The Association between Influenza and Pneumococcal Vaccinations and SARS-Cov-2 Infection: Data from the EPICOVID19 Web-Based Survey

Vaccination against influenza viruses reduces infection, not hospitalization or death, from respiratory COVID-19: A systematic review and meta-analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and has brought a huge burden in terms of human lives. Strict social distance and influenza vaccination have been recommended to avoid co-infections between influenza viruses and SARS-CoV-2. Scattered reports suggested a protective effect of influenza vaccine on COVID-19 development and severity. We analyzed 51 studies on the capacity of influenza vaccination to affect infection with SARS-CoV-2, hospitalization, admission to Intensive Care Units (ICU), and mortality. All subjects taken into consideration did not receive any anti-SARS-CoV-2 vaccine, although their status with respect to previous infections with SARS-CoV-2 is not known. Comparison between vaccinated and not-vaccinated subjects for each of the four endpoints was expressed as odds ratio (OR), with 95% confidence intervals (CIs); all analyses were performed by DerSimonian and Laird model, and Hartung-Knapp model when studies were less than 10. In a total of 61 029 936 subjects from 33 studies, influenza vaccination reduced frequency of SARS-CoV-2 infection [OR plus 95% CI = 0.70 (0.65-0.77)]. The effect was significant in all studies together, in health care workers and in the general population; distance from influenza vaccination and the type of vaccine were also of importance. In 98 174 subjects from 11 studies, frequency of ICU admission was reduced with influenza vaccination [OR (95% CI) = 0.71 (0.54-0.94)]; the effect was significant in all studies together, in pregnant women and in hospitalized subjects. In contrast, in 4 737 328 subjects from 14 studies hospitalization was not modified [OR (95% CI) = 1.05 (0.82-1.35)], and in 4 139 660 subjects from 19 studies, mortality was not modified [OR (95% CI) = 0.76 (0.26-2.20)]. Our study emphasizes the importance of influenza vaccination in the protection against SARS-CoV-2 infection.

Influenza vaccine effectiveness against hospitalized SARS-CoV-2 infection

Background

Some studies conducted before the Delta and Omicron variant-dominant periods have indicated that influenza vaccination provided protection against COVID-19 infection or hospitalization, but these results were limited by small study cohorts and a lack of comprehensive data on patient characteristics. No studies have examined this question during the Delta and Omicron periods (08/01/2021 to 2/22/2022).

Methods

We conducted a retrospective cohort study of influenza-vaccinated and unvaccinated patients in the Corewell Health East(CHE, formerly known as Beaumont Health), Corewell Health West(CHW, formerly known as Spectrum Health) and Michigan Medicine (MM) healthcare system during the Delta-dominant and Omicron-dominant periods. We used a test-negative, case-control analysis to assess the effectiveness of the influenza vaccine against hospitalized SARS-CoV-2 outcome in adults, while controlling for individual characteristics as well as pandameic severity and waning immunity of COVID-19 vaccine.

Results

The influenza vaccination has shown to provided some protection against SARS-CoV-2 hospitalized outcome across three main healthcare systems. CHE site (odds ratio [OR]=0.73, vaccine effectiveness [VE]=27%, 95% confidence interval [CI]: [18-35], p<0.001), CHW site (OR=0.85, VE=15%, 95% CI: [6-24], p<0.001), MM (OR=0.50, VE=50%, 95% CI: [40-58], p <0.001) and overall (OR=0.75, VE=25%, 95% CI: [20-30], p <0.001).

Conclusion

The influenza vaccine provides a small degree of protection against SARS-CoV-2 infection across our study sites.

Nitrous Oxide Inhalant Abuse: Preliminary Results from a Cross-Sectional Study on Knowledge, Attitudes, and Practices of Italian Physicians (2023)

Background and Objectives: Nitrous oxide (N2O) has recently emerged as a cheap alternative to other recreational substances. Although legally available, its chronic use is associated with severe neurological and hematological complications due to the irreversible inactivation of vitamin B12. While no reliable data on abuse of N2O in Italy have been provided to date, we assessed the knowledge, attitudes, and practices of Italian medical professionals on the management of N2O abuse cases. Materials and Methods: A cross-sectional study was performed as a web-based survey through a series of Facebook discussion groups (targeted medical professionals: 12,103), and participants were specifically asked about their previous understanding of N2O abuse and whether they had or not any previous experience in this topic. Results: A total 396 medical professionals participated in the survey. Overall, 115 participants had previous knowledge about N2O abuse (29.04%), with higher odds for professionals with a background in emergency medicine (adjusted odds ratio (aOR) 3.075; 95% confidence intervals (95%CI) 1.071 to 8.828) and lower for specialists in psychiatry (aOR 0.328; 95%CI 0.130 to 0.825). Knowledge status on N2O abuse was largely unsatisfying, as knowledge status, reported as a percent value, was estimated to 45.33% ± 24.71. Having previously managed a case of N2O abuse was associated with higher risk perception of the actual severity of this condition (aOR 5.070; 95%CI 1.520 to 16.980). Conclusions: Our study suggests that N2O poisoning cases are occurring in Italian settings but are not reasonably reported to national authorities. As substantial knowledge gaps of Italian medical workforces were identified, we cannot rule out that the actual abuse of N2O in the population may be far larger than currently suspected.

Lower risk for COVID-19 hospitalization among patients in the United States with past vaccinations for herpes zoster and tetanus, diphtheria and pertussis

Influenza, tetanus, diphtheria, and herpes zoster (HZ) vaccination received within 10 years of the COVID-19 pandemic have been associated with less severe COVID-19 infection. We expanded on this evidence to determine if a receiving two different vaccinations (i.e., HZ and tetanus, diphtheria, and pertussis (Tdap)) was associated with a lower risk for COVID-19 hospitalization. De-identified medical record data from a large mid-western health care system was used to determine if, compared to those with neither HZ or Tdap vaccination, patients with either HZ or Tdap and patients with both HZ and Tdap vaccination had lower risk for COVID-19 hospitalization between 4/1/2020 and 12/31/2020. Confounding was controlled using entropy balancing. Patients (n = 363,293) were 71.5 (±8.4) years of age, 57.8% female and 89.2% White race. Prior to controlling for confounding, as compared to patients without either vaccination, those that had either HZ or Tdap were significantly less likely to have a COVID-19 hospitalization (RR = 0.85; 95 %CI: 0.75-0.95). The risk for hospitalization decreased further among those with both HZ and Tdap vaccination (RR = 0.45; 95 %CI:0.28-0.71). After controlling for confounding, including healthy patient bias, receiving both vs. neither vaccinations remained significantly associated with a lower risk of COVID-19 hospitalization (RR = 0.48; 95 %CI: 0.26-0.90). Receiving both Tdap and HZ vaccination is associated with lower risk for COVID-19 hospitalization. Whether there is any benefit of past vaccination exposure in COVID-19 vaccinated patients should be investigated.

SARS-CoV-2 and Its Bacterial Co- or Super-Infections Synergize to Trigger COVID-19 Autoimmune Cardiopathies

Autoimmune cardiopathies (AC) following COVID-19 and vaccination against SARS-CoV-2 occur at significant rates but are of unknown etiology. This study investigated the possible roles of viral and bacterial mimicry, as well as viral-bacterial co-infections, as possible inducers of COVID-19 AC using proteomic methods and enzyme-linked immunoadsorption assays. BLAST and LALIGN results of this study demonstrate that SARS-CoV-2 shares a significantly greater number of high quality similarities to some cardiac protein compared with other viruses; that bacteria such as Streptococci, Staphylococci and Enterococci also display very significant similarities to cardiac proteins but to a different set than SARS-CoV-2; that the importance of these similarities is largely validated by ELISA experiments demonstrating that polyclonal antibodies against SARS-CoV-2 and COVID-19-associated bacteria recognize cardiac proteins with high affinity; that to account for the range of cardiac proteins targeted by autoantibodies in COVID-19-associated autoimmune myocarditis, both viral and bacterial triggers are probably required; that the targets of the viral and bacterial antibodies are often molecularly complementary antigens such as actin and myosin, laminin and collagen, or creatine kinase and pyruvate kinase, that are known to bind to each other; and that the corresponding viral and bacterial antibodies recognizing these complementary antigens also bind to each other with high affinity as if they have an idiotype-anti-idiotype relationship. These results suggest that AC results from SARS-CoV-2 infections or vaccination complicated by bacterial infections. Vaccination against some of these bacterial infections, such as Streptococci and Haemophilus, may therefore decrease AC risk, as may the appropriate and timely use of antibiotics among COVID-19 patients and careful screening of vaccinees for signs of infection such as fever, diarrhea, infected wounds, gum disease, etc.

The Effect of Combining the COVID-19 Vaccine with the Seasonal Influenza Vaccine on Reducing COVID-19 Vaccine Rejection Among Libyans

BACKGROUND

Coronavirus disease 2019 (COVID-19) vaccine coverage remains low in Libya compared to other countries in the Eastern Mediterranean Region. This study aimed to evaluate the willingness of the general public in Libya to receive COVID-19 and seasonal influenza vaccines. Additionally, the study aimed to investigate the potential effect of combining the two vaccines to reduce COVID-19 vaccine rejection.

