Influenza vaccination and respiratory virus interference among Department of Defense personnel during the 2017-2018 influenza season

Non-specific effects of the inactivated influenza vaccine. A test-negative study: The inactivated influenza vaccine and SARS-CoV-2 infections

BACKGROUND

Previous research suggested that the inactivated influenza vaccine (IIV) may protect against SARS-CoV-2 infection or a severe course of COVID-19. These findings were however based on cohort studies, that are prone to confounding by indication. We examined the association between IIV and SARS-Cov-2 infection in a Dutch population using a test-negative design.

METHODS

This test-negative case-control study was conducted in adults (≥60) who tested because of COVID-19 like symptoms at community SARS-CoV-2 testing locations in the Netherlands during the period of November 8th 2021-March 11th 2022. Information on receipt of IIV in October-November 2021 was routinely collected at each visit. Logistic regression was used to calculate unadjusted, partially (sex, age, education level) and fully adjusted (COVID-19 vaccination, IIV 2020) odds ratios (ORs) for receipt of IIV in SARS-CoV-2 positive versus negative subjects. Differential effects on SARS-CoV-2 risk by time since IIV were investigated by including an interaction term for calendar time: November 2021-January 2022 vs February-March 2022.

RESULTS

In total, 1,832 participants were included in the main analysis, of whom 336 (18.3 %) had a positive SARS-CoV-2 test. No significant association between IIV and SARS-CoV-2 infection was found; fully adjusted OR of 1.07 (95 % CI: 0.78-1.49). The interaction term for time periods was not significant (1.04 [95 % CI: 0.51-2.15], p = 0.91). Results were robust in sensitivity analyses.

CONCLUSIONS

While earlier observational studies suggested a protective non-specific effect of IIV and SARS-CoV-2 infections, this smaller, but well controlled test-negative design study does not suggest an effect, either positive or negative. Larger test-negative design studies, or alternative designs such as the self-controlled case series design are needed to confirm these findings and provide more definite answers on the topic.

Influenza vaccination and COVID-19 Infection Risk and Disease Severity: A systematic review and multi-level meta-analysis of prospective studies

BACKGROUND

In light of the SARS-CoV-2 pandemic, the influence of influenza vaccination on the risk and severity of COVID-19 has been a subject of debate. This systematic review and meta-analysis of prospective studies aim to elucidate the association between influenza immunization and the risk of SARS-CoV-2 infection and subsequent COVID-19 disease severity.

METHODS

A comprehensive search of PubMed and Embase databases was performed to identify prospective studies published before March 2024. We focused on evaluating the effect of influenza vaccination on SARS-CoV-2 infection risk and severe COVID-19 outcomes, such as hospitalization and mortality. The analysis employed a multi-level random effects meta-analysis approach. The risk of bias assessment was conducted using the Newcastle-Ottawa Scale (NOS).

RESULTS

From an initial pool of 5863 records, 14 studies were selected for inclusion. The aggregated data yielded a Summary Relative Risk (SRR) that showed no significant protective correlation between influenza vaccination and SARS-CoV-2 infection risk (SRR 0.95, 95%CI 0.81-1.11), COVID-19-associated hospitalization (SRR 0.90, 95%CI 0.68-1.19), or COVID-19-related mortality (SRR 0.83, 95%CI 0.56-1.23).

CONCLUSIONS

This systematic review and meta-analysis, based exclusively on prospective studies, demonstrates the lack of a proven protective effect of influenza vaccination against COVID-19 and related outcomes. Our results do not support a significant protective effect of influenza vaccination against the risk or severe outcomes of COVID-19.

Decreased risk of non-influenza respiratory infection after influenza B virus infection in children

Previous studies suggest that influenza virus infection may provide temporary non-specific immunity and hence lower the risk of non-influenza respiratory virus infection. In a randomized controlled trial of influenza vaccination, 1 330 children were followed-up in 2009-2011. Respiratory swabs were collected when they reported acute respiratory illness and tested against influenza and other respiratory viruses. We used Poisson regression to compare the incidence of non-influenza respiratory virus infection before and after influenza virus infection. Based on 52 children with influenza B virus infection, the incidence rate ratio (IRR) of non-influenza respiratory virus infection after influenza virus infection was 0.47 (95% confidence interval: 0.27-0.82) compared with before infection. Simulation suggested that this IRR was 0.87 if the temporary protection did not exist. We identified a decreased risk of non-influenza respiratory virus infection after influenza B virus infection in children. Further investigation is needed to determine if this decreased risk could be attributed to temporary non-specific immunity acquired from influenza virus infection.

Implications of vaccine non-specific effects on licensure of new vaccines

Immune memory was for a long time thought to be an exclusive feature of the adaptive immune system. Emerging evidence has shown that the innate immune system may exhibit memory which has been termed as trained immunity or innate immune memory. Trained immunity following vaccination may produce non-specific effects leading to reduction in morbidity and mortality from heterologous pathogens. This review looked at trained immunity as a mechanism for vaccine induced non-specific effects, mechanisms underlying trained immunity and known vaccine non-specific effects. A discussion is also made on the implications these vaccine non-specific effects may have on overall risk-benefit ratio evaluation by National Medicines Regulatory Authorities (NMRAs) during licensure of new vaccines. Epigenetic remodeling and "rewiring" of cellular metabolism in the innate immune cells especially monocytes, macrophages, and Natural Killer (NK) cells have been suggested to be the mechanisms underlying trained immunity. Trained immunity in other innate cells has largely remained elusive up to date. Non-specific effects have been extensively documented with Bacille Calmette-Guerin (BCG), measles vaccine and oral polio vaccine but it remains unclear if other vaccines may exhibit similar effects. All known vaccine non-specific effects have come from observations in epidemiological studies conducted post-vaccine licensure and roll out in target populations. It remains to be seen if early identification of non-specific effects especially those with protective benefits during the clinical development of new vaccines may contribute to the overall risk-benefit ratio evaluation during licensure by NMRAs.

Effect of monovalent COVID-19 vaccines on viral interference between SARS-CoV-2 and several DNA viruses in patients with long-COVID syndrome

Epstein-Barr virus (EBV) reactivation may be involved in long-COVID symptoms, but reactivation of other viruses as a factor has received less attention. Here we evaluated the reactivation of parvovirus-B19 and several members of the Herpesviridae family (DNA viruses) in patients with long-COVID syndrome. We hypothesized that monovalent COVID-19 vaccines inhibit viral interference between SARS-CoV-2 and several DNA viruses in patients with long-COVID syndrome, thereby reducing clinical symptoms. Clinical and laboratory data for 252 consecutive patients with PCR-verified past SARS-CoV-2 infection and long-COVID syndrome (155 vaccinated and 97 non-vaccinated) were recorded during April 2021-May 2022 (median 243 days post-COVID-19 infection). DNA virus-related IgG and IgM titers were compared between vaccinated and non-vaccinated long-COVID patients and with age- and sex-matched non-infected, unvaccinated (pan-negative for spike-antibody) controls. Vaccination with monovalent COVID-19 vaccines was associated with significantly less frequent fatigue and multiorgan symptoms (p < 0.001), significantly less cumulative DNA virus-related IgM positivity, significantly lower levels of plasma IgG subfractions 2 and 4, and significantly lower quantitative cytomegalovirus IgG and IgM and EBV IgM titers. These results indicate that anti-SARS-CoV-2 vaccination may interrupt viral cross-talk in patients with long-COVID syndrome (ClinicalTrials.gov Identifier: NCT05398952).

