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

Letter Endocrinology & Metabolism

Influenza vaccination and prognosis for COVID-19 in hospitalized patients with diabetes: Results from the CORONADO study

Alhassane Diallo et al.

DIABETES OBESITY & METABOLISM (2022)

Article Immunology

Effect of Influenza Vaccination on Risk of Coronavirus Disease 2019: A Prospective Cohort Study of 46 000 Healthcare Workers

Jonas Henrik Kristensen et al.

Summary: This study found that influenza vaccination does not affect the risk of SARS-CoV-2 infection or COVID-19. A cohort of 46,112 healthcare workers were observed through a survey and antibody testing.

JOURNAL OF INFECTIOUS DISEASES (2022)

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Article Immunology

Sequential Delivery of Live Attenuated Influenza Vaccine and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the Ferret Model Can Reduce SARS-CoV-2 Shedding and Does Not Result in Enhanced Lung Pathology

Kathryn A. Ryan et al.

Summary: A study found that administration of live attenuated influenza vaccine (LAIV) in proximity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection does not exacerbate mild coronavirus disease 2019 (COVID-19), and if given before infection, it can reduce SARS-CoV-2 shedding.

JOURNAL OF INFECTIOUS DISEASES (2022)

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Article Immunology

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

Cristiane de Freitas Paganoti et al.

Summary: Influenza vaccination in pregnant and postpartum women may reduce the severity and mortality of COVID-19 infection, with a lower number of patients needed to be vaccinated to prevent severe outcomes.

VACCINES (2022)

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Review Primary Health Care

Can Nutritional Supports Beneficial in Other Viral Diseases Be Favorable for COVID-19?

Fatmanur Zehra Zelka et al.

Summary: The COVID-19 pandemic caused by SARS-COV-2 has resulted in numerous deaths and has prompted global public health organizations and governments to recommend various preventive measures. This review explores the potential of nutrition in preventing and mitigating viral infections, particularly in the context of COVID-19. However, there is a lack of research on the nutritional impact of COVID-19, despite the known benefits of nutritional interventions in treating viral infections.

KOREAN JOURNAL OF FAMILY MEDICINE (2022)

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Review Public, Environmental & Occupational Health

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

Wanying Su et al.

Summary: This meta-analysis found that influenza vaccination is associated with reduced risk of COVID-19 infection and hospitalization. However, it does not significantly affect intensive care unit admission and death. Further analysis suggests that tetravalent influenza vaccine may lower the risk of COVID-19 infection.

AMERICAN JOURNAL OF PREVENTIVE MEDICINE (2022)

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Letter Medicine, General & Internal

SARS-CoV-2 co-infection with influenza viruses, respiratory syncytial virus, or adenoviruses

Maaike C. Swets et al.

LANCET (2022)

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Article Cell Biology

Immunosenescence and COVID-19

Jacek M. Witkowski et al.

Summary: Ageing is associated with changes in immune system function. These changes may contribute to the increased severity and deadliness of COVID-19 in the elderly. Immunosenescence and inflammaging, which develop over time depending on challenges to the immune system, can affect the reactivity to SARS-CoV-2. Infection with SARS-CoV-2 can also impact the function of the immune system. Immunosenescence and inflammaging can worsen, and be worsened by, SARS-CoV-2 infection.

MECHANISMS OF AGEING AND DEVELOPMENT (2022)

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Article Chemistry, Medicinal

COVID-19 and Seasonal Influenza Vaccination: Cross-Protection, Co-Administration, Combination Vaccines, and Hesitancy

Alexander Domnich et al.

Summary: This article comprehensively reviews the available evidence on the co-administration and combination of COVID-19 and influenza vaccines, discussing their safety, immunogenicity, efficacy, policy, and public acceptance. While it is still uncertain whether co-administration or combination vaccines can have additive effects on outcomes, it has been shown to be safe and the immune response in the co-administration groups is generally non-inferior to that seen in groups receiving either vaccine alone.

PHARMACEUTICALS (2022)

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Article Infectious Diseases

Absence of association between 2019-20 influenza vaccination and COVID-19: Results of the European I-MOVE-COVID-19 primary care project, March-August 2020

Esther Kissling et al.

Summary: The study found no evidence of a link between influenza vaccination and COVID-19. People of different age groups who received the flu vaccine had similar chances of contracting COVID-19, suggesting the importance of encouraging flu vaccination. The results of the study provide valuable information for COVID-19 vaccine strategies.

INFLUENZA AND OTHER RESPIRATORY VIRUSES (2021)

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Article Immunology

A Case-Control Study of the 2019 Influenza Vaccine and Incidence of COVID-19 Among Healthcare Workers

Nilofar Massoudi et al.

Summary: The study found that the 2019 influenza vaccine may have a protective association against COVID-19 among healthcare workers, with data showing a lower probability of contracting COVID-19 among individuals who received the influenza vaccine.