METHODS

An anonymous nationwide online cross-sectional survey was carried out from 1st September to 16th October 2022. Libyans aged 18 years or older were recruited using convenience and snowball sampling approaches. The participants were surveyed for sociodemographic information, health status, and vaccination attitude towards COVID-19 and seasonal influenza vaccines.

RESULTS

A total of 2484 participants formed the final study sample: 68.7% were females, 39.4% were aged 18-25 years, 50.4% were single, 32.5% had previous COVID-19 infection, and 47.2% experienced COVID-19 death among relatives. Three-fourths of the respondents showed COVID-19 vaccine rejection: 57.3% did not receive COVID-19 vaccination, 10.1% would not complete the primary vaccination series, and 7.8% refused booster doses. About 55.0% rejected seasonal influenza vaccination, while 1.9% reported influenza vaccine uptake and 21.2% were willing to get the influenza vaccine for the first time. Additionally, 18.8% had already received influenza vaccination in the last year and intended to get the vaccine this season, while 3.3% were unwilling to get influenza vaccination this year despite receiving it in the last influenza season. Age, sex, and occupation were significantly associated with COVID-19 and influenza vaccine rejection. Rejection of COVID-19 vaccination decreased if its combination with influenza vaccine as a single dose was suggested, with 28.2% of the COVID-19 vaccine rejector group accepting the combined vaccine as it would be safer (50.9%), needing fewer injections (24.0%), would be more effective (19.1%), and would be less expensive (3%). Approximately 73.0% of the COVID-19 vaccine rejector group refused this combination due to fear of side effects (48.7%), absence of published studies on this combination (29.8%), and considering this combination as useless (11.2%).

CONCLUSION

In Libya, the prevalence of COVID-19 vaccine rejection was high, while the rejection of seasonal influenza vaccination was relatively lower. If influenza and COVID-19 vaccines are administered simultaneously as a single injection, this may reduce the rejection of the COVID-19 vaccine due to better-perceived vaccine safety and efficacy besides being more convenient in terms of the number of injections and cost.

The Effect of Pneumococcal, Influenza, and COVID-19 Vaccinations on COVID-19 Hospitalization and Progression in People over 65 Years Old Living in Nursing Homes

Infectious diseases pose a major threat to elderly populations. Streptococcus pneumonia bacteria, influenza-causing viruses, and COVID-19 viruses cause three pathologies in the respiratory system with similar symptoms, transmission routes, and risk factors. Our study aimed to evaluate the effects of pneumococcal, influenza, and COVID-19 vaccinations on the status of COVID-19 hospitalization and progression in people over 65 years of age living in nursing homes. This study was performed in all nursing homes and elderly care centers in the Uskudar district of Istanbul.The diagnosis rate of COVID-19 was determined as 49%, the rate of hospitalization as 22.4%, the rate of hospitalization in the intensive care unit as 12.2%. The rate of intubation was determined as 10.4%, the rate of mechanical ventilation as 11.1% and the rate of COVID-19 related mortality rate as 9.7%. When the factors affecting the diagnosis of COVID-19 were examined, the presence and dose of COVID-19 vaccine was protective. When the factors affecting hospitalization status were examined, male sex and presence of chronic disease were risk factors; four doses of COVID-19 vaccine and influenza vaccine and pneumococcal vaccine together with COVID-19 vaccine were protective. When the factors affecting COVID-19-related death were examined, the male sex was a risk factor; the pneumococcal and influenza vaccine together with COVID-19 vaccine were protective. Our results revealed that the availability of influenza and pneumococcal vaccines positively impacted the progression of COVID-19 disease in the elderly population living in nursing homes.

From Co-Infections to Autoimmune Disease via Hyperactivated Innate Immunity: COVID-19 Autoimmune Coagulopathies, Autoimmune Myocarditis and Multisystem Inflammatory Syndrome in Children

Neutrophilia and the production of neutrophil extracellular traps (NETs) are two of many measures of increased inflammation in severe COVID-19 that also accompany its autoimmune complications, including coagulopathies, myocarditis and multisystem inflammatory syndrome in children (MIS-C). This paper integrates currently disparate measures of innate hyperactivation in severe COVID-19 and its autoimmune complications, and relates these to SARS-CoV-2 activation of innate immunity. Aggregated data include activation of Toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD) receptors, NOD leucine-rich repeat and pyrin-domain-containing receptors (NLRPs), retinoic acid-inducible gene I (RIG-I) and melanoma-differentiation-associated gene 5 (MDA-5). SARS-CoV-2 mainly activates the virus-associated innate receptors TLR3, TLR7, TLR8, NLRP3, RIG-1 and MDA-5. Severe COVID-19, however, is characterized by additional activation of TLR1, TLR2, TLR4, TLR5, TLR6, NOD1 and NOD2, which are primarily responsive to bacterial antigens. The innate activation patterns in autoimmune coagulopathies, myocarditis and Kawasaki disease, or MIS-C, mimic those of severe COVID-19 rather than SARS-CoV-2 alone suggesting that autoimmunity follows combined SARS-CoV-2-bacterial infections. Viral and bacterial receptors are known to synergize to produce the increased inflammation required to support autoimmune disease pathology. Additional studies demonstrate that anti-bacterial antibodies are also required to account for known autoantigen targets in COVID-19 autoimmune complications.

T Cell Receptor Sequences Amplified during Severe COVID-19 and Multisystem Inflammatory Syndrome in Children Mimic SARS-CoV-2, Its Bacterial Co-Infections and Host Autoantigens

Published hypervariable region V-beta T cell receptor (TCR) sequences were collected from people with severe COVID-19 characterized by having various autoimmune complications, including blood coagulopathies and cardiac autoimmunity, as well as from patients diagnosed with the Kawasaki disease (KD)-like multisystem inflammatory syndrome in children (MIS-C). These were compared with comparable published v-beta TCR sequences from people diagnosed with KD and from healthy individuals. Since TCR V-beta sequences are supposed to be complementary to antigens that induce clonal expansion, it was surprising that only a quarter of the TCR sequences derived from severe COVID-19 and MIS-C patients mimicked SARS-CoV-2 proteins. Thirty percent of the KD-derived TCR mimicked coronaviruses other than SARS-CoV-2. In contrast, only three percent of the TCR sequences from healthy individuals and those diagnosed with autoimmune myocarditis displayed similarities to any coronavirus. In each disease, significant increases were found in the amount of TCRs from healthy individuals mimicking specific bacterial co-infections (especially Enterococcus faecium, Staphylococcal and Streptococcal antigens) and host autoantigens targeted by autoimmune diseases (especially myosin, collagen, phospholipid-associated proteins, and blood coagulation proteins). Theoretical explanations for these surprising observations and implications to unravel the causes of autoimmune diseases are explored.

Maintaining a 'fit' immune system: the role of vaccines

INTRODUCTION

Conventionally, vaccines are thought to induce a specific immune response directed against a target pathogen. Long recognized but poorly understood nonspecific benefits of vaccination, such as reduced susceptibility to unrelated diseases or cancer, are now being investigated and may be due in part to "trained immunity'.

AREAS COVERED

We discuss 'trained immunity' and whether vaccine-induced 'trained immunity' could be leveraged to prevent morbidity due to a broader range of causes.

EXPERT OPINION

The prevention of infection i.e. maintaining homeostasis by preventing the primary infection and resulting secondary illnesses, is the pivotal strategy used to direct vaccine design and may have long-term, positive impacts on health at all ages. In the future, we anticipate that vaccine design will change to not only prevent the target infection (or related infections) but to generate positive modifications to the immune response that could prevent a wider range of infections and potentially reduce the impact of immunological changes associated with aging. Despite changing demographics, adult vaccination has not always been prioritized. However, the SARS-CoV-2 pandemic has demonstrated that adult vaccination can flourish given the right circumstances, demonstrating that harnessing the potential benefits of life-course vaccination is achievable for all.

The Effect of the COVID-19 Pandemic on Vaccination Behaviour of Individuals over the Age of 65 Years in Turkey: Single-Centre Experience

The aim of this study is to evaluate the awareness of individuals over 65 years of age who have had the COVID-19 vaccine at the Samsun Research and Training Hospital and to evaluate whether the COVID-19 pandemic affected the vaccination behaviour in the geriatric age group. A total of 290 people who were vaccinated against COVID-19 at the Samsun Training and Research Hospital between 16 April 2021 and 16 April 2022 and volunteered to participate in the study were included. The questionnaire form was created by the researchers. According to the national and global guidelines, the seasonal influenza vaccine, Td or Tdap vaccines (tetanus, diphtheria, and pertussis), shingles vaccine, and pneumococcal conjugate vaccine (PCV15 or PCV20), have been recommended to all adults over the age of 65. It was questioned whether the participants had the vaccines recommended for them before and after the pandemic, if they were not vaccinated, what were the reasons, and whether the COVID-19 pandemic affected the general view on vaccination in this age group. Demographic data and comorbidities were also recorded. After each response that showed that the participant was not vaccinated, reasons were investigated with new questions to find out the causes of vaccine refusal or vaccine hesitancy. Finally, all participants were asked whether they would have the relevant vaccinations when offered. It was shown that 282 (94.3%) of the 299 people who participated in the study were considering getting a regular COVID-19 vaccine from now on, while 84.3% of the participants mentioned that the COVID-19 pandemic had a positive effect on their general vaccination behaviour. While 39 (13%) people stated that their view on vaccination was not affected by the pandemic, 8 (2.7%) people stated that it was negatively affected. The most common reason about low vaccination rates before the pandemic was a lack of enough knowledge about the recommended vaccines. The pandemic increased the vaccination awareness among the adult population. We think that vaccination rates may be improved by education of the geriatric population on this subject.