A cross-sectional study from Qatar on the effect of influenza vaccination on the severity of COVID-19

To assess and compare the severity of corona virus disease 2019 (COVID-19) infection in patients with and without a history of influenza vaccination. In this cross-sectional study descriptive statistics were used to analyze COVID-19-related parameters, including demographics, comorbidities, and severity. Normally distributed data with mean, standard deviation, and 95% confidence interval (CI) were reported, while non-normally distributed data was presented with median and inter-quartile range. Categorical data was summarized using frequencies and percentages. Associations were assessed using Pearson Chi-square, Fisher Exact, t test, or Mann-Whitney U test. Univariate and multivariate logistic regression methods were used to evaluate the relationship between disease severity, clinical outcomes, influenza vaccination status, and other predictors. Significance was considered for p values < 0.05. Statistical analyses were done using SPSS V.27.0 (IBM Corp) and Epi Info (CDC) software. Between March 2020 and December 2020 before the availability of COVID-19 vaccination, 148,215 severe acute respiratory syndrome corona virus 2 positive patients were studied, with 3519 vaccinated against influenza, and 144,696 unvaccinated. After random sampling at 1:2 ratio, the final analysis included 3234 vaccinated and 5640 unvaccinated patients. The majority (95.4%) had mild or asymptomatic COVID-19, while 4.6% had severe or critical cases as defined by World Health Organization severity grading. Multivariate logistic regression analysis revealed that the vaccinated group had significantly less severe (adjusted odds ratio [OR] 0.683; 95% CI 0.513-0.911, P = .009) and critical (adjusted OR 0.345; 95% CI 0.145-0.822, P = .016) COVID-19 and were less likely to require oxygen therapy (adjusted OR 0.696; 95% CI 0.531-0.912, P = .009) after adjusting for confounders like age, gender and comorbidities. No significant differences in Intensive care unit admissions (adjusted OR 0.686; 95% CI 0.425-1.11, P = .122), mechanical ventilation (adjusted OR 0.631; 95% CI 0.308-1.295, P = .209) and mortality (adjusted OR 1.105; 95% CI 0.348-3.503, P = .866) were noted between the 2 groups. Influenza vaccination may significantly reduce the severity of COVID-19 but has no significant effect on intensive care unit admissions, mechanical ventilation and all- cause mortality.

The impact of influenza vaccination on surgical outcomes in COVID-19 positive patients: An analysis of 43,580 patients

BACKGROUND

Multiple recent studies suggest a possible protective effect of the influenza vaccine against severe acute respiratory coronavirus 2 (SARS-CoV-2). This effect has yet to be evaluated in surgical patients. This study utilizes a continuously updated federated electronic medical record (EMR) network (TriNetX, Cambridge, MA) to analyze the influence of the influenza vaccine against post-operative complications in SARS-CoV-2-positive patients.

METHODS

The de-identified records of 73,341,020 patients globally were retrospectively screened. Two balanced cohorts totaling 43,580 surgical patients were assessed from January 2020-January 2021. Cohort One received the influenza vaccine six months-two weeks prior to SARS-CoV-2-positive diagnosis, while Cohort Two did not. Post-operative complications within 30, 60, 90, and 120 days of undergoing surgery were analyzed using common procedural terminology(CPT) codes. Outcomes were propensity score matched for characteristics including age, race, gender, diabetes, obesity, and smoking.

RESULTS

SARS-CoV-2-positive patients receiving the influenza vaccine experienced significantly decreased risks of sepsis, deep vein thrombosis, dehiscence, acute myocardial infarction, surgical site infections, and death across multiple time points(p<0.05, Bonferroni Correction p = 0.0011). Number needed to vaccinate (NNV) was calculated for all significant and nominally significant findings.

CONCLUSION

Our analysis examines the potential protective effect of influenza vaccination in SARS-CoV-2-positive surgical patients. Limitations include this study's retrospective nature and reliance on accuracy of medical coding. Future prospective studies are warranted to confirm our findings.

Cancer patients and COVID-19 vaccination, from safety to protocol adherence: A real-life setting report

Background

The SARS-CoV-2 pandemic has slowed down cancer prevention and treatment strategies; consequently, cancer patients are prioritized to get the COVID-19 vaccines. Being constantly threatened by a new outbreak, the dive within the immunogenicity response is of great value; nonetheless, evaluating the side effects of these vaccines on fragile patients will assure their adherence to the vaccination protocol.

Objectives

This study sets out to investigate the adverse events reported about the vaccine according to its doses and types, and to compare the prevalence and severity of toxicities across two subgroups of cancer patients, those who received the injection during active therapy cycles, and those who have not started the therapy yet at vaccination time, moreover, this paper examines the will and commitment of this population to the vaccination schemes.

Methods

This is an observational, retrospective, cohort study, in which we conducted a semi-constructed interview with 415 random solid cancer patients treated at the National Institute of Oncology in Morocco. The assessment of adverse events was carried out with a standardized scale.

Results

Eleven months after the launch of the campaign, 75.2% of patients received at least one dose of the vaccine. Altogether, the analysis demonstrates a significant difference between the adverse effects reported post the second dose compared to the first one (p=0.004; odds ratio=2 [95% CI: 1.23 - 3.31]). Besides, the results indicate an increase in the rank of the severity of systemic events (p<0.001, r=0.28) after the second dose, but not for the local events (p=0.92, r=0.005). In the adjusted subgroup analysis, no effect was detected linking active therapy with the occurrence of toxicity (p=0.51, v=0.04) as well as with the level of severity reported after both; the first and second dose. Due to the fear of interactions with the therapy, we noticed a significant trend to delay the booster dose among the participants who completed the initial vaccine protocol.

Conclusion

A considerable body of evidence exists to persuade cancer patients to take the Coronavirus vaccines, and to also follow their vaccination schemes under the supervision of their treating physicians.

Roles for Pathogen Interference in Influenza Vaccination, with Implications to Vaccine Effectiveness (VE) and Attribution of Influenza Deaths

Pathogen interference is the ability of one pathogen to alter the course and clinical outcomes of infection by another. With up to 3000 species of human pathogens the potential combinations are vast. These combinations operate within further immune complexity induced by infection with multiple persistent pathogens, and by the role which the human microbiome plays in maintaining health, immune function, and resistance to infection. All the above are further complicated by malnutrition in children and the elderly. Influenza vaccination offers a measure of protection for elderly individuals subsequently infected with influenza. However, all vaccines induce both specific and non-specific effects. The specific effects involve stimulation of humoral and cellular immunity, while the nonspecific effects are far more nuanced including changes in gene expression patterns and production of small RNAs which contribute to pathogen interference. Little is known about the outcomes of vaccinated elderly not subsequently infected with influenza but infected with multiple other non-influenza winter pathogens. In this review we propose that in certain years the specific antigen mix in the seasonal influenza vaccine inadvertently increases the risk of infection from other non-influenza pathogens. The possibility that vaccination could upset the pathogen balance, and that the timing of vaccination relative to the pathogen balance was critical to success, was proposed in 2010 but was seemingly ignored. Persons vaccinated early in the winter are more likely to experience higher pathogen interference. Implications to the estimation of vaccine effectiveness and influenza deaths are discussed.

Impact of influenza vaccination on GP-diagnosed COVID-19 and all-cause mortality: a Dutch cohort study

OBJECTIVES

As clinical presentation and complications of both viruses overlap, it was hypothesised that influenza vaccination was associated with lower general practitioner (GP)-diagnosed COVID-19 rates and lower all-cause mortality rates.

STUDY DESIGN

From a primary care population-based cohort in the Netherlands, GP-diagnosed COVID-19 (between 10 March and 22 November 2020) and all-cause mortality events (between 30 December 2019 and 22 November 2020) were recorded. 223 580 persons were included, representing the influenza vaccination 2019 target group (all aged ≥60 years, and those <60 years with a medical indication). Proportional hazards regression analyses evaluated associations between influenza vaccination in 2019 and two outcomes: GP-diagnosed COVID-19 and all-cause mortality. Covariables were sex, age, comorbidities and number of acute respiratory infection primary care consultations in 2019.

