals, Elsevier, ClinicalKey, Wiley Online Library, Embase databases, in order to collect randomized and controlled clinical trials. In total, the research provided four articles regarding clinical trials for comparing iota-carrageenan nasal spray with placebo. The results show it has potent antiviral activity compared to placebo and a favorable safety profile. Although further research is needed, the concept of a physical barrier capable of reducing viral penetration of epithelial cells in the nasal mucosa is appealing, and could lead to alternative approaches, with positive impact on global health.

Intake of 25-Hydroxyvitamin D3 May Reduce the Severity of Upper Respiratory Tract Infection: Post hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study

To evaluate the effects of 25-hydroxyvitamin D₃ (25OHD) on symptoms at the onset of the upper respiratory tract infection (URTI) in subjects with insufficient or deficient serum 25-hydroxyvitamin D levels, we conducted a post hoc analysis of data from a randomized, placebo-controlled study; the subjects received 10 μg of 25OHD per day or a placebo for 16 weeks. The Wisconsin Upper Respiratory Symptom Survey-21 was used to determine URTI. The study endpoints included WURSS-21 scores, number of URTI events, and proportion of medication (antibiotics, antipyretic analgesics) usage. We found that the physical symptom scores for "Runny nose," "Sneezing," and "Head congestion" were significantly lower in the 25OHD group than in the placebo group; for all items except "Breathe easily, "the quality of life" scores were significantly improved in the 25OHD group. There was no significant difference in the number of URTI events or the proportion of medication use between the groups. Collectively, the findings of this study indicate that a sufficient 25OHD intake can reduce physical symptoms at the onset of upper respiratory tract infection, particularly nasal symptoms, and may improve the quality of life at the time of onset.

Potential common factors associated with predisposition to common cold in middle-aged and elderly Japanese: A community-based cross-sectional study

People worldwide frequently catch a common cold, which occasionally develops into secondary severe conditions such as pneumonia. However, it is unclear whether predisposition to the common cold is associated with the individual's characteristics including age, body weight, lifestyles, diets, and intestinal functions, besides exposure to a responsible pathogen. We addressed this issue epidemiologically considering many relevant clinical factors.We reviewed data from a cross-sectional study consisting of 39,524 apparently healthy Japanese aged 40 to 79 years (26,975 men and 12,549 women) who underwent a checkup in 2007. Self-reported predisposition to common cold (SPCC) and relevant clinical conditions and parameters were considered.We observed no significant difference in most clinical parameters including age, body mass index (BMI), glycated hemoglobin (HbA1c), and prevalence of men and current smokers between subjects with and without SPCC. In univariate analysis, circulating white blood cell (WBC) count and serum alanine-aminotransferase (ALT) were significantly higher in subjects with SPCC than in those without, whereas serum high-density lipoprotein cholesterol (HDL-C) and duration of sleep were lower. In logistic regression analysis after full adjustment for relevant confounding factors, BMI categories except BMI of ≥27.0 kg/m were significantly associated with SPCC compared with BMI of 23.0 to 24.9 kg/m. Short duration of sleep (≤5 hours), occasional alcohol drinking, and no-exercise were significantly associated with SPCC compared with 7 hours sleep duration, no-drinking alcohol, and low frequent exercise (twice per month), respectively. All gastrointestinal disorders (gastric complaints, constipation, and diarrhea) were independently associated with SPCC. Imbalanced diet and taking a snack were also associated with SPCC in a degree dependent manner. Furthermore, WBC count, serum ALT, and HDL-C (as continuous variables) were associated with SPCC (HDL-C was inversely), whereas no significant association was observed between SPCC and age, smoking, HbA1c, and pharmacotherapy for diabetes, hypertension, and dyslipidemia.Our results demonstrated that multifactorial conditions and parameters might be simultaneously associated with the predisposition to common cold. Prospective studies including detailed common cold questionnaire and measurements are needed to confirm currently suspected causative and protective factors.

Home dampness-related exposures increase the risk of common colds among preschool children in Shanghai, China: Modified by household ventilation

Few studies have estimated the effects of dampness-related exposures and its interaction effects with poor household ventilation on common colds of preschool children. During April 2011-April 2012, we conducted a cross-sectional survey on home environment and childhood health and collected 13,335 parents-reported questionnaires of 4-6 year-old children in Shanghai, China. In this paper, we investigated associations between the incidence and duration of common colds among these children during the past 12 months before the survey and frequency of opening windows, as well as household dampness-related exposures (indicated by six dampness indicators). Significantly higher incidence (≥3 times) and longer duration (≥2 weeks) of common cold were found among children with than without these dampness exposures (p-value <0.01 for mold spots and p-value <0.001 for all other indicators). The number of dampness-related indicators had a positive and strong dose-response relationship with common colds (p-trend <0.01). Low frequency of ventilation was also a risk factor for children common colds. After adjusted for the potential confounders in the multiple logistic regression analyses, all dampness-related indicators were significantly associated with the increased odds of common colds and the highest odds ratios was 1.21 (95% CI: 1.16-1.27). We also found that dampness-related exposures and household ventilation habits (p-value for interaction <0.001) had a strong interaction effect on the incidence and duration of common cold. The stratified analysis of ventilation condition displays that the influence of dampness-related exposures has been modified by ventilation. Therefore, good household ventilation habits may have an effect of modification for dampness-related exposures.