Influenza and Pneumococcal Vaccination and the Risk of COVID-19: A Systematic Review and Meta-Analysis

A number of studies have investigated the potential on-specific effects of some routinely administered vaccines (e.g., influenza, pneumococcal) on COVID-19 related outcomes, with contrasting results. In order to elucidate this discrepancy, we conducted a systematic review and meta-analysis to assess the association between seasonal influenza vaccination and pneumococcal vaccination with SARS-CoV-2 infection and its clinical outcomes. PubMed and medRxiv databases were searched up to April 2022. A random effects model was used in the meta-analysis to pool odds ratio (OR) and adjusted estimates with 95% confidence intervals (CIs). Heterogeneity was quantitatively assessed using the Cochran's Q and the I2 index. Subgroup analysis, sensitivity analysis and assessment of publication bias were performed for all outcomes. In total, 38 observational studies were included in the meta-analysis and there was substantial heterogeneity. Influenza and pneumococcal vaccination were associated with lower risk of SARS-CoV-2 infection (OR: 0.80, 95% CI: 0.75-0.86 and OR: 0.70, 95% CI: 0.57-0.88, respectively). Regarding influenza vaccination, it seems that the majority of studies did not properly adjust for all potential confounders, so when the analysis was limited to studies that adjusted for age, gender, comorbidities and socioeconomic indices, the association diminished. This is not the case regarding pneumococcal vaccination, for which even after adjustment for such factors the association persisted. Regarding harder endpoints such as ICU admission and death, current data do not support the association. Possible explanations are discussed, including trained immunity, inadequate matching for socioeconomic indices and possible coinfection.

Pre-existing mental health disorders and fear of COVID-19 pandemic: Data from a phone survey in community-dwelling older adults recruited in the NutBrain study

Background

COVID-19 has caused a parallel epidemic of fear, anxiety, depression, stress, and frustration, particularly among the most fragile and vulnerable individuals, such as older people and those with previous mental health disorders. The present study aims to investigate the association between pre-existing mental health disorders, particularly depressive symptoms and Mild Cognitive Impairment (MCI), and the fear of COVID-19 and to explore which cognitive domains were involved in coping with fear in older people.

Materials and methods

In April 2020, we conducted a phone-interview questionnaire on community-dwelling older adults living in Lombardy Region (Italy) who participated in the NutBrain study. At baseline, socio-demographic characteristics along with lifestyles, and medical history were recorded. Participants underwent a neuropsychological battery exploring the global cognitive function and specific cognitive domains, to detect cases of MCI. The Center for Epidemiologic Studies Depression scale (CES-D) was used for screening depressive symptoms. During the phone survey, respondents were assessed using a structured questionnaire querying about fear of the COVID-19 pandemic. We performed multivariate logistic regression models to study the association between MCI and depressive symptomatology and fear. We also explored which cognitive domains were associated with fear. Odds Ratios (OR) with Confidence Intervals (95%CI) were estimated adjusting for potential confounders.

Results

Out of the 351 respondents (mean age 73.5 ± 6.1 years, 59.8% women, 49.1% high education), at baseline, 22.9% had MCI and 18.8% had depressive symptoms. In the multivariate analyses gender, age, and body mass index were significantly associated with the fear score. Considering different domains of fear, MCI was associated with fear of being infected themselves (OR 2.55, 95%CI 1.39-4.70) while depressive symptoms were associated with fear of contagion for family members (OR 2.38, 95%CI 1.25-4.52). Impaired executive cognitive function was positively associated with the highest tertile of the fear score (OR 3.28, 95%CI 1.37-7.74) and with fear of contagion for themselves (OR 3.39, 95%CI 1.61-7.17).

Conclusion

Older adults experienced different fear reactions, particularly when suffering from neurocognitive disorders and depressive symptoms; executive dysfunction was associated with increased fear. These results highlighted the need to pay attention to the psychological effects of the outbreak of COVID-19 to target intervention, especially among vulnerable subgroups of individuals.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT04461951].

Machine-Learning-Assisted Analysis of TCR Profiling Data Unveils Cross-Reactivity between SARS-CoV-2 and a Wide Spectrum of Pathogens and Other Diseases

During the last two years, the emergence of SARS-CoV-2 has led to millions of deaths worldwide, with a devastating socio-economic impact on a global scale. The scientific community's focus has recently shifted towards the association of the T cell immunological repertoire with COVID-19 progression and severity, by utilising T cell receptor sequencing (TCR-Seq) assays. The Multiplexed Identification of T cell Receptor Antigen (MIRA) dataset, which is a subset of the immunoACCESS study, provides thousands of TCRs that can specifically recognise SARS-CoV-2 epitopes. Our study proposes a novel Machine Learning (ML)-assisted approach for analysing TCR-Seq data from the antigens' point of view, with the ability to unveil key antigens that can accurately distinguish between MIRA COVID-19-convalescent and healthy individuals based on differences in the triggered immune response. Some SARS-CoV-2 antigens were found to exhibit equal levels of recognition by MIRA TCRs in both convalescent and healthy cohorts, leading to the assumption of putative cross-reactivity between SARS-CoV-2 and other infectious agents. This hypothesis was tested by combining MIRA with other public TCR profiling repositories that host assays and sequencing data concerning a plethora of pathogens. Our study provides evidence regarding putative cross-reactivity between SARS-CoV-2 and a wide spectrum of pathogens and diseases, with M. tuberculosis and Influenza virus exhibiting the highest levels of cross-reactivity. These results can potentially shift the emphasis of immunological studies towards an increased application of TCR profiling assays that have the potential to uncover key mechanisms of cell-mediated immune response against pathogens and diseases.

Detection of pneumococcus during hospitalization for SARS-CoV-2

Background

Infections with respiratory viruses [e.g. influenza and respiratory syncytial virus (RSV)] can increase the risk of severe pneumococcal infections. Likewise, pneumococcal coinfection is associated with poorer outcomes in viral respiratory infection. However, there are limited data describing the frequency of pneumococcus and SARS-CoV-2 coinfection and the role of coinfection in influencing COVID-19 severity. We, therefore, investigated the detection of pneumococcus in COVID-19 inpatients during the early pandemic period.

Methods

The study included patients aged 18 years and older, admitted to the Yale-New Haven Hospital who were symptomatic for respiratory infection and tested positive for SARS-CoV-2 during March-August 2020. Patients were tested for pneumococcus through culture-enrichment of saliva followed by RT-qPCR (to identify carriage) and serotype-specific urine antigen detection (UAD) assays (to identify presumed lower respiratory tract pneumococcal disease).

Results

Among 148 subjects, the median age was 65 years; 54.7% were male; 50.7% had an ICU stay; 64.9% received antibiotics; and 14.9% died while admitted. Pneumococcal carriage was detected in 3/96 (3.1%) individuals tested by saliva RT-qPCR. Additionally, pneumococcus was detected in 14/127 (11.0%) individuals tested by UAD, and more commonly in severe than moderate COVID-19 [OR: 2.20; 95% CI: (0.72, 7.48)]; however, the numbers were small with a high degree of uncertainty. None of the UAD-positive individuals died.

Conclusions

Pneumococcal lower respiratory tract infection (LRTI), as detected by positive UAD, occurred in patients hospitalized with COVID-19. Moreover, pneumococcal LRTI was more common in those with more serious COVID-19 outcomes. Future studies should assess how pneumococcus and SARS-CoV-2 interact to influence COVID-19 severity in hospitalized patients.

Association between influenza vaccination and SARS-CoV-2 infection and its outcomes: systematic review and meta-analysis

BACKGROUND

World Health Organization recommends that influenza vaccines should benefit as much of the population as possible, especially where resources are limited. Corona virus disease 2019 (COVID-19) has become one of the greatest threats to health systems worldwide. The present study aimed to extend the evidence of the association between influenza vaccination and COVID-19 to promote the former.

METHODS

In this systematic review, four electronic databases, including the Cochrane Library, PubMed, Embase, and Web of Science, were searched for related studies published up to May 2022. All odds ratios (ORs) with 95% confidence intervals (CIs) were pooled by meta-analysis.