RESULTS

A slightly positive association (HR 1.15; 95% CI 1.08 to 1.22) was found between influenza vaccination in 2019 and GP-diagnosed COVID-19, after adjusting for covariables. A slightly protective effect for all-cause mortality rates (HR 0.90; 95% CI 0.83 to 0.97) was found for influenza vaccination, after adjusting for covariables. A subgroup analysis among GP-diagnosed COVID-19 cases showed no significant association between influenza vaccination in 2019 and all-cause mortality.

CONCLUSIONS

Our hypothesis of a possibly negative association between influenza vaccination in 2019 and GP-diagnosed COVID-19 was not confirmed as we found a slightly positive association. A slightly protective effect on all-cause mortality was found after influenza vaccination, possibly by a wider, overall protective effect on health. Future research designs should include test-confirmed COVID-19 cases and controls, adjustments for behavioural, socioeconomic and ethnic factors and validated cause-specific mortality cases.

Effects of Confounding Bias in Coronavirus Disease 2019 (COVID-19) and Influenza Vaccine Effectiveness Test-Negative Designs Due to Correlated Influenza and COVID-19 Vaccination Behaviors

BACKGROUND

The test-negative design is commonly used to estimate influenza and coronavirus disease 2019 (COVID-19) vaccine effectiveness (VE). In these studies, correlated COVID-19 and influenza vaccine behaviors may introduce a confounding bias where controls are included with the other vaccine-preventable acute respiratory illness (ARI). We quantified the impact of this bias on VE estimates in studies where this bias is not addressed.

METHODS

We simulated study populations under varying vaccination probabilities, COVID-19 VE, influenza VE, and proportions of controls included with the other vaccine-preventable ARI. Mean bias was calculated as the difference between estimated and true VE. Absolute mean bias in VE estimates was classified as low (<10%), moderate (10% to <20%), and high (≥20%).

RESULTS

Where vaccination probabilities are positively correlated, COVID-19 and influenza VE test-negative studies with influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ARI controls, respectively, underestimate VE. For COVID-19 VE studies, mean bias was low for all scenarios where influenza represented ≤25% of controls. For influenza VE studies, mean bias was low for all scenarios where SARS-CoV-2 represented ≤10% of controls. Although bias was driven by the conditional probability of vaccination, low VE of the vaccine of interest and high VE of the confounding vaccine increase its magnitude.

CONCLUSIONS

Where a low percentage of controls is included with the other vaccine-preventable ARI, bias in COVID-19 and influenza VE estimates is low. However, influenza VE estimates are likely more susceptible to bias. Researchers should consider potential bias and its implications in their respective study settings to make informed methodological decisions in test-negative VE studies.

Identifying factors associated with COVID-19 related deaths during the first wave of the pandemic in Europe

Aim

To clarify the high variability in COVID-19-related deaths during the first wave of the pandemic, we conducted a modeling study using publicly available data.

Materials and methods

We used 13 population- and country-specific variables to predict the number of population-standardized COVID-19-related deaths in 43 European countries using generalized linear models: the test-standardized number of SARS-CoV-2-cases, population density, life expectancy, severity of governmental responses, influenza-vaccination coverage in the elderly, vitamin D status, smoking and diabetes prevalence, cardiovascular disease death rate, number of hospital beds, gross domestic product, human development index and percentage of people older than 65 years.

Results

We found that test-standardized number of SARS-CoV-2-cases and flu vaccination coverage in the elderly were the most important predictors, together with vitamin D status, gross domestic product, population density and government response severity explaining roughly two-thirds of the variation in COVID-19 related deaths. The latter variable was positively, but only weakly associated with the outcome, i.e., deaths were higher in countries with more severe government response. Higher flu vaccination coverage and low vitamin D status were associated with more COVID-19 related deaths. Most other predictors appeared to be negligible.

Conclusion

Adequate vitamin D levels are important, while flu-vaccination in the elderly and stronger government response were putative aggravating factors of COVID-19 related deaths. These results may inform protection strategies against future infectious disease outbreaks.

How influenza vaccination and virus interference may impact combined influenza-coronavirus disease burden

Demand for influenza vaccine rose as countries prepared for the second COVID-19 wave over the winter months of 2020-2021. High coverage of the influenza vaccine can significantly reduce morbidity and mortality of the burden of influenza. Natural influenza infection creates short-term non-specific immunity against respiratory viruses (virus interference). We model two viral diseases, both of the SEIR type, to investigate whether the influenza vaccine increases the combined disease burden of influenza and COVID-19 in a dual outbreak. We show that the combined disease burden’s behavior depends on virus interference factors and the proportion of the population vaccinated against influenza. Our results indicate that influenza vaccination only lowers the overall disease burden when net virus interference is relatively low.

Clinical characteristics and risk factors for COVID-19 infection and disease severity: A nationwide observational study in Estonia

BACKGROUND

COVID-19 pandemic has led to overloading of health systems all over the world. For reliable risk stratification, knowledge on factors predisposing to SARS-CoV-2 infection and to severe COVID-19 disease course is needed for decision-making at the individual, provider, and government levels. Data to identify these factors should be easily obtainable.

METHODS AND FINDINGS

Retrospective cohort study of nationwide e-health databases in Estonia. We used longitudinal health records from 66,295 people tested positive for SARS-CoV-2 RNA from 26 February 2020 to 28 February 2021 and 254,958 randomly selected controls from the reference population with no known history of SARS-CoV-2 infection or clinical COVID-19 diagnosis (case to control ratio 1:4) to predict risk factors of infection and severe course of COVID-19. We analysed sociodemographic and health characteristics of study participants. The SARS-CoV-2 infection risk was slightly higher among women, and was higher among those with comorbid conditions or obesity. Dementia (RRR 3.77, 95%CI 3.30⎼4.31), renal disease (RRR 1.88, 95%CI 1.56⎼2.26), and cerebrovascular disease (RRR 1.81, 95%CI 1.64⎼2.00) increased the risk of infection. Of all SARS-CoV-2 infected people, 92% had a non-severe disease course, 4.8% severe disease (requiring hospitalisation), 1.7% critical disease (needing intensive care), and 1.5% died. Male sex, increasing age and comorbid burden contributed significantly to more severe COVID-19, and the strength of association for male sex increased with the increasing severity of COVID-19 outcome. The strongest contributors to critical illness (expressed as RRR with 95% CI) were renal disease (7.71, 4.71⎼12.62), the history of previous myocardial infarction (3.54, 2.49⎼5.02) and obesity (3.56, 2.82⎼4.49). The strongest contributors to a lethal outcome were renal disease (6.48, 3.74⎼11.23), cancer (3.81, 3.06⎼4.75), liver disease (3.51, 1.36⎼9.02) and cerebrovascular disease (3.00, 2.31⎼3.89).

CONCLUSIONS

We found divergent effect of age and gender on infection risk and severity of COVID-19. Age and gender did not contribute substantially to infection risk, but did so for the risk of severe disease Co-morbid health conditions, especially those affecting renin-angiotensin system, had an impact on both the risk of infection and severe disease course. Age and male sex had the most significant impact on the risk of severe COVID-19. Taking into account the role of ACE2 receptors in the pathogenesis of SARS-CoV-2 infection, as well as its modulating action on the renin-angiotensin system in cardiovascular and renal diseases, further research is needed to investigate the influence of hormonal status on ACE2 expression in different tissues, which may be the basis for the development of COVID-19 therapies.

Co-infection of SARS-CoV-2 with other viral respiratory pathogens in Yogyakarta, Indonesia: A cross-sectional study

Background

Growing evidence shows that viral co-infection is found repeatedly in patients with Coronavirus Disease–2019 (COVID-19). This is the first report of SARS-CoV-2 co-infection with viral respiratory pathogens in Indonesia.