JOURNAL OF CLINICAL IMMUNOLOGY (2021)

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Article Biotechnology & Applied Microbiology

The association of previous influenza vaccination and coronavirus disease-2019

Ilan Green et al.

Summary: Studies have shown similarities between influenza and coronaviruses in terms of structure, binding receptors, and immune responses. Influenza vaccine can induce cross-immunity. The research suggests that influenza vaccination could reduce the risk of SARS-CoV-2 infection, making it highly recommended before the influenza season to lessen the burden of influenza outbreaks and their association with reduced rates of COVID-19.

HUMAN VACCINES & IMMUNOTHERAPEUTICS (2021)

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Article Infectious Diseases

Epidemiological, socio-demographic and clinical features of the early phase of the COVID-19 epidemic in Ecuador

Esteban Ortiz-Prado et al.

Summary: This study summarizes the early epidemiological trends of the COVID-19 pandemic in Ecuador, highlighting the higher mortality rates among unemployed individuals and the strong association between poverty and mortality. Important determinants of mortality identified include the presence of comorbidities, male gender, and age above 65. Coastal regions in Ecuador had higher mortality rates compared to highlands.

PLOS NEGLECTED TROPICAL DISEASES (2021)

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Article Public, Environmental & Occupational Health

Impact of the influenza vaccine on COVID-19 infection rates and severity

Anna Conlon et al.

Summary: The study found that patients who received the influenza vaccine were less likely to test positive for COVID-19, and also showed improved clinical outcomes such as reduced hospitalization rates and need for mechanical ventilation.

AMERICAN JOURNAL OF INFECTION CONTROL (2021)

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Article Infectious Diseases

Pneumonia in healthcare workers during a COVID-19 outbreak at a cardiovascular hospitals

Ivan Ilic et al.

Summary: A study on infected healthcare workers at a cardiovascular hospital during the COVID-19 pandemic found that seasonal influenza immunization may be associated with less-severe pneumonia, supporting the implementation of preventive measures to reduce the global burden of COVID-19.

INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES (2021)

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Article Primary Health Care

Influenza Vaccination and Hospitalizations Among COVID-19 Infected Adults

Ming-Jim Yang et al.

Summary: The study found that COVID-19 patients who had not received the influenza vaccine were more likely to be hospitalized and admitted to the intensive care unit. The influenza vaccine may help protect against moderate and severe cases of COVID-19, regardless of comorbidities.

JOURNAL OF THE AMERICAN BOARD OF FAMILY MEDICINE (2021)

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Article Public, Environmental & Occupational Health

Vaccination against seasonal influenza and socio-economic and environmental factors as determinants of the geographic variation of COVID-19 incidence and mortality in the Italian elderly

P. Cocco et al.

Summary: The study suggests that seasonal influenza vaccination may have a positive impact on the spread of COVID-19, with population density and vehicular traffic moderately associated with cumulative incidence. Other variables did not show a significant effect on the incidence, case fatality rate, or mortality from COVID-19.

PREVENTIVE MEDICINE (2021)

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Article Multidisciplinary Sciences

Exploratory analysis of immunization records highlights decreased SARS-CoV-2 rates in individuals with recent non-COVID-19 vaccinations

Colin Pawlowski et al.

Summary: Clinical studies are being conducted to evaluate the potential of existing vaccines in providing protection against SARS-CoV-2 through trained immunity. Analysis of immunization records from 137,037 individuals who underwent SARS-CoV-2 PCR tests revealed associations between various vaccines and decreased infection rates, with a significant reduction among black individuals who received the PCV13 vaccine.

SCIENTIFIC REPORTS (2021)

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Article Public, Environmental & Occupational Health

Association between Influenza Vaccination and severe COVID-19 outcomes at a designated COVID-only hospital in Brooklyn

Ogie Q. Umasabor-Bubu et al.

Summary: Research showed that receiving flu vaccination was associated with a reduced likelihood of ICU admission for severe COVID-19, especially among individuals under 65 years old and non-obese patients. Promoting flu vaccination may help alleviate the strain on critical COVID-19 care until COVID-19 vaccines are widely available.

AMERICAN JOURNAL OF INFECTION CONTROL (2021)

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Article Microbiology

Induction of trained immunity by influenza vaccination-impact on COVID-19

Priya Debisarun et al.

Summary: Influenza vaccination has been shown to reduce the risk of COVID-19 infection by decreasing systemic inflammation and reprogramming immune cells to fight against SARS-CoV-2. This suggests potential benefits of influenza vaccination against COVID-19, calling for future randomized trials to test this possibility.

PLOS PATHOGENS (2021)

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Article Medicine, General & Internal

Effect of influenza vaccine on COVID-19 mortality: a retrospective study

Marcello Candelli et al.