RESULTS

A total of 36 studies, encompassing 55,996,841 subjects, were included in this study. The meta-analysis for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection provided an OR of 0.80 (95% CI: 0.73-0.87). The statistically significant estimates for clinical outcomes were 0.83 (95% CI: 0.72-0.96) for intensive care unit admission, 0.69 (95% CI: 0.57-0.84) for ventilator support, and 0.69 (95% CI: 0.52-0.93) for fatal infection, while no effect seen in hospitalization with an OR of 0.87 (95% CI: 0.68-1.10).

CONCLUSION

Influenza vaccination helps limit SARS-CoV-2 infection and severe outcomes, but further studies are needed.

REGISTRATION

PROSPERO, CRD42022333747.

Complementary Sets of Autoantibodies Induced by SARS-CoV-2, Adenovirus and Bacterial Antigens Cross-React with Human Blood Protein Antigens in COVID-19 Coagulopathies

COVID-19 patients often develop coagulopathies including microclotting, thrombotic strokes or thrombocytopenia. Autoantibodies are present against blood-related proteins including cardiolipin (CL), serum albumin (SA), platelet factor 4 (PF4), beta 2 glycoprotein 1 (β2GPI), phosphodiesterases (PDE), and coagulation factors such as Factor II, IX, X and von Willebrand factor (vWF). Different combinations of autoantibodies associate with different coagulopathies. Previous research revealed similarities between proteins with blood clotting functions and SARS-CoV-2 proteins, adenovirus, and bacterial proteins associated with moderate-to-severe COVID-19 infections. This study investigated whether polyclonal antibodies (mainly goat and rabbit) against these viruses and bacteria recognize human blood-related proteins. Antibodies against SARS-CoV-2 and adenovirus recognized vWF, PDE and PF4 and SARS-CoV-2 antibodies also recognized additional antigens. Most bacterial antibodies tested (group A streptococci [GAS], staphylococci, Escherichia coli [E. coli], Klebsiella pneumoniae, Clostridia, and Mycobacterium tuberculosis) cross-reacted with CL and PF4. while GAS antibodies also bound to F2, Factor VIII, Factor IX, and vWF, and E. coli antibodies to PDE. All cross-reactive interactions involved antibody-antigen binding constants smaller than 100 nM. Since most COVID-19 coagulopathy patients display autoantibodies against vWF, PDE and PF4 along with CL, combinations of viral and bacterial infections appear to be necessary to initiate their autoimmune coagulopathies.

Does Influenza Vaccination Reduce the Risk of Contracting COVID-19?

The concurrent timing of the COVID-19 pandemic and the seasonal occurrence of influenza, makes it especially important to analyze the possible effect of the influenza vaccine on the risk of contracting COVID-19, or in reducing the complications caused by both diseases, especially in vulnerable populations. There is very little scientific information on the possible protective role of the influenza vaccine against the risk of contracting COVID-19, particularly in groups at high-risk of influenza complications. Reducing the risk of contracting COVID-19 in high-risk patients (those with a higher risk of infection, complications, and death) is essential to improve public well-being and to reduce hospital pressure and the collapse of primary health centers. Apart from overlapping in time, COVID-19 and flu share common aspects of transmission, so that measures to protect against flu might be effective in reducing the risk of contracting COVID-19. In this study, we conclude that the risk of contracting COVID-19 is reduced if patients are vaccinated against flu, but the reduction is small (0.22%) and therefore not clinically important. When this reduction is analysed based on the risk factor suffered by the patient, statistically significant differences have been obtained for patients with cardiovascular problems, diabetics, chronic lung and chronic kidney disease; in all four cases the reduction in the risk of contagion does not reach 1%. It is worth highlighting the behaviour that is completely different from the rest of the data for institutionalized patients. The data for these patients does not suggest a reduction in the risk of contagion for patients vaccinated against the flu, but rather the opposite, a significant increase of 6%. Socioeconomic conditions, as measured by the MEDEA deprivation index, explain increases in the risk of contracting COVID-19, and awareness campaigns should be increased to boost vaccination programs.

The Association Between Previous Influenza Vaccination and COVID-19 Infection Risk and Severity: A Systematic Review and Meta-analysis

INTRODUCTION

The association between influenza vaccination and COVID-19 remains controversial. This meta-analysis aimed to investigate whether influenza vaccination reduces the susceptibility and severity of SARS-CoV-2 infection.

METHODS

A systematic literature search of PubMed, Web of Science, the Cochrane Library, Embase, China National Knowledge Infrastructure, SinoMed, Wanfang Data Knowledge Service Platform, and China Science and Technology Journal VIP Database was conducted from database inception to August 2021. The pooled RR with 95% CI was used to estimate the effect of influenza vaccination on COVID-19. The I² value was used to assess heterogeneity. If I²>50%, the random-effects model was used as the pooling method.

RESULTS

A total of 23 published articles with 1,037,445 participants were identified. This meta-analysis showed that influenza vaccination was associated with reduced risk of COVID-19 infection (RR=0.83, 95% CI=0.76, 0.90) and hospitalization (RR=0.71, 95% CI=0.59, 0.84), although not significantly associated with intensive care unit admission and death (risk of intensive care unit admission: RR=0.93, 95% CI=0.64, 1.36; risk of death: RR=0.83, 95% CI=0.68, 1.01). Further analysis suggested that the tetravalent influenza vaccine may be associated with a reduced risk of COVID-19 infection (RR=0.74, 95% CI=0.65, 0.84).

DISCUSSION

The results suggest that influenza vaccination is associated with reduced susceptibility to or disease severity of COVID-19 and that influenza vaccination may reduce the risk of COVID-19 and improve clinical outcomes.

Influenza Vaccination and COVID-19 Outcomes in People Older than 50 Years: Data from the Observational Longitudinal SHARE Study

Existing literature on the association between influenza vaccination and COVID-19 infection/outcomes is conflicting. Therefore, we aimed to investigate the association between influenza vaccination and COVID-19 outcomes in a large cohort of adults who participated in the SHARE (Survey of Health, Ageing, and Retirement in Europe). Information regarding influenza vaccination in the previous year, and medical and demographic characteristics, were self-reported. Positivity for COVID-19, symptomatology, and hospitalization were also ascertained using self-reported information. An adjusted logistic regression analysis (including 15 baseline factors or propensity score) was used to assess the association between influenza vaccination and COVID-19 outcomes. A total of 48,408 participants (mean age 67 years; 54.1% females) were included. The prevalence of influenza vaccination was 38.3%. After adjusting for 15 potential confounders, influenza vaccination was significantly associated with a lower risk of positivity for COVID-19 (OR = 0.95; p < 0.0001), symptomatic forms (OR = 0.87; p < 0.0001), and hospitalization for COVID-19 (OR = 0.95; p < 0.0001). The results were similar when using a propensity score approach. In conclusion, influenza vaccination may be beneficial for the prevention of COVID-19, as the present study found that influenza vaccination was associated with a small/moderate lower risk of COVID-19 infection and adverse outcomes.

An Independent Study to Compare Compliance, Attitudes, Knowledge, and Sources of Knowledge about Pneumococcal Vaccinations among an Italian Sample of Older Adults

Background: Streptococcus pneumoniae is one of the leading causes of pneumoniae deaths, especially among elderly individuals, with the vaccine being the primary prevention instrument. However, information on national vaccine coverage among the elderly population is scarce and sparse. Methods: A survey involved a representative sample of Italians older than 65 years (n = 600), who agreed to participate in the study through a phone interview. Participants’ self-reported pneumococcal vaccination status, vaccine literacy, information source, and risk perception related to the infection and to vaccines-adverse reactions were assessed. Results: The reported vaccination status is very low (11.2%), with respondents largely uninformed about vaccination opportunities. The results also show that the predominant (and most effective) source of information is healthcare providers, with vaccine hesitancy being positively linked to risk perception related to disease and negatively linked to risk perception of vaccine adverse reactions. Conclusions: This study suggests the need to collect data to systematically monitor vaccination coverage and calls for information campaigns to improve elderly literacy to increase vaccination uptake.

Influenza Vaccination Uptake in the General Italian Population during the 2020–2021 Flu Season: Data from the EPICOVID-19 Online Web-Based Survey

To assess influenza vaccine uptake during the 2020/2021 flu season and compare it with that of the 2019/2020 flu season among respondents to the second phase of the web-based EPICOVID-19 survey, we performed an observational web-based nationwide online survey (January–February 2021) in which respondents to the first survey (April–June 2020) were contacted and asked to complete a second questionnaire. Factors associated with vaccine uptake in the 2020/2021 flu season were assessed by applying a multivariable multinomial logistic regression model. Out of the 198,822 respondents to the first survey, 41,473 (20.9%) agreed to fill out the follow-up questionnaire; of these, 8339 (20.1%) were vaccinated only during the 2020/2021 season, 8828 (21.3%) were vaccinated during both seasons and 22,710 (54.8%) were vaccinated in neither season. Educational level (medium (aOR 1.33 95%CI 1.13–1.56) and high (aOR 1.69 95%CI 1.44–1.97) vs. low) and socio-economic deprivation according to SES scoring (1 point aOR 0.83 (95%CI 0.78–0.89), 2 aOR 0.68 (95%CI 0.60–0.77) points or ≥3 points aOR 0.42 (95%CI 0.28–0.45) vs. 0 points) were found to be associated with flu vaccine uptake. Our study shows that social determinants seemed to affect flu vaccination uptake and identifies specific categories of the population to target during future influenza vaccination campaigns.