Methods

Over a one month period of April to May 2020, SARS-CoV-2 positive nasopharyngeal swabs in our COVID-19 referral laboratory in Yogyakarta, Indonesia, were tested for viral respiratory pathogens by real-time, reverse transcription polymerase chain reaction (RT-PCR). Proportion of co-infection reported in percentage.

Results

Fifty-nine samples were positive for other viral respiratory pathogens among a total of 125 samples. Influenza A virus was detected in 32 samples, Influenza B in 16 samples, Human metapneumovirus in 1 sample, and adenovirus in 10 samples. We did not detect any co-infection with respiratory syncytial virus. Nine (7.2%) patients had co-infection with more than two viruses.

Conclusion

Viral co-infection with SARS-CoV-2 is common. These results will provide a helpful reference for diagnosis and clinical treatment of patients with COVID-19.

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Viral co-infection with SARS-CoV-2 is common.

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Co-infection by two viral respiratory pathogens is prevalent.

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Pandemic transmission control may also impact in other viral respiratory infections.

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Early identification of co-infection is necessary, given differences in treatment.

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Simple laboratory diagnosis algorithm may be applied to screen viral co-infection.

Flu vaccination in multiple sclerosis patients: a monocentric prospective vaccine-vigilance study

BACKGROUND

In 2020, the Italian Medicines Agency recommended to bring forward the flu vaccination campaign, whose importance was also emphasized for patients with Multiple Sclerosis (MS). We aimed to assess the safety profile of flu vaccines in terms of occurrence of short-term and long-term Adverse Events Following Immunization (AEFIs).

METHODS

This is an observational study that enrolled MS patients who were eligible for any of the flu vaccines recommended by the Italian medicines Agency.

RESULTS

194 patients were enrolled. Out of 133 patients who accepted to be vaccinated, 45 experienced not serious short-term AEFIs (pain at the injection site, headache, flu-like symptoms, fatigue). Long-term AEs were detected in 12 vaccinated patients (flu-like symptoms, COVID-19 and MS relapse). No statistically significant differences in terms of infections or MS relapse were found between vaccinated and unvaccinated groups. Using Kaplan-Meier analysis we observed no differences in the cumulative survival rate in both groups.

CONCLUSION

Flu vaccines were well tolerated in MS patients, who mainly experienced not serious short term AEFIs. Considering that COVID-19 vaccines campaign is still ongoing among MS patients, our results might bring new knowledge concerning the safety profile of vaccines in this frail population.

Does influenza vaccination help reduce incidence of COVID-19 infection among hospital employees?

To facilitate the understanding of the interaction between severe acute respiratory syndrome coronavirus 2 causing the corona virus disease 2019 (COVID-19) and other pathogens causing respiratory system affection we investigated the effect of influenza vaccination on the incidence and severity of COVID-19 among members of staff working in the Bahrain Defense Force Hospital.All staff members working in the hospital between February 2020 and March 2021 were divided into 2 main groups based on whether or not they received influenza vaccination. None of the participants had received any of the COVID-19 vaccines throughout this time period. The records of each were scrutinized to see the effect of influenza vaccination on incidence and severity of COVID-19. Severity measures were: need for hospital and intensive care unit admission and total length of hospital stay.Incidence of affection with COVID-19 was much lower in the vaccinated group (3.7% vs 8.1%, P < .001). Influenza vaccination also reduced total length of hospital stay (6.2 days vs 12.7 days, P < .05) and need for intensive care unit admission among the patients.Influenza vaccine reduces both the incidence of affection as well as the overall burden of COVID-19. This is of particular importance for people working in the healthcare field during the serious COVID-19 pandemic.

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

AIM OF THE STUDY

The impact of annual flu vaccination on the patients' clinical course with COVID-19 and the outcome were tested.

METHODS

A total of 149 patients with COVID-19-positive admitted from March 20 to May 10, 2020, were retrospectively enrolled.

RESULTS

Ninety-eight (65.8%) patients received at least a single annual flu shot in the last year, and fifty-one (34.2%) were never vaccinated. On presentation, vaccinated patients were more likely to present with gastrointestinal symptoms (P < .05). There were no significant differences between study groups in laboratory findings or clinical outcomes. In multivariate analysis, receiving the annual shot did not influence risk of intensive care unit admission (OR = 1.17, 95%CI = 0.50-2.72, P = .72), intubation (OR = 1.40, 95%CI = 0.60-3.23, P = .43), complications (OR = 1.08, 95%CI = 0.52-2.26, P = .83) or mortality (OR = 1.29, 95%CI = 0.31-5.29, P = .73).

CONCLUSION

Although the benefits of the influenza vaccine for preventing disease and reducing morbidity in influenza patients are well established, no differences in outcomes for hospitalised patients with COVID-19 who received their annual influenza vaccination versus the non-vaccinated cohort were evident. There is a need for future meta-analyses, including randomised controlled studies in which the number of cases is increased to validate these findings.

Effect of inactivated influenza vaccination on human coronavirus infection: Secondary analysis of a randomized trial in Hutterite colonies

Background

Although influenza vaccines provide protection against influenza viruses, concern has been raised that they may increase susceptibility to non-influenza respiratory viruses. As pandemic lockdowns end, temporal overlap of circulation of seasonal influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is expected. Understanding the impact of influenza vaccination on risk of coronavirus infection is therefore of considerable public health importance.

Methods

We performed a secondary analysis of a randomized trial where children and adolescents in Canadian Hutterite colonies were randomly assigned by colony to receive the 2008–2009 seasonal inactivated trivalent influenza vaccine (TIV) or a control hepatitis A (HepA) vaccine. All 3273 colony members (vaccinated children and nonvaccine recipients) were followed for the primary outcome of RT-PCR confirmed seasonal coronavirus infection. Serum collected pre- and post-vaccination was analyzed for titers of IgG antibodies towards human coronaviruses (HCoV).

Results

The incidence of coronavirus infection was 0·18/1000 person-days in the colonies that received TIV vs 0.36/1000 person-days in the control group, hazard ratio (HR) 0.49 [0.21–1.17]. The risk reduction among non-vaccine recipients in the TIV group compared to the control group was HR 0.55 [0.24–1.23]. There was an increase in the geometric mean fold change of HCoV-OC43 antibody titers following TIV compared to HepA vaccine (mean difference 1.2 [0.38–2.06], p = 0.007), and an increase in geometric mean HCoV-NL63 antibody titers post-TIV (262.9 vs 342.9, p = 0.03).

Conclusion

The influenza vaccine does not increase the risk of a coronavirus infection. Instead, the influenza vaccine may reduce the rate of coronavirus infections by inducing cross-reactive anti-coronavirus IgG antibodies.

Esquemas completos aplicados contra COVID-19 priorizados por entidad territorial en Colombia

Introducción: el 6 de marzo 2020 Colombia registró el primer caso de infección por SARS-CoV-2. Con la cuarentena se enfrentaba también el temor popular acerca del riesgo de seguir con la vacunación usual en tiempos de COVID-19 y de cómo esta podría influir en forma negativa en el término de la infección por SARS-CoV-2. Objetivo: mostrar el avance de la población priorizada para la vacunación contra SARS-CoV-2 en las entidades territoriales de Colombia, además de los esquemas completos y el porcentaje priorizado, en el periodo comprendido entre el 17 de febrero a 26 de julio 2021. Metodología: esta investigación es un estudio transversal, como fuente de información se obtuvo del plan nacional de vacunación contra el COVID-19 de la página web del Ministerio de Salud y Protección Social. Resultados: las entidades territoriales con mayor número de población priorizada para la vacunación fueron: Antioquia (2’583.113), Bogotá (2’077.324), Valle del Cauca (1’437.805), Cundinamarca (1’095.364) y Santander (797.740); entre las entidades territoriales con mayor número de esquemas completos de vacunación estuvieron: Bogotá (1’168.212), Antioquia (620.133), Valle del Cauca (576.283), Santander (335.015) y Norte de Santander (232.110). Se concluyó que los territorios con mayor número de porcentaje priorizado de vacunación fueron: Amazonas (128%), Vaupés (119,92%), Guainía (93,6%), Bogotá (56,24%) y Quindío (51, 73%).Conclusión: es fundamental seguir los resultados de los esquemas de vacunación a nivel territorial para entender su eficacia, la posible reducción de la respuesta inmune con el tiempo y las posibles consecuencias adversas.