Summary: The study aimed to investigate whether the influenza vaccine could reduce the susceptibility and severity of SARS-CoV-2 infection. It found that COVID-19-positive patients older than 65 years with flu vaccination showed a lower risk of death at 60 days. The study suggests that flu vaccination may reduce the mortality of COVID-19, with prospective studies needed for confirmation.

INTERNAL AND EMERGENCY MEDICINE (2021)

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Article Immunology

Coronavirus Occurrence in the Household Influenza Vaccine Evaluation (HIVE) Cohort of Michigan Households: Reinfection Frequency and Serologic Responses to Seasonal and Severe Acute Respiratory Syndrome Coronaviruses

Joshua G. Petrie et al.

Summary: Reinfection with seasonal HCoVs is frequent, and binding anti-spike protein antibodies do not correlate with protection from seasonal HCoV infection, with little cross-response to SARS-CoV-2 proteins.

JOURNAL OF INFECTIOUS DISEASES (2021)

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Letter Medicine, General & Internal

Ecological fallacy in COVID-19 epidemiological inference: Influenza vaccination rate as an example

Yi-Chu Chen et al.

JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION (2021)

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Article Medicine, General & Internal

Personal and vaccination history as factors associated with SARS-CoV-2 infection

Maria Fernandez-Prada et al.

Summary: The study found that obesity and the use of ARA-2 increase the risk of developing COVID-19, while vaccination with a 13-valent pneumococcal vaccine showed results close to statistical significance.

MEDICINA CLINICA (2021)

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Article Immunology

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

Roberta Pastorino et al.

Summary: Influenza and pneumococcal vaccinations were found to have no impact on COVID-19 outcomes, including hospitalization, intensive care unit admissions, and deaths, during the COVID-19 pandemic. This lack of association was consistent across different factors such as age group, timing of vaccine administration, type of vaccine, and number of vaccine uptakes.

VACCINE (2021)

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Article Immunology

Influenza Vaccination and Health Outcomes in COVID-19 Patients: A Retrospective Cohort Study

Pasquale Domenico Pedote et al.

Summary: This study found no significant association between influenza vaccine and hospitalization or death rates among COVID-19 patients, but male sex, older age, and chronic diseases were identified as risk factors for morbidity and mortality within this group.

VACCINES (2021)

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Article Immunology

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

Malgorzata Kowalska et al.

Summary: This study aimed to compare the occurrence of positive SARS-CoV-2 IgG and IgM tests in subjects with and without recent seasonal influenza vaccinations. It found that seasonal influenza vaccination remains an independent factor protecting against positive IgG tests.

VACCINES (2021)

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Article Immunology

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

Claudio Zanettini et al.

Summary: The study found a negative association between influenza vaccination coverage in the elderly population and mortality from COVID-19 at the county level, indicating the need for further research on the relationship between influenza vaccination and COVID-19 mortality.

VACCINES (2021)

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Article Immunology

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

Robert Root-Bernstein

Summary: This study found a negative correlation between pneumococcal vaccination rates and COVID-19 case and death rates, as well as a significant positive correlation between invasive pneumococcal disease and COVID-19 rates. Additionally, influenza and MMR vaccination rates may synergize with pneumococcal vaccination rates to protect against COVID-19.

VACCINES (2021)

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Article

Asociación entre la vacunación contra influenza y la mortalidad por COVID-19

C.A. Arce-Salinas et al.

Vacunas (2021)

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Article

Is there any effect of flu vaccine on the SARS-CoV-2 infected patients?

D. El-Qutob et al.

Vacunas (2021)

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Article Infectious Diseases

Risk of symptomatic severe acute respiratory syndrome coronavirus 2 infection not associated with influenza vaccination in the 2019-2020 season

Jennifer P. King et al.

Summary: There was no significant association between receiving the influenza vaccine during the 2019-2020 season and the risk of SARS-CoV-2 infection in both adults and children.

INFLUENZA AND OTHER RESPIRATORY VIRUSES (2021)

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Article Medicine, General & Internal

Annual flu shot: Does it help patients with COVID-19?

Adam Kline et al.

Summary: The study found that there were no significant differences in clinical outcomes between hospitalized COVID-19 patients who received their annual influenza vaccination and those who did not. Vaccination did not affect the risk of intensive care unit admission, intubation, complications, or mortality. Further meta-analyses including randomized controlled studies with increased sample sizes are needed to validate these findings.

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE (2021)

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Article Multidisciplinary Sciences

Examining the potential benefits of the influenza vaccine against SARS-CoV-2: A retrospective cohort analysis of 74,754 patients

Susan M. Taghioff et al.