The Influenza Vaccine May Protect Pregnant and Postpartum Women against Severe COVID-19

The SARS-CoV-2 pandemic has imposed a huge challenge on the antenatal care of pregnant women worldwide, with the maternal mortality rate being raised to alarming levels. While COVID-19 vaccines were developed, some studies highlighted a possible relationship between influenza vaccination and lower odds of COVID-19 infection. As obstetric patients belong to a high-risk group for respiratory diseases, this study evaluated whether influenza vaccination reduces the severity of COVID-19 infection and mortality among pregnant and postpartum women. We conducted a retrospective cohort study on 3370 pregnant and postpartum women from the Brazilian national database, where they were grouped according to their influenza vaccination status before the onset of COVID-19 symptoms. The intensive care unit admission and intubation rates were significantly higher among subjects in the unvaccinated group (p = 0.002 and p < 0.001, respectively). The odds of mortality risk among those who received the vaccine was 0.33, with a 95% confidence interval of 0.23–0.47. The numbers of patients who needed to be vaccinated to avoid a case of intensive care unit admission, intubation, or death due to COVID-19 were 11, 15, and 11, respectively. Influenza vaccines could confer protection against severe COVID-19 infection in pregnant and postpartum women.

Epidemiology of SARS-CoV-2 Infection in Italy Using Real-World Data: Methodology and Cohort Description of the Second Phase of Web-Based EPICOVID19 Study

Digital technologies have been extensively employed in response to the SARS-CoV-2 pandemic worldwide. This study describes the methodology of the two-phase internet-based EPICOVID19 survey, and the characteristics of the adult volunteer respondents who lived in Italy during the first (April-May 2020) and the second wave (January-February 2021) of the epidemic. Validated scales and ad hoc questionnaires were used to collect socio-demographic, medical and behavioural characteristics, as well as information on COVID-19. Among those who provided email addresses during phase I (105,355), 41,473 participated in phase II (mean age 50.7 years ± 13.5 SD, 60.6% females). After a median follow-up of ten months, 52.8% had undergone nasopharyngeal swab (NPS) testing and 13.2% had a positive result. More than 40% had undergone serological test (ST) and 11.9% were positive. Out of the 2073 participants with at least one positive ST, 72.8% had only negative results from NPS or never performed it. These results indicate that a large fraction of individuals remained undiagnosed, possibly contributing to the spread of the virus in the community. Participatory online surveys offer a unique opportunity to collect relevant data at individual level from large samples during confinement.

Heterologous vaccination interventions to reduce pandemic morbidity and mortality: Modeling the US winter 2020 COVID-19 wave

COVID-19 remains a stark health threat worldwide, in part because of minimal levels of targeted vaccination outside high-income countries and highly transmissible variants causing infection in vaccinated individuals. Decades of theoretical and experimental data suggest that nonspecific effects of non-COVID-19 vaccines may help bolster population immunological resilience to new pathogens. These routine vaccinations can stimulate heterologous cross-protective effects, which modulate nontargeted infections. For example, immunization with Bacillus Calmette-Guérin, inactivated influenza vaccine, oral polio vaccine, and other vaccines have been associated with some protection from SARS-CoV-2 infection and amelioration of COVID-19 disease. If heterologous vaccine interventions (HVIs) are to be seriously considered by policy makers as bridging or boosting interventions in pandemic settings to augment nonpharmaceutical interventions and specific vaccination efforts, evidence is needed to determine their optimal implementation. Using the COVID-19 International Modeling Consortium mathematical model, we show that logistically realistic HVIs with low (5 to 15%) effectiveness could have reduced COVID-19 cases, hospitalization, and mortality in the United States fall/winter 2020 wave. Similar to other mass drug administration campaigns (e.g., for malaria), HVI impact is highly dependent on both age targeting and intervention timing in relation to incidence, with maximal benefit accruing from implementation across the widest age cohort when the pandemic reproduction number is >1.0. Optimal HVI logistics therefore differ from optimal rollout parameters for specific COVID-19 immunizations. These results may be generalizable beyond COVID-19 and the US to indicate how even minimally effective heterologous immunization campaigns could reduce the burden of future viral pandemics.

Effect of influenza vaccination on risk of COVID-19 - A prospective cohort study of 46,000 health care workers

The purpose of this study was to assess if influenza vaccination has an impact on the risk of COVID-19. A cohort of 46,112 health care workers were tested for antibodies against SARS-CoV-2 and filled in a survey on COVID-19 symptoms, hospitalization, and influenza vaccination. The RR of hospitalization due to SARS-CoV-2 for influenza vaccinated compared with unvaccinated participants was 1.00 for the seasonal vaccination in 2019/2020 (CI 0.56-1.78, p=1.00). Likewise, no clinical effect of influenza vaccination on development of antibodies against SARS-CoV-2 was found. The present findings indicate that influenza vaccination does not affect the risk of SARS-CoV-2 infection or COVID-19.

COVID-19 coagulopathies: Human blood proteins mimic SARS-CoV-2 virus, vaccine proteins and bacterial co-infections inducing autoimmunity: Combinations of bacteria and SARS-CoV-2 synergize to induce autoantibodies targeting cardiolipin, cardiolipin-binding proteins, platelet factor 4, prothrombin, and coagulation factors

Severe COVID-19 is often accompanied by coagulopathies such as thrombocytopenia and abnormal clotting. Rarely, such complications follow SARS-CoV-2 vaccination. The cause of these coagulopathies is unknown. It is hypothesized that coagulopathies accompanying SARS-CoV-2 infections and vaccinations result from bacterial co-infections that synergize with virus-induced autoimmunity due to antigenic mimicry of blood proteins by both bacterial and viral antigens. Coagulopathies occur mainly in severe COVID-19 characterized by bacterial co-infections with Streptococci, Staphylococci, Klebsiella, Escherichia coli, and Acinetobacter baumannii. These bacteria express unusually large numbers of antigens mimicking human blood antigens, as do both SARS-CoV-2 and adenoviruses. Bacteria mimic cardiolipin, prothrombin, albumin, and platelet factor 4 (PF4). SARS-CoV-2 mimics complement factors, Rh antigens, platelet phosphodiesterases, Factors IX and X, von Willebrand Factor (VWF), and VWF protease ADAMTS13. Adenoviruses mimic prothrombin and platelet factor 4. Bacterial prophylaxis, avoidance of vaccinating bacterially infected individuals, and antigen deletion for vaccines may reduce coagulopathy risk. Also see the video abstract here: https://youtu.be/zWDOsghrPg8.

The Effect of Influenza Vaccination on COVID-19 Morbidity, Severity and Mortality: Systematic Review and Meta-Analysis

Coronavirus disease 2019 (COVID-19) pandemic is rapidly developing worldwide with a high mortality rate. In this meta-analysis study, the effect of influenza vaccination on the prevention of COVID-19 and its consequences in patients were investigated. The systematic search for this study was performed from November 2019 to 25 November 2020, in the databases of Medline, PubMed, Scopus, Web of Science, Embase, Ebsco, Cochrane and medRxiv. Search terms used included COVID-19, coronavirus, SARS-CoV-2, covid, influenza, flu, grippe and vaccine. The present study examined the association between influenza vaccination and COVID-19 including COVID-19 infection, mortality, hospitalisation and intensive care unit (ICU) admission. Finally, the pooled estimates for different outcomes were calculated by the software for statistics and data science (STATA) version 15 and I2 was used to determine the heterogeneity. By analysing the data of articles, the pooled estimates of these data indicated that influenza vaccination could lower probability of COVID-19 infection up to 24% (OR = 0.77; 95% CI: 0.65, 0.91), of death up to 32% (OR = 0.68; 95% CI: 0.42, 1.11), of the hospitalisation up to 25% (OR = 0.75; 95% CI: 0.46; 1.23) and of admission to ICU up to 29% (OR = 0.71; 95% CI: 0.40, 1.27). Influenza vaccination can help decrease the COVID-19 infection and reduce hospitalisation and the need for ICU and mortality rates.

Utilization of drugs with reports on potential efficacy or harm on COVID-19 before, during, and after the first pandemic wave

PURPOSE

Conflicting information on potential benefits of drugs as well as reports on hypothetical harm of commonly used drugs in COVID-19 treatment have challenged clinicians and healthcare systems. We analyzed the change in ambulatory drug utilization before, during, and after the first wave of the pandemic in 2020.

METHODS

We explored dispensing data of nearly 19 000 pharmacies at the expense of the statutory health insurance funds covering 88% of Germany's population. We analyzed utilization of publicly discussed drugs with conflicting information. Drug utilization as number of packages dispensed per week from January to June 2020, reflecting 314 million claims, was compared with 2019.