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

The association of influenza vaccine and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was assessed by test-negative design using data collected for a study of outpatient COVID-19-like illness with onset dates from June to September 2020. Multivariable logistic regression models examined the association between receipt of 2019-2020 influenza vaccine and PCR-confirmed SARS-CoV-2 with adjustment for potential confounders. Receipt of influenza vaccine during the 2019-2020 influenza season was not associated with increased odds of SARS-CoV-2 infection in adults (aOR 0.83, 95% CI 0.63 to 1.10) or children (aOR 0.92, 95% CI 0.47 to 1.80).

Influenza vaccine during the 2019-2020 season and COVID-19 risk: A case-control study in Québec

Background

We carried out a case-control study that examined whether receipt of the inactivated influenza vaccine during the 2019-2020 season impacted on the risk of coronavirus disease 2019 (COVID-19), as there was a concern that the vaccine could be detrimental through viral interference.

Methods

A total of 920 cases with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (diagnosed between March and October 2020) and 2,123 uninfected controls were recruited from those who were born in Québec between 1956 and 1976 and who had received diagnostic services at two hospitals (Montréal and Sherbrooke, Québec). After obtaining consent, a questionnaire was administered by phone. Data were analyzed by logistic regression.

Results

Among healthcare workers, inactivated influenza vaccine received during the previous influenza season was not associated with increased COVID-19 risk (AOR: 0.99, 95% CI: 0.69-1.41). Among participants who were not healthcare workers, influenza vaccination was associated with lower odds of COVID-19 (AOR: 0.73, 95% CI 0.56-0.96).

Conclusion

We found no evidence that seasonal influenza vaccine increased the risk of developing COVID-19.

HIV self-testing in Ottawa, Canada used by persons at risk for HIV: The GetaKit study

Background

The Public Health Agency of Canada estimates that about 87% of persons living with human immunodeficiency virus (HIV) in Canada have been diagnosed, which is well below the Joint United Nations Programme on HIV/AIDS target to have 95% of HIV-positive persons diagnosed. Research has shown that HIV self-testing may help increase such diagnoses, especially among the populations who are most affected by HIV. The objective of the study was to determine the uptake and diagnosis outcomes associated with free HIV self-testing.

Methods

We developed the first online mailout free HIV self-testing program in Canada and implemented it in Ottawa. This project ran through the website, www.GetaKit.ca. We intended to recruit 150-400 participants over a 6-12-month period, estimating that this number would yield between 0-1 positive test results (expected positivity rate of 0.08%).

Results

Between July 20, 2020 and April 1, 2021, 1,268 people accessed the GetaKit website and verified their eligibility. In total, 600 persons were eligible and 405 ordered an HIV kit. Of those who ordered a kit, 399 completed a baseline survey. Overall, 71% of these participants were members of HIV priority groups. For test results, 228 persons reported test results, with one being positive, for a positivity rate of 0.24% overall and 0.44% of reported results. These rates exceed that normally observed in Ottawa.

Conclusion

Self-testing of HIV can be effectively delivered through a website. Such an intervention will also be used by persons with undiagnosed infections and appears to do so at a rate higher than that observed by other means of testing. Self-testing of HIV may therefore help Canada achieve the United Nations 95-95-95 targets.

Increased lethality in influenza and SARS-CoV-2 coinfection is prevented by influenza immunity but not SARS-CoV-2 immunity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. The continued spread of SARS-CoV-2 increases the probability of influenza/SARS-CoV-2 coinfection, which may result in severe disease. In this study, we examine the disease outcome of influenza A virus (IAV) and SARS-CoV-2 coinfection in K18-hACE2 mice. Our data indicate enhance susceptibility of IAV-infected mice to developing severe disease upon coinfection with SARS-CoV-2 two days later. In contrast to nonfatal influenza and lower mortality rates due to SARS-CoV-2 alone, this coinfection results in severe morbidity and nearly complete mortality. Coinfection is associated with elevated influenza viral loads in respiratory organs. Remarkably, prior immunity to influenza, but not to SARS-CoV-2, prevents severe disease and mortality. This protection is antibody-dependent. These data experimentally support the necessity of seasonal influenza vaccination for reducing the risk of severe influenza/COVID-19 comorbidity during the COVID-19 pandemic.

Influence of Mass Media on Italian Web Users During the COVID-19 Pandemic: Infodemiological Analysis

BACKGROUND

Concurrently with the COVID-19 pandemic, the world has been facing a growing infodemic, which has caused severe damage to economic and health systems and has often compromised the effectiveness of infection containment regulations. Although this infodemic has spread mainly through social media, there are numerous occasions on which mass media outlets have shared dangerous information, giving resonance to statements without a scientific basis. For these reasons, infoveillance and infodemiology methods are increasingly exploited to monitor information traffic on the web and make epidemiological predictions.

OBJECTIVE

The purpose of this paper is to estimate the impact of Italian mass media on users' web searches to understand the role of press and television channels in both the infodemic and the interest of Italian netizens in COVID-19.

METHODS

We collected the headlines published from January 2020 to March 2021 containing specific COVID-19-related keywords published on PubMed, Google, the Italian Ministry of Health website, and the most-read newspapers in Italy. We evaluated the percentages of infodemic terms on these platforms. Through Google Trends, we searched for cross-correlations between newspaper headlines and COVID-19-related web searches. Finally, we analyzed the web interest in infodemic content posted on YouTube.

RESULTS

During the first wave of COVID-19, the Italian press preferred to draw on infodemic terms (rate of adoption: 1.6%-6.3%) and moderately infodemic terms (rate of adoption: 88%-94%), while scientific sources favored the correct names (rate of adoption: 65%-88%). The correlational analysis showed that the press heavily influenced users in adopting terms to identify the novel coronavirus (cross-correlations of ≥0.74 to ≤0.89, P value <.001; maximum lag=1 day). The use of scientific denominations by the press reached acceptable values only during the third wave (approximately 80%, except for the television services Rai and Mediaset). Web queries about COVID-19 symptoms also appeared to be influenced by the press (best average correlation=0.92, P<.007). Furthermore, web users showed pronounced interest in YouTube videos of an infodemic nature. Finally, the press gave resonance to serious "fake news" on COVID-19, which caused pronounced spikes of interest from web users.

CONCLUSIONS

Our results suggest that the Italian mass media have played a decisive role in spreading the COVID-19 infodemic and addressing netizens' web interest, thus favoring the adoption of terms that are unsuitable for identifying COVID-19. Therefore, the directors of news channels and newspapers should be more cautious, and government dissemination agencies should exert more control over such news stories.

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

It has been proposed that vaccines may exert an unspecific protective effect against infectious agents, different than expected. Coronavirus disease 2019 (COVID-19) is a pandemic infection with high mortality in older patients due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The high number of vaccinations may be one of the reasons why children show a lower susceptibility to SARS-CoV-2 infection and milder severity when compared to adults. We have designed a study aimed at investigating whether the influenza vaccine may reduce the susceptibility and severity of SARS-CoV-2 infection. We retrospectively enrolled 635 patients who accessed our Emergency Department from March 1st to June 30th, 2020, and were diagnosed with COVID-19 infection confirmed by an RT-PCR on an oropharyngeal swab. Clinical data, outcomes, and influenza vaccination status were collected from the electronic medical records of our Hospital. We also used data from the Italian Health Ministry to compare the prevalence of flu vaccination among the general population of the Lazio Region and our enrolled patients. We then compared clinical outcomes between vaccinated and non-vaccinated patients, by univariate and multivariate analysis. COVID-19-positive patients older than 65 years reported a lower prevalence of flu vaccination when compared to the general population residing in the Lazio (p = 0.004). After correction for gender, age, and comorbidities, we found a lower risk of death at 60 days in patients with flu vaccination than in not vaccinated patients (p = 0.001). Our study shows that flu vaccination could reduce the mortality of COVID-19. Prospective studies are needed to confirm this result.