Summary: This study analyzed data from over 73 million patients to investigate the potential benefits of influenza vaccination in reducing adverse outcomes in SARS-CoV-2 positive patients. Results showed that receiving the influenza vaccine was associated with decreased risks of sepsis, stroke, ICU admissions, deep vein thrombosis (DVT), and emergency department visits in SARS-CoV-2 positive patients. Further prospective studies are needed to explore this potential protective effect.

PLOS ONE (2021)

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Article Virology

Prevalence, Persistence, and Factors Associated with SARS-CoV-2 IgG Seropositivity in a Large Cohort of Healthcare Workers in a Tertiary Care University Hospital in Northern Italy

Gitana Scozzari et al.

Summary: This observational study assessed SARS-CoV-2 IgG seroprevalence among workers in Northwestern Italy after the first pandemic wave. It found that self-reporting of COVID-19 suspected symptoms, work contacts, and household contacts were significant factors associated with positivity. The study also revealed an inverse association between active smoking and seroprevalence.

VIRUSES-BASEL (2021)

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Article Multidisciplinary Sciences

Impact of COVID-19 outbreaks and interventions on influenza in China and the United States

Luzhao Feng et al.

Summary: Research suggests that COVID-19 outbreaks and related NPIs may have significantly reduced influenza activity in China and the United States during the 2019-2020 season, indicating a potential impact of NPIs on the spread of infectious diseases.

NATURE COMMUNICATIONS (2021)

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Article Pharmacology & Pharmacy

Exploring Drugs and Vaccines Associated with Altered Risks and Severity of COVID-19: A UK Biobank Cohort Study of All ATC Level-4 Drug Categories Reveals Repositioning Opportunities

Yong Xiang et al.

Summary: This study utilized a medical informatics approach to repositioning drugs for COVID-19 treatment, using data from the UK-Biobank. The analysis revealed many potential drug repositioning candidates, particularly cardiovascular medications, showing protective associations with COVID-19 diagnosis and severity. Differences in protective effects were observed in various subgroups, for example weaker protection by flu/pneumococcal vaccines in obese individuals and stronger protection by statins in cardiovascular patients. Further validation studies are needed.

PHARMACEUTICS (2021)

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Review Immunology

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

Ruitong Wang et al.

Summary: The study found that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection, but not significantly associated with adverse outcomes. Influenza vaccination may have benefits for COVID-19 prevention.

VACCINES (2021)

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Review Infectious Diseases

Co-infection of SARS-CoV-2 and influenza viruses: A systematic review and meta-analysis

Thi Loi Dao et al.

Summary: This meta-analysis revealed that the proportion of influenza virus co-infection in SARS-CoV-2 positive patients was 0.7%, with most cases being due to influenza A virus. Children had a significantly higher co-infection rate with influenza viruses compared to adults, and critically ill patients tended to have a slightly higher co-infection rate than overall patients.

JOURNAL OF CLINICAL VIROLOGY PLUS (2021)

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Article Public, Environmental & Occupational Health

The Incoming Influenza Season - China, the United Kingdom, and the United States, 2021-2022

Shasha Han et al.

Summary: Global seasonal influenza activity has declined during the COVID-19 pandemic, particularly in China. For the upcoming 2021-2022 influenza season, studies suggest that influenza activity may remain low if mask-wearing interventions continue or if mobility levels remain low.

CHINA CDC WEEKLY (2021)

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Article Medicine, General & Internal

Inactivated trivalent influenza vaccination is associated with lower mortality among patients with COVID-19 in Brazil

Guenther Fink et al.

Summary: The study found that COVID-19 patients who received recent inactivated influenza vaccination in Brazil had lower odds of needing intensive care treatment, requiring invasive respiratory support, and death. These protective effects were more significant when the vaccine was administered after symptom onset and among younger patients.

BMJ EVIDENCE-BASED MEDICINE (2021)

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Article Multidisciplinary Sciences

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

Kelly Huang et al.

Summary: The study suggests that receiving the influenza vaccine may reduce the risk of COVID-19 infection and the severity of the illness.

SCIENTIFIC REPORTS (2021)

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Review Immunology

A guide to vaccinology: from basic principles to new developments

Andrew J. Pollard et al.

Summary: Immunization is vital for public health policy and there are challenges ahead for immunologists in developing new vaccines. Although immunology has not contributed significantly to vaccine development so far, a better understanding of protective immunity is urgently needed to tackle difficult-to-target pathogens.

NATURE REVIEWS IMMUNOLOGY (2021)

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Article Respiratory System

Association between influenza vaccination and hospitalisation or all-cause mortality in people with COVID-19: a retrospective cohort study

Christopher R. Wilcox et al.

Summary: This study found that receiving influenza vaccination was associated with lower odds of hospitalization or all-cause mortality in COVID-19 patients, urging for urgent expansion of the UK influenza vaccination program as a key component of the ongoing response plans to the COVID-19 pandemic.

BMJ OPEN RESPIRATORY RESEARCH (2021)

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Letter Cell Biology