RESULTS

Utilization of hydroxychloroquine increased +110% during March 2020 and then slightly decreased until week April 13-19. Renin-angiotensin-aldosterone system inhibitors and simvastatin/atorvastatin increased, +78% and +74%, respectively, and subsequently decreased below 2019 levels. Utilization of azithromycin and all systemic antibiotics decreased continuously from March 2-8 until June to levels considerably lower compared to 2019 (June 22-28: azithromycin: -55%, all systemic antibiotics: -27%). Pneumococcal vaccines utilization initially increased +373%, followed by supply shortages. Paracetamol utilization showed an initial increase of +111%, mainly caused by an increase of over-the-counter dispensings.

CONCLUSIONS

Apart from the pandemic itself, the data suggest that dissemination of misinformation and unsound speculations as well as supply shortages influenced drug prescribing, utilization, and purchasing behavior. The findings can inform post-pandemic policy to prevent unfounded over- and underprescribing and off-label use as well as drug shortages during a public health crisis.

Protecting adults at risk of pneumococcal infection and influenza from exposure to SARS-CoV-2

There is a paucity of evidence linking pneumococcal infection and influenza with SARS-CoV-2 and COVID-19. There is circumstantial evidence of the possibility of an association between S. pneumoniae and SARS-CoV-2 such as the increased binding of S. pneumoniae to coronavirus-infected human airway epithelium, the frequent use of broad-spectrum antibiotics in the management of COVID-19 which could mask secondary bacterial infection, and the observation that pneumococcal vaccination is associated with decreased SARS-CoV-2 nasopharyngeal swab positivity. We performed a targeted literature review for the year 2020, using search terms S. pneumoniae, influenza, SARS-CoV-2, and found 25 relevant articles of a total of 291. Pneumococcal and influenza vaccinations have the potential to contribute toward efforts aimed at reducing the health burden of SARS-CoV-2, especially by reducing preventable admissions to hospital for pneumonia and the consequent risk of nosocomial SARS-CoV-2 transmission.

Natural killer-cell immunoglobulin-like receptors trigger differences in immune response to SARS-CoV-2 infection

Background

The diversity in the clinical course of COVID-19 has been related to differences in innate and adaptative immune response mechanisms. Natural killer (NK) lymphocytes are critical protagonists of human host defense against viral infections. It would seem that reduced circulating levels of these cells have an impact on COVID-19 progression and severity. Their activity is strongly regulated by killer-cell immuno-globulin-like receptors (KIRs) expressed on the NK cell surface. The present study’s focus was to investigate the impact of KIRs and their HLA Class I ligands on SARS-CoV-2 infection.

Methods

KIR gene frequencies, KIR haplotypes, KIR ligands and combinations of KIRs and their HLA Class I ligands were investigated in 396 Sardinian patients with SARS-CoV-2 infection. Comparisons were made between 2 groups of patients divided according to disease severity: 240 patients were symptomatic or paucisymptomatic (Group A), 156 hospitalized patients had severe disease (Group S). The immunogenetic characteristics of patients were also compared to a population group of 400 individuals from the same geographical areas.

Results

Substantial differences were obtained for KIR genes, KIR haplotypes and KIR-HLA ligand combinations when comparing patients of Group S to those of Group A. Patients in Group S had a statistically significant higher frequency of the KIR A/A haplotype compared to patients in Group A [34.6% vs 23.8%, OR = 1.7 (95% CI 1.1–2.6); P = 0.02, Pc = 0.04]. Moreover, the KIR2DS2/HLA C1 combination was poorly represented in the group of patients with severe symptoms compared to those of the asymptomatic-paucisymptomatic group [33.3% vs 50.0%, OR = 0.5 (95% CI 0.3–0.8), P = 0.001, Pc = 0.002]. Multivariate analysis confirmed that, regardless of the sex and age of the patients, the latter genetic variable correlated with a less severe disease course [OR_M = 0.4 (95% CI 0.3–0.7), P_M = 0.0005, P_MC = 0.005].

Conclusions

The KIR2DS2/HLA C1 functional unit resulted to have a strong protective effect against the adverse outcomes of COVID-19. Combined to other well known factors such as advanced age, male sex and concomitant autoimmune diseases, this marker could prove to be highly informative of the disease course and thus enable the timely intervention needed to reduce the mortality associated with the severe forms of SARS-CoV-2 infection. However, larger studies in other populations as well as experimental functional studies will be needed to confirm our findings and further pursue the effect of KIR receptors on NK cell immune-mediated response to SARS-Cov-2 infection.

[Vaccination against community acquired pneumonia in adults. Update 2021 of the position paper by Neumoexpertos en Prevención Group]

Community-acquired pneumonia (CAP) continues to be an important cause of morbidity and mortality in adults. The aim of this study is to update the practical prevention guide for CAP through vaccination in Spain developed in 2016 and updated in 2018, based on available vaccines and evidence through bibliographic review and expert opinion. The arrival of COVID-19 as a new cause of CAP and the recent availability of safe and effective vaccines constitutes the most significant change. Vaccines against pneumococcus, influenza, pertussis and COVID-19 can help to reduce the burden of disease from CAP and its associated complications. The available evidence supports the priority indications established in this guide, and it would be advisable to try to achieve a widespread dissemination and implementation of these recommendations in routine clinical practice.

Vaccination as a preventative measure contributing to immune fitness

The primary goal of vaccination is the prevention of pathogen-specific infection. The indirect consequences may include maintenance of homeostasis through prevention of infection-induced complications; trained immunity that re-programs innate cells to respond more efficiently to later, unrelated threats; slowing or reversing immune senescence by altering the epigenetic clock, and leveraging the pool of memory B and T cells to improve responses to new infections. Vaccines may exploit the plasticity of the immune system to drive longer-term immune responses that promote health at a broader level than just the prevention of single, specific infections. In this perspective, we discuss the concept of “immune fitness” and how to potentially build a resilient immune system that could contribute to better health. We argue that vaccines may contribute positively to immune fitness in ways that are only beginning to be understood, and that life-course vaccination is a fundamental tool for achieving healthy aging.

SARS-CoV-2 serology in 4000 health care and administrative staff across seven sites in Lombardy, Italy

Lombardy is the Italian region most affected by COVID-19. We tested the presence of plasma anti-SARS-CoV-2 IgG antibodies in 3985 employees across 7 healthcare facilities in areas of Lombardy with different exposure to the SARS-CoV-2 epidemic. Subjects filled a questionnaire to self-report on COVID-19 symptoms, comorbidities, smoking, regular or remote working, and the exposure to COVID-infected individuals. We show that the number of individuals exposed to the virus depended on the geographical location of the facility, ranging between 3 and 43%, consistent with the spatial variation of COVID-19 incidence in Lombardy, and correlated with family interactions. We observed a higher prevalence of females than males positive for IgG, however the level of antibodies was similar, suggesting a comparable magnitude of the anti-spike antibody response. IgG positivity among smokers was lower (7.4% vs 13.5%) although without difference in IgG plasma levels. We observed 11.9% of IgG positive asymptomatic individuals and another 23.1% with one or two symptoms. Interestingly, among the IgG positive population, 81.2% of subjects with anosmia/dysgeusia and fever were SARS-CoV-2 infected, indicating that these symptoms are strongly associated to COVID-19. In conclusion, the frequency of IgG positivity and SARS-CoV-2 infection is dependent on the geographical exposure to the virus and primarily to family rather than hospital exposure.

Upper Respiratory Tract Co-detection of Human Endemic Coronaviruses and High-density Pneumococcus Associated With Increased Severity Among HIV-Uninfected Children Under 5 Years Old in the PERCH Study

BACKGROUND

Severity of viral respiratory illnesses can be increased with bacterial coinfection and can vary by sex, but influence of coinfection and sex on human endemic coronavirus (CoV) species, which generally cause mild to moderate respiratory illness, is unknown. We evaluated CoV and pneumococcal co-detection by sex in childhood pneumonia.

METHODS

In the 2011-2014 Pneumonia Etiology Research for Child Health study, nasopharyngeal and oropharyngeal (NP/OP) swabs and other samples were collected from 3981 children <5 years hospitalized with severe or very severe pneumonia in 7 countries. Severity by NP/OP detection status of CoV (NL63, 229E, OC43 or HKU1) and high-density (≥6.9 log10 copies/mL) pneumococcus (HDSpn) by real-time polymerase chain reaction was assessed by sex using logistic regression adjusted for age and site.

RESULTS

There were 43 (1.1%) CoV+/HDSpn+, 247 CoV+/HDSpn-, 449 CoV-/HDSpn+ and 3149 CoV-/HDSpn- cases with no significant difference in co-detection frequency by sex (range 51.2%-64.0% male, P = 0.06). More CoV+/HDSpn+ pneumonia was very severe compared with other groups for both males (13/22, 59.1% versus range 29.1%-34.7%, P = 0.04) and females (10/21, 47.6% versus 32.5%-43.5%, P = 0.009), but only male CoV+/HDSpn+ required supplemental oxygen more frequently (45.0% versus 20.6%-28.6%, P < 0.001) and had higher mortality (35.0% versus 5.3%-7.1%, P = 0.004) than other groups. For females with CoV+/HDSpn+, supplemental oxygen was 25.0% versus 24.8%-33.3% (P = 0.58) and mortality was 10.0% versus 9.2%-12.9% (P = 0.69).