Influence of Mass Media on Italian Web Users During the COVID-19 Pandemic: Infodemiological Analysis

BACKGROUND

Concurrently with the COVID-19 pandemic, the world has been facing a growing infodemic, which has caused severe damage to economic and health systems and has often compromised the effectiveness of infection containment regulations. Although this infodemic has spread mainly through social media, there are numerous occasions on which mass media outlets have shared dangerous information, giving resonance to statements without a scientific basis. For these reasons, infoveillance and infodemiology methods are increasingly exploited to monitor information traffic on the web and make epidemiological predictions.

OBJECTIVE

The purpose of this paper is to estimate the impact of Italian mass media on users' web searches to understand the role of press and television channels in both the infodemic and the interest of Italian netizens in COVID-19.

METHODS

We collected the headlines published from January 2020 to March 2021 containing specific COVID-19-related keywords published on PubMed, Google, the Italian Ministry of Health website, and the most-read newspapers in Italy. We evaluated the percentages of infodemic terms on these platforms. Through Google Trends, we searched for cross-correlations between newspaper headlines and COVID-19-related web searches. Finally, we analyzed the web interest in infodemic content posted on YouTube.

RESULTS

During the first wave of COVID-19, the Italian press preferred to draw on infodemic terms (rate of adoption: 1.6%-6.3%) and moderately infodemic terms (rate of adoption: 88%-94%), while scientific sources favored the correct names (rate of adoption: 65%-88%). The correlational analysis showed that the press heavily influenced users in adopting terms to identify the novel coronavirus (cross-correlations of ≥0.74 to ≤0.89, P value <.001; maximum lag=1 day). The use of scientific denominations by the press reached acceptable values only during the third wave (approximately 80%, except for the television services Rai and Mediaset). Web queries about COVID-19 symptoms also appeared to be influenced by the press (best average correlation=0.92, P<.007). Furthermore, web users showed pronounced interest in YouTube videos of an infodemic nature. Finally, the press gave resonance to serious "fake news" on COVID-19, which caused pronounced spikes of interest from web users.

CONCLUSIONS

Our results suggest that the Italian mass media have played a decisive role in spreading the COVID-19 infodemic and addressing netizens' web interest, thus favoring the adoption of terms that are unsuitable for identifying COVID-19. Therefore, the directors of news channels and newspapers should be more cautious, and government dissemination agencies should exert more control over such news stories.

Trends, Uptake, and Predictors of Influenza Vaccination Among Healthcare Practitioners During the COVID-19 Pandemic Flu Season (2020) and the Following Season (2021) in Saudi Arabia

Background

Healthcare practitioners (HCPs) are at high risk of influenza. Seasonal influenza vaccines can reduce influenza-associated morbidity in healthcare settings, but despite mandatory influenza vaccination in the Kingdom of Saudi Arabia, the vaccination uptake rate among HCPs is below expectations. This study investigated vaccination trends from 2017 to 2020 to identify factors affecting vaccination among HCPs during the COVID-19 pandemic flu and subsequent seasons.

Methods

Cross-sectional study among HCPs was conducted in January 2021. A structured questionnaire was shared via social media. Vaccine uptake predictors were identified using descriptive statistics and logistic regression models (p-value 0.05).

Results

A total of 424 HCPs (118 physicians and 306 nurses) completed the questionnaire. Vaccine uptake increased from 2017 to 2019 (45% to 52% to 62%) but fell (to 59%) during the 2020 COVID-19 pandemic flu season. Multivariable analysis indicated participants >40 years old (AOR 3.09, 95% CI 1.64–5.83), female (AOR 1.74, 95% CI 1.13–2.67), non-Saudi (AOR 2.62, 95% CI 1.72–4.01), nurses (AOR 2.70, 95% CI 1.75–4.17), and who possessed accurate knowledge of the flu vaccine efficacy duration (AOR 3.04, 95% CI 1.87–4.94) were more likely to have received the vaccine. However, 79% of HCPs declared their intention to be vaccinated in the 2021 flu season, with participants >40 years old, female (AOR 2.25, 95% CI 1.38–3.68), non-Saudi (AOR 3.79, 95% CI 2.34–6.16), or nurses (AOR 2.94, 95% CI 1.82–4.76) more likely to do so.

Conclusion

Influenza vaccination uptake declined among HCPs during the 2020 flu season compared with the previous season but is expected to increase in the upcoming 2021 season. Nevertheless, the findings are encouraging and indicate increased willingness of HCPs to become vaccinated in the upcoming 2021 season, but coverage could be further increased by policymakers via a comprehensive plan focusing particularly on younger HCPs, Saudis, males, and physicians.

Harnessing the non-specific immunogenic effects of available vaccines to combat COVID-19

No proven remedy is identified for COVID-19 yet. SARS-CoV-2, the viral agent, is recognized by some endosomal and cytosolic receptors following cell entry, entailing innate and adaptive immunity stimulation, notably through interferon induction. Impairment in immunity activation in some patients, mostly elderlies, leads to high mortalities; thus, promoting immune responses may help. BCG vaccine is under investigation to prevent COVID-19 due to its non-specific effects on the immune system. However, other complementary immune-induction methods at early stages of the disease may be needed. Here, the potentially preventive immunologic effects of BCG and influenza vaccination are compared with the immune response defects caused by aging and COVID-19. BCG co-administration with interferon-α/-β, or influenza vaccine is suggested to overcome its shortcomings in interferon signaling against COVID-19. However, further studies are highly recommended to assess the outcomes of such interventions considering their probable adverse effects especially augmented innate immune responses and overproduction of proinflammatory mediators.

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

Background

With a unique influenza season occurring in the midst of a pandemic, there is interest in assessing the role of the influenza vaccine in COVID-19 susceptibility and severity.

Methods

In this retrospective cohort study, patients receiving a laboratory test for COVID-19 were identified. The primary outcome was comparison of positive COVID-19 testing in those who received the influenza vaccine versus those who did not. Secondary end points in patients testing positive for COVID-19 included mortality, need for hospitalization, length of stay, need for intensive care, and mechanical ventilation.

Results

A total of 27,201 patients received laboratory testing for COVID-19. The odds of testing positive for COVID-19 was reduced in patients who received an influenza vaccine compared to those who did not (odds ratio 0.76, 95% CI 0.68-0.86; P < .001). Vaccinated patients testing positive for COVID-19 were less likely to require hospitalization (odds ratio, 0.58, 95% CI 0.46-0.73; P < .001), or mechanical ventilation (odds ratio, 0.45, 95% CI 0.27-0.78; P  = .004) and had a shorter hospital length of stay (risk ratio, 0.76, 95% CI 0.65-0.89; P < .001).

Conclusion

Influenza vaccination is associated with decreased positive COVID-19 testing and improved clinical outcomes and should be promoted to reduce the burden of COVID-19.

Heterologous vaccine interventions: boosting immunity against future pandemics

While vaccines traditionally have been designed and used for protection against infection or disease caused by one specific pathogen, there are known off-target effects from vaccines that can impact infection from unrelated pathogens. The best-known non-specific effects from an unrelated or heterologous vaccine are from the use of the Bacillus Calmette-Guérin (BCG) vaccine, mediated partly through trained immunity. Other vaccines have similar heterologous effects. This review covers molecular mechanisms behind the heterologous effects, and the potential use of heterologous vaccination in the current COVID-19 pandemic. We then discuss novel pandemic response strategies based on rapidly deployed, widespread heterologous vaccination to boost population-level immunity for initial, partial protection against infection and/or clinical disease, while specific vaccines are developed.