CONCLUSIONS

Co-detection of endemic CoV and HDSpn was rare in children hospitalized with pneumonia, but associated with higher severity and mortality in males. Findings may warrant investigation of differences in severity by sex with co-detection of HDSpn and SARS-CoV-2.

Influenza vaccination and the risk of COVID-19 infection and severe illness in older adults in the United States

The coronavirus disease of 2019 (COVID-19) has caused a global pandemic and led to nearly three million deaths globally. As of April 2021, there are still many countries that do not have COVID-19 vaccines. Before the COVID-19 vaccines were developed, some evidence suggested that an influenza vaccine may stimulate nonspecific immune responses that reduce the risk of COVID-19 infection or the severity of COVID-19 illness after infection. This study evaluated the association between influenza vaccination and the risk of COVID-19 infection. We conducted a retrospective cross-sectional study with data from July 1, 2019, to June 30, 2020 with the Claims data from Symphony Health database. The study population was adults age 65 years old or older who received influenza vaccination between September 1 and December 31 of 2019. The main outcomes and measures were odds of COVID-19 infection and severe COVID-19 illness after January 15, 2020. We found the adjusted odds ratio (aOR) of COVID-19 infection risk between the influenza-vaccination group and no-influenza-vaccination group was 0.76 (95% confidence interval (CI), 0.75-0.77). Among COVID-19 patients, the aOR of developing severe COVID-19 illness was 0.72 (95% CI, 0.68-0.76) between the influenza-vaccination group and the no-influenza-vaccination group. When the influenza-vaccination group and the other-vaccination group were compared, the aOR of COVID-19 infection was 0.95 (95% CI, 0.93-0.97), and the aOR of developing a severe COVID-19 illness was 0.95 (95% CI, 0.80-1.13). The influenza vaccine may marginally protect people from COVID-19 infection.

The Association between Influenza Vaccination and COVID-19 and Its Outcomes: A Systematic Review and Meta-Analysis of Observational Studies

Influenza could circulate in parallel with COVID-19. In the context of COVID-19, some studies observed inverse associations between influenza vaccination and SARS-CoV-2 infection and clinical outcomes, while others did not. We conducted a meta-analysis to assess the association between influenza vaccination and SARS-CoV-2 infection and clinical outcomes, aiming to provide evidence for COVID-19 prevention and vaccination promotion. We searched four databases from inception to 10 March, 2021. Random effects and fixed effects models were used to pool odds ratios (ORs) and adjusted estimates with 95% confidence intervals (CIs). We used funnel plots to evaluate the publication bias, I2 statistics to evaluate the heterogeneity, and conducted subgroup analyses. Sixteen observational studies involving 290,327 participants were included. Influenza vaccination was associated with a lower risk of SARS-CoV-2 infection (pooled adjusted OR: 0.86, 95%CI: 0.81–0.91), while not significantly associated with adverse outcomes (intensive care: adjusted OR 0.63, 95%CI: 0.22–1.81; hospitalization: adjusted OR 0.74, 95%CI: 0.51–1.06; mortality: adjusted OR 0.89, 95%CI: 0.73–1.09). Our findings suggest that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection. It is crucial for policy makers to implement strategies on influenza vaccination, for it may also have benefits for COVID-19 prevention.

The effect of seasonal influenza vaccine on medically-attended influenza and non-influenza respiratory viruses infections at primary care level, Hong Kong SAR, 2017/18 to 2019/20

Effectiveness of seasonal influenza vaccine (SIV) varies with the degree of matching with the vaccine and circulating viruses. We continued our SIV effectiveness against medically-attended influenza-like illness (ILI) under the Department of Health Hong Kong's sentinel private medical practitioners (PMP) network, using the test-negative case-control design, for the 2018/19 and 2019/20 season. In addition, we studied the potential interference between SIV and ILI caused by non-influenza respiratory viruses (NIRV) based on data collated from 2017/18 to 2019/20 seasons. 3404 patients were analysed. Across the 2017/18 to 2019/20 seasons, the vaccine effectiveness (VE) of SIV was 44% (95% CI 30-56%) against pan-negative controls, 57% (95%CI. 42-68%) against NIRV controls and 50% (95%CI 38-59%) against both. SIV was moderately effective against medically-attended ILI caused by influenza A/B in both 2018/19 and 2019/20 winter seasons (53.2% (95%CI 36.7-65.5%) and 41.8% (95%CI 6.3-64.1%), respectively). The VE against the main circulating subtype, influenza A(H1), was higher for the 2018/19 season (57.2% (95%CI 39.8-69.9%), compared to 34.6% (95%CI -9.6-61.4%) in the 2019/20 season). When compared to pan negative controls, those with single NIRV infections were similarly likely to have received SIV (OR 1.05 (95%CI 0.72-1.54) within the influenza season; OR 0.97 (95%CI 0.73-1.29) when including non-influenza seasons). Analyses by type of virus showed no increased risk of SIV identified among those with single infections of EV/RV, HMPV and parainfluenza but a 2-fold increased risk was shown for those with single infections of adenovirus and parainfluenza virus (adenovirus: OR 2.54 (95%CI 1.24-5.14) within influenza season and OR 1.78 (95%CI 1.01-3.09) for the whole period; parainfluenza virus: OR 2.01 (95%CI 1.22-3.29) within influenza season and OR 1.89 (95%CI 1.29-2.76) for the whole period). SIV programme and surveillance of influenza and NIRV, including SARS-CoV-2, should continue during the COVID-19 pandemic.

Influenza and pneumococcal vaccinations are not associated to COVID-19 outcomes among patients admitted to a university hospital

In order to reduce the burden on healthcare systems and to support differential diagnosis with COVID-19, influenza and pneumococcal vaccinations were strongly recommended during the COVID-19 pandemic, especially in vulnerable groups. However, no univocal and conclusive evidence on the relationship between influenza and pneumococcal vaccinations and COVID‐19 outcomes exists. We evaluated the association between such vaccinations, COVID-19 hospitalization, intensive care unit admissions and deaths in a cohort (N = 741) of COVID-19 patients who had access to the emergency room of a large Italian University hospital between March 1, 2020 and June 1, 2020. Results show that influenza and pneumococcal vaccinations did not affect hospitalization, intensive care unit admission and deaths in COVID-19 patients in the overall sample and in those ≥65 years. The same pattern of results was confirmed considering timing of influenza vaccine administration, vaccination type, and number of uptakes in the last five vaccination campaigns. In conclusion, our study does not support an impact of influenza and pneumococcal vaccinations on COVID-19 outcomes.

Pneumococcal and Influenza Vaccination Rates and Pneumococcal Invasive Disease Rates Set Geographical and Ethnic Population Susceptibility to Serious COVID-19 Cases and Deaths

This study examines the relationship of pneumococcal vaccination rates, influenza, measles-mumps-rubella (MMR) diphtheria-tetanus-pertussis vaccinations (DTP), polio, Haemophilus influenzae type B (Hib), and Bacillus Calmette-Guerin (tuberculosis) vaccination rates to COVID-19 case and death rates for 51 nations that have high rates of COVID-19 testing and for which nearly complete childhood, at-risk adult and elderly pneumococcal vaccination data were available. The study is unique in a large number of nations examined, the range of vaccine controls, in testing effects of combinations of vaccinations, and in examining the relationship of COVID-19 and vaccination rates to invasive pneumococcal disease (IPD). Analysis of Italian regions and the states of the United States were also performed. Significant positive correlations were found between IPD (but not lower respiratory infections) and COVID-19 rates, while significant negative correlations were found between pneumococcal vaccination and COVID-19 rates. Influenza and MMR vaccination rates were negatively correlated with lower respiratory infection (LRI) rates and may synergize with pneumococcal vaccination rates to protect against COVID-19. Pneumococcal and influenza vaccination rates were independent of other vaccination rates. These results suggest that endemic rates of bacterial pneumonias, for which pneumococci are a sentinel, may set regional and national susceptibility to severe COVID-19 disease and death.

Impact of influenza vaccination on the risk of SARS-CoV-2 infection in a middle-aged group of people

Aims: An observational study of a retrospective cohort was performed to assess the impact of influenza vaccination (IV) on the risk of SARS-CoV-2 infection in a population of middle-aged people for 8 weeks after IV and compared with an unvaccinated group.

Patients and methods: Data from 1098 middle-aged patients (53.7 ± 4.7 years) after IV and 1205 unvaccinated patients (50.1 ± 6.8 years) were analyzed based on medical documentation. The inclusion criteria were age between 40 − 60 years and IV in the period from 1−30 September 2020. The incidence of infection with SARS-CoV-2 was confirmed by PCR and the classification of ICD-10 (U07.1).

Results and conclusions: After IV, patients had significantly fewer SARS-CoV–2 infections than the unvaccinated patients (P = .017). The hazard ratio was 0.74 (95% CI: 0.54−0.89). IV may partially reduce the risk of SARS-CoV-2 infection.