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.

COVID-19 vaccine rumors and conspiracy theories: The need for cognitive inoculation against misinformation to improve vaccine adherence

INTRODUCTION

Rumors and conspiracy theories, can contribute to vaccine hesitancy. Monitoring online data related to COVID-19 vaccine candidates can track vaccine misinformation in real-time and assist in negating its impact. This study aimed to examine COVID-19 vaccine rumors and conspiracy theories circulating on online platforms, understand their context, and then review interventions to manage this misinformation and increase vaccine acceptance.

METHOD

In June 2020, a multi-disciplinary team was formed to review and collect online rumors and conspiracy theories between 31 December 2019-30 November 2020. Sources included Google, Google Fact Check, Facebook, YouTube, Twitter, fact-checking agency websites, and television and newspaper websites. Quantitative data were extracted, entered in an Excel spreadsheet, and analyzed descriptively using the statistical package R version 4.0.3. We conducted a content analysis of the qualitative information from news articles, online reports and blogs and compared with findings from quantitative data. Based on the fact-checking agency ratings, information was categorized as true, false, misleading, or exaggerated.

RESULTS

We identified 637 COVID-19 vaccine-related items: 91% were rumors and 9% were conspiracy theories from 52 countries. Of the 578 rumors, 36% were related to vaccine development, availability, and access, 20% related to morbidity and mortality, 8% to safety, efficacy, and acceptance, and the rest were other categories. Of the 637 items, 5% (30/) were true, 83% (528/637) were false, 10% (66/637) were misleading, and 2% (13/637) were exaggerated.

CONCLUSIONS

Rumors and conspiracy theories may lead to mistrust contributing to vaccine hesitancy. Tracking COVID-19 vaccine misinformation in real-time and engaging with social media to disseminate correct information could help safeguard the public against misinformation.

To vaccinate or not to vaccinate; that is the question! (New insights on COVID-19 Vaccination)

AIM

This is a mini-review of the literature; to discuss the obstacles and benefits of vaccination in the era of current pandemic, either the COVID-19 vaccines, which are on their way to be released or the influenza vaccines. There is much debate concerning their effectiveness on ameliorating the severity of the COVID-19 pandemic.

METHODOLOGY

Searching the literature till November 2020 in the PubMed database.

RESULTS

Pathophysiology behind the COVID-19 vaccination obstacles is discussed in detail with future hopes. Influenza vaccination during the debate of the pandemic is also discussed with the most recent guidelines.

CONCLUSIONS

During the COVID-19 pandemic, influenza vaccination is mandatory for all individuals provided no contraindications. Three SARS-CoV-2 vaccines are being released , while FDA approval for monoclonal antibodies for the treatment of at-risk outpatients to lower hospitalization rates is ongoing.

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.

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.

Countries with high deaths due to flu and tuberculosis demonstrate lower COVID-19 mortality: roles of vaccinations

Deaths due to the ongoing COVID-19 pandemic vary (3-1681 deaths/million and mortality rates 0.71-14.54%) and are far greater in some countries compared to others. This observation led us to perform epidemiological analysis, using data in the public domain, to study the correlation of COVID-19 with the prevalence and vaccination strategies for two respiratory pathogens: flu and tuberculosis (TB). Countries showing more than 1000 COVID-19 deaths were selected at three time points during the ongoing pandemic: 17 May, 1 October and 31 December 2020. The major findings of this study that are broadly consistent at all three time points are: First, countries with high flu deaths negatively correlate with COVID-19 deaths/million. Second, TB incidences and deaths negatively correlate with COVID-19 deaths/million. Countries displaying high TB and flu deaths (Nigeria, Ethiopia, Myanmar, Indonesia, India) display lower COVID-19 deaths/million compared to countries with low TB and flu deaths (Italy, Spain, USA, France). Third, countries with greater flu vaccination display lower flu incidences but higher COVID-19 deaths/million and mortality rates. On the other hand, Bacillus Calmette Guerin (BCG) vaccination negatively correlates with Covid-19 deaths/million. Fourth, countries with only BCG, but no flu, vaccination show delayed and lower number of COVID-19 deaths/million compared to countries with flu, but no BCG, vaccination. Fifth, countries with high BCG vaccination coverage as well as high TB deaths display the lowest COVID-19 deaths/million. The implications of this global study are discussed with respect to the roles of respiratory infections and vaccinations in lowering COVID-19 deaths.

Analysis of Epidemiological and Clinical Characteristics of COVID-19 in Northwest Mexico and the Relationship Between the Influenza Vaccine and the Survival of Infected Patients

The first cases of unexplained pneumonia were reported in Wuhan, China, in December of 2019. Later, a novel coronavirus (SARS-CoV-2) was identified as the causal agent of pneumonia. This virus has since spread to more than 180 countries and has been declared a pandemic by the World Health Organization. Herein, we aimed to determine the epidemiological and clinical characteristics of symptomatic patients with coronavirus disease 2019 (COVID-19) and the relationship between the influenza vaccine with a lower risk of severe COVID-19 infection in the state of Sinaloa. We collected demographic and clinical data of 4,040 patients with acute respiratory infections across Sinaloa state hospitals from February 28 to May 15, 2020. The prevalence of COVID-19 among hospitalized patients with respiratory symptoms in Sinaloa showed 45.2% of men were more affected than women (p < 0.001), and people aged 40-49 years were the most affected. The main symptoms of COVID-19 infection were cough and fever (p < 0.001), while hypertension, obesity, and type 2 diabetes were the chronic diseases associated with COVID-19 than non-COVID-19 (p < 0.003). Healthcare workers were most likely to be infected compared to other occupations (p < 0.001). The general lethality rate was 14.1%, and males >62 years were the ones who had a higher lethality rate (p < 0.001); the aforementioned chronic diseases were related to higher lethality of COVID-19 (p < 0.001). Likewise, higher lethality was seen in housewives and patient retirees/pensioners compared with other occupations (p < 0.001). Finally, we found there was a relationship between influenza vaccination and a lower risk of severe COVID-19 infection and mortality (p < 0.001). These findings showed that healthcare workers, men >62 years with chronic diseases, and retired people were most affected. Furthermore, the influenza vaccine could decrease the severeness of COVID-19 cases.

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

BACKGROUND

A possible protective effect of seasonal influenza vaccination against the spread of the COVID-19 epidemic has been suggested.

METHODS

We used publicly available data bases to explore the hypothesis as well as the effect of multiple social and environmental factors in the 20 Italian regions.

RESULTS

Our results suggest that vaccination against seasonal influenza might beneficially impact on incidence and severity of the novel corona virus epidemic. Population density and vehicular traffic were also moderately associated with cumulative incidence of COVID-19. None of the other variables we considered showed an effect on cumulative incidence, case fatality rate or mortality from COVID-19.

CONCLUSIONS

Extending influenza vaccination coverage particularly among the elderly, vulnerable individuals with specific chronic medical conditions, health care workers, and workers in other essential services, early in the upcoming 2020 influenza season, might help reduce the health impact of a second epidemic wave of COVID-19.

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

BACKGROUND

Claims of influenza vaccination increasing COVID-19 risk are circulating. Within the I-MOVE-COVID-19 primary care multicentre study, we measured the association between 2019-20 influenza vaccination and COVID-19.

METHODS

We conducted a multicentre test-negative case-control study at primary care level, in study sites in five European countries, from March to August 2020. Patients presenting with acute respiratory infection were swabbed, with demographic, 2019-20 influenza vaccination and clinical information documented. Using logistic regression, we measured the adjusted odds ratio (aOR), adjusting for study site and age, sex, calendar time, presence of chronic conditions. The main analysis included patients swabbed ≤7 days after onset from the three countries with <15% of missing influenza vaccination. In secondary analyses, we included five countries, using multiple imputation with chained equations to account for missing data.