Association Between Smoking and SARS-CoV-2 Infection: Cross-sectional Study of the EPICOVID19 Internet-Based Survey

Background

Several studies have reported a low prevalence of current smoking among hospitalized COVID-19 cases; however, no definitive conclusions can be drawn.

Objective

We investigated the association of tobacco smoke exposure with nasopharyngeal swab (NPS) test results for SARS-CoV-2 infection and disease severity accounting for possible confounders.

Methods

The nationwide, self-administered, cross-sectional web-based Italian National Epidemiological Survey on COVID-19 (EPICOVID19) was administered to an Italian population of 198,822 adult volunteers who filled in an online questionnaire between April 13 and June 2, 2020. For this study, we analyzed 6857 individuals with known NPS test results. The associations of smoking status and the dose-response relationship with a positive NPS test result and infection severity were calculated as odds ratios (ORs) with 95% CIs by means of logistic and multinomial regression models adjusting for sociodemographic, clinical, and behavioral characteristics.

Results

Out of the 6857 individuals (mean age 47.9 years, SD 14.1; 4516/6857, 65.9% female), 63.2% (4334/6857) had never smoked, 21.3% (1463/6857) were former smokers, and 15.5% (1060/6857) were current smokers. Compared to nonsmokers, current smokers were younger, were more educated, were less affected by chronic diseases, reported COVID-19–like symptoms less frequently, were less frequently hospitalized, and less frequently tested positive for COVID-19. In multivariate analysis, current smokers had almost half the odds of a positive NPS test result (OR 0.54, 95% CI 0.45-0.65) compared to nonsmokers. We also found a dose-dependent relationship with tobacco smoke: mild smokers (adjusted OR [aOR] 0.76, 95% CI 0.55-1.05), moderate smokers (aOR 0.56, 95% CI 0.42-0.73), and heavy smokers (aOR 0.38, 95% CI 0.27-0.53). This inverse association also persisted when considering the severity of the infection. Current smokers had a statistically significantly lower probability of having asymptomatic (aOR 0.50, 95% CI 0.27-0.92), mild (aOR 0.65, 95% CI 0.53-0.81), and severe infections (aOR 0.27, 95% CI 0.17-0.42) compared to those who never smoked.

Conclusions

Current smoking was negatively associated with SARS-CoV-2 infection with a dose-dependent relationship. Ad hoc experimental studies are needed to elucidate the mechanisms underlying this association.

Trial Registration

ClinicalTrials.gov NCT04471701; https://clinicaltrials.gov/ct2/show/NCT04471701

Influenza Vaccination and COVID-19 Mortality in the USA: An Ecological Study

The COVID-19 mortality rate is higher in the elderly and in those with pre-existing chronic medical conditions. The elderly also suffer from increased morbidity and mortality from seasonal influenza infections; thus, an annual influenza vaccination is recommended for them. In this study, we explore a possible county-level association between influenza vaccination coverage in people aged 65 years and older and the number of deaths from COVID-19. To this end, we used COVID-19 data up to 14 December 2020 and US population health data at the county level. We fit quasi-Poisson regression models using influenza vaccination coverage in the elderly population as the independent variable and the COVID-19 mortality rate as the outcome variable. We adjusted for an array of potential confounders using different propensity score regression methods. Results show that, on the county level, influenza vaccination coverage in the elderly population is negatively associated with mortality from COVID-19, using different methodologies for confounding adjustment. These findings point to the need for studying the relationship between influenza vaccination and COVID-19 mortality at the individual level to investigate any underlying biological mechanisms.

Association between Influenza Vaccination and Positive SARS-CoV-2 IgG and IgM Tests in the General Population of Katowice Region, Poland

The explanation of the potential interaction between the influenza vaccine and SARS-CoV-2 infection is urgently needed in the public health. The objective of the study is to compare the occurrence of positive SARS-CoV-2 IgG and IgM tests in subjects with and without recent (last year) seasonal influenza vaccinations. In a cross-sectional study located in three large towns of Silesian Voivodeship (Poland), we studied 5479 subjects in which 1253 (22.9%) had a positive anti-SARS-CoV-2 IgG test and 400 (7.3%) had a positive anti-SARS-CoV-2 IgM test. Seasonal influenza vaccination remains an independent factor protecting against positive IgG tests (OR = 0.68; 0.55–0.83). The effect is not apparent with IgM antibodies. The obtained results confirmed that the serological status of SARS-CoV-2 infection depends on vaccination against seasonal influenza.

Association between Influenza Vaccination and Positive SARS-CoV-2 IgG and IgM Tests in the General Population of Katowice Region, Poland

The explanation of the potential interaction between the influenza vaccine and SARS-CoV-2 infection is urgently needed in the public health. The objective of the study is to compare the occurrence of positive SARS-CoV-2 IgG and IgM tests in subjects with and without recent (last year) seasonal influenza vaccinations. In a cross-sectional study located in three large towns of Silesian Voivodeship (Poland), we studied 5479 subjects in which 1253 (22.9%) had a positive anti-SARS-CoV-2 IgG test and 400 (7.3%) had a positive anti-SARS-CoV-2 IgM test. Seasonal influenza vaccination remains an independent factor protecting against positive IgG tests (OR = 0.68; 0.55-0.83). The effect is not apparent with IgM antibodies. The obtained results confirmed that the serological status of SARS-CoV-2 infection depends on vaccination against seasonal influenza.

Association between Influenza Vaccination and Positive SARS-CoV-2 IgG and IgM Tests in the General Population of Katowice Region, Poland

The explanation of the potential interaction between the influenza vaccine and SARS-CoV-2 infection is urgently needed in the public health. The objective of the study is to compare the occurrence of positive SARS-CoV-2 IgG and IgM tests in subjects with and without recent (last year) seasonal influenza vaccinations. In a cross-sectional study located in three large towns of Silesian Voivodeship (Poland), we studied 5479 subjects in which 1253 (22.9%) had a positive anti-SARS-CoV-2 IgG test and 400 (7.3%) had a positive anti-SARS-CoV-2 IgM test. Seasonal influenza vaccination remains an independent factor protecting against positive IgG tests (OR = 0.68; 0.55–0.83). The effect is not apparent with IgM antibodies. The obtained results confirmed that the serological status of SARS-CoV-2 infection depends on vaccination against seasonal influenza.

Impact of gender on patients hospitalized for SARS-COV-2 infection: A prospective observational study

Biological sex could affect the natural history of severe acute respiratory syndrome coronavirus 2 infection. We enrolled all COVID‐19 patients admitted to two COVID‐19 hospitals in Milan in a prospective observational study. The primary outcome was death during the study period and the secondary outcome was critical disease at hospital admission. The association(s) between clinically relevant, noncollinear variables, and the primary outcome was assessed with uni‐ and multivariable Logistic regression models. A total of 520 patients were hospitalized of whom 349 (67%) were males with a median age 61 (interquartile range: 50–72). A higher proportion of males presented critically ill when compared to females (30.1% vs. 18.7%, p < .046). Death occurred in 86 (24.6%) males and 27 (15.8%) females (p = .024). In multivariable analysis age (per 10 years more) (adjusted odds ratio [AOR]: 1.83 [95% confidence interval {CI}: 1.42–2.35], p < .0001), obesity (AOR: 2.17 [95% CI: 1.10–4.31], p = .026), critical disease at hospital admission (AOR 6.34 [95% CI: 3.50–11.48], p < .0001) were independently associated to higher odds of death whereas gender was not. In conclusion, a higher proportion of males presented critically ill at hospital admission. Age, critical disease at hospital admission, obesity, anemia, D‐dimer, estimated glomerular filtration rate, lactate dehydrogenase, and creatine kinase predicted death in hospitalized COVID‐19 patients.

Fear of COVID-19 for Individuals and Family Members: Indications from the National Cross-Sectional Study of the EPICOVID19 Web-Based Survey

The study analyzed the association of the fear of contagion for oneself and for family members (FMs) during the first wave of the COVID-19 pandemic, with demographic and socioeconomic status (SES) and health factors. The study was performed within the EPICOVID19 web-based Italian survey, involving adults from April-June 2020. Out of 207,341 respondents, 95.9% completed the questionnaire (60% women with an average age of 47.3 vs. 48.9 years among men). The association between fear and demographic and SES characteristics, contacts with COVID-19 cases, nasopharyngeal swab, self-perceived health, flu vaccination, chronic diseases and specific symptoms was analyzed by logistic regression model; odds ratios adjusted for sex, age, education and occupation were calculated (aORs). Fear for FMs prevailed over fear for oneself and was higher among women than men. Fear for oneself decreased with higher levels of education and in those who perceived good health. Among those vaccinated for the flu, 40.8% responded they had feelings of fear for themselves vs. 34.2% of the not vaccinated. Fear increased when diseases were declared and it was higher when associated with symptoms such as chest pain, olfactory/taste disorders, heart palpitations (aORs > 1.5), lung or kidney diseases, hypertension, depression and/or anxiety. Trends in fear by region showed the highest percentage of positive responses in the southern regions. The knowledge gained from these results should be used to produce tailored messages and shared public health decisions.