RESULTS

We included 257 COVID-19 cases and 1631 controls in the main analysis (three countries). The overall aOR between influenza vaccination and COVID-19 was 0.93 (95% CI: 0.66-1.32). The aOR was 0.92 (95% CI: 0.58-1.46) and 0.92 (95% CI: 0.51-1.67) among those aged 20-59 and ≥60 years, respectively. In secondary analyses, we included 6457 cases and 69 272 controls. The imputed aOR was 0.87 (95% CI: 0.79-0.95) among all ages and any delay between swab and symptom onset.

CONCLUSIONS

There was no evidence that COVID-19 cases were more likely to be vaccinated against influenza than controls. Influenza vaccination should be encouraged among target groups for vaccination. I-MOVE-COVID-19 will continue documenting influenza vaccination status in 2020-21, in order to learn about effects of recent influenza vaccination.

Association between seasonal flu vaccination and COVID-19 among healthcare workers

Background

In next fall and winter, SARS-CoV-2 could circulate in parallel with seasonal influenza. The dual epidemics will result in considerable morbidity and mortality; therefore, influenza vaccination may be essential. Recent studies found increased risk of coronavirus in individuals receiving influenza vaccination.

Aims

Our aim is to analyse the association between influenza vaccination and COVID-19 in a population of healthcare workers (HCWs).

Methods

IgG antibodies against SARS-CoV-2 were detected in 3520 HCWs at a large hospital in Northern Italy. For each participant, we collected data on flu immunization status for the last five flu seasons. Logistic regression was used to test associations between seasonal flu vaccination status and a positive serology tests for COVID-19.

Results

During the last five flu seasons, 2492 vaccinations were administered. Serology tests were negative for 3196 (91%) HCWs and residents and only 21 (1%) people had an equivocal test (12.0–15.0 AU/mL). Only 128 (4%) people received a diagnosis of COVID-19, with a positive swab test. No flu vaccinations for the last five flu seasons were specifically associated with diagnosis of COVID-19 or with positive results of serology tests.

Conclusions

Flu vaccinations did not appear to be associated with SARS-CoV-2 infection. Influenza vaccination should continue to be recommended for HCWs and for individuals at increased risk for severe illness from respiratory infection.

Toxicology issues related to the COVID–19 outbreak

In viral pandemics, such as coronavirus disease 2019 (COVID–19), the impact of real-life exposures to multiple toxic stressors that increase immune system dysfunction is followed by the main pandemic-associated virus (SARS–CoV–2, for COVID–19) exploiting the dysfunctional immune system to trigger a chain of events ultimately leading to the pandemic (COVID–19). Thus pandemics have two main components: virology (focused on the virus) and toxicology (focused on the toxic stressors).

The present chapter will focus mainly on the immune system toxicology component. It identifies the factors shown most frequently to increase immune system dysfunction, and then addresses vaccine toxicology in detail. The chapter concludes by reviewing two types of treatments: immune-augmenting and immune-strengthening. The immune-augmenting approaches are virology-centric (e.g., quarantine, face masks, repurposed antiviral treatments, vaccines, etc.), and the immune-strengthening approaches are toxicology-centric (e.g., eliminating the factors that contribute to immune system dysfunction, and adding factors that increase immune system health).

The association of previous influenza vaccination and coronavirus disease-2019

Studies have shown similarities in the structure of influenza and coronaviruses, in their binding receptors and in patterns of immune responses; and that influenza vaccine can induce cross-immunity. We examined the association of previous influenza vaccination and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, resulting in coronavirus disease-2019 (COVID-19), among 715,164 members of a health maintenance organization. In a multivariate regression model, the odds ratios for SARS-CoV-2 infection among individuals vaccinated for influenza in 2018-2019, 2019-2020, and in both seasons, compared to non-vaccinated individuals, were 0.82 (95% CI 0.68-0.99, p = .048), 0.79 (95% CI 0.67-0.98, p = .005), and 0.76 (95% CI 0.61-0.97, p = .004), respectively. Based on our findings, administration of influenza vaccine before the influenza season is highly recommended to reduce the burden of influenza, which is critical in scenarios of outbreaks of both influenza and SARS-CoV-2 infections, and also regarding its association with reduced rate of COVID-19.

Obesity Increases the Severity and Mortality of Influenza and COVID-19: A Systematic Review and Meta-Analysis

Since December 2019, COVID-19 has aroused global attention. Studies show the link between obesity and severe outcome of influenza and COVID-19. Thus, we aimed to compare the impacts of obesity on the severity and mortality of influenza and COVID-19 by performing a meta-analysis. A systematic search was performed in MEDLINE, EMASE, ClinicalTrials.gov, and Web of Science from January 2009 to July 2020. The protocol was registered onto PROSPERO (CRD42020201461). After selection, 46 studies were included in this meta-analysis. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were analyzed. We found obesity was a risk factor for the severity and mortality of influenza (ORsevere outcome = 1.56, CI: 1.28-1.90; ORmortality = 1.99, CI: 1.15-3.46). For COVID-19, obesity was a significant risk factor only for severe outcome (OR = 2.07, CI: 1.53-2.81) but not for mortality (OR = 1.57, CI: 0.85-2.90). Compared with obesity, morbid obesity was linked with a higher risk for the severity and mortality of both influenza (OR = 1.40, CI: 1.10-1.79) and COVID-19 (OR = 3.76, CI: 2.67-5.28). Thus, obesity should be recommended as a risk factor for the prognosis assessment of COVID-19. Special monitoring and earlier treatment should be implemented in patients with obesity and COVID-19.

Impact of catch-up vaccination on aluminum exposure due to new laws and post social distancing

BACKGROUND

The COVID-19 pandemic has placed significant stressors on the medical community and on the general public. Part of this includes patients skipping well-child visits to reduce risk of exposure to SARS-CoV-2 virus. Published estimates of the duration of whole-body aluminum (Al) toxicity from vaccines in infants from birth to six months indicate that CDC's recommended vaccination schedule leads to unacceptably long periods of time in which infants are in aluminum toxicity (as measured by %AlumTox).

METHODS

We utilize these established clearance and accumulation models to calculate expected per-body-weight whole-body toxicity of aluminum from vaccines considering for children of all ages under CDC's Catch-Up schedule from birth to ten years, assuming social distancing for 6 months. Our updated Pediatric Dose Limit (PDL) model assumes a linear improvement in renal function from birth to two years.

RESULTS

Our results indicate that due diligence in considering alternative spacing and use of non-aluminum containing vaccines when possible will reduce whole body toxicity and may reduce risk of morbidity associated with exposure to aluminum.

CONCLUSIONS

While reduction or elimination of aluminum exposure from all sources is always a good idea, our results indicate that careful consideration of expected aluminum exposures during regular and Catch-Up vaccination is found to be especially important for infants and children below 2 years of age. We urge caution in the mass re-starting of vaccination under CDC's Catch-Up schedule for children under 12 months and offer alternative strategies to minimize per-day/week/month exposure to aluminum hydroxide following the COVID-19 period of isolation.

2020-2021 AMMI Canada guidance on the use of antiviral drugs for influenza in the setting of co-circulation of seasonal influenza and SARS-CoV-2 viruses in Canada

We provide an update to the Association of Medical Microbiology and Infectious Disease Canada foundation guidance for the upcoming 2020-2021 influenza season in Canada. Important issues for this year include the implications of co-circulation of SARS-CoV-2, the role of diagnostic testing, and a restatement of dosing and administration recommendations for neuraminidase inhibitors in various age groups and underlying health conditions. Although peramivir and baloxivir are now licensed in Canada, neither is currently marketed, so this guidance focuses on further optimizing the use of oseltamivir and zanamivir.