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

Abstract

Introduction Recently, several single center studies have suggested a protective effect of the influenza vaccine against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This study utilizes a continuously updated Electronic Medical Record (EMR) network to assess the possible benefits of influenza vaccination mitigating critical adverse outcomes in SARS-CoV-2 positive patients from 56 healthcare organizations (HCOs). Methods The de-identified records of 73,346,583 patients were retrospectively screened. Two cohorts of 37,377 patients, having either received or not received influenza vaccination six months–two weeks prior to SARS-CoV-2 positive diagnosis, were created using Common Procedural Terminology (CPT) and logical observation identifiers names and codes (LOINC) codes. Adverse outcomes within 30, 60, 90, and 120 days of positive SARS-CoV-2 diagnosis were compared between cohorts. Outcomes were assessed with stringent propensity score matching including age, race, ethnicity, gender, hypertension, diabetes, hyperlipidemia, chronic obstructive pulmonary disease (COPD), obesity, heart disease, and lifestyle habits such as smoking. Results SARS-CoV-2-positive patients who received the influenza vaccine experienced decreased sepsis (p<0.01, Risk Ratio: 1.361–1.450, 95% CI:1.123–1.699, NNT:286) and stroke (p<0.02, RR: 1.451–1.580, 95% CI:1.075–2.034, NNT:625) across all time points. ICU admissions were lower in SARS-CoV-2-positive patients receiving the influenza vaccine at 30, 90, and 120 days (p<0.03, RR: 1.174–1.200, 95% CI:1.003–1.385, NNT:435), while approaching significance at 60 days (p = 0.0509, RR: 1.156, 95% CI:0.999–1.338). Patients who received the influenza vaccine experienced fewer DVTs 60–120 days after positive SARS-CoV-2 diagnosis (p<0.02, RR:1.41–1.530, 95% CI:1.082–2.076, NNT:1000) and experienced fewer emergency department (ED) visits 90–120 days post SARS-CoV-2-positive diagnosis (p<0.01, RR:1.204–1.580, 95% CI: 1.050–1.476, NNT:176). Conclusion Our analysis outlines the potential protective effect of influenza vaccination in SARS-CoV-2-positive patients against adverse outcomes within 30, 60, 90, and 120 days of a positive diagnosis. Significant findings favoring influenza vaccination mitigating the risks of sepsis, stroke, deep vein thrombosis (DVT), emergency department (ED) & Intensive Care Unit (ICU) admissions suggest a potential protective effect that could benefit populations without readily available access to SARS-CoV-2 vaccination. Thus further investigation with future prospective studies is warranted.

Effect and Tolerability of a Nutritional Supplement Based on a Synergistic Combination of β-Glucans and Selenium- and Zinc-Enriched Saccharomyces cerevisiae (ABB C1®) in Volunteers Receiving the Influenza or the COVID-19 Vaccine: A Randomized, Double-Blind, Placebo-Controlled Study

“…At 30, 60, 90, and 120 days of SARS-CoV-2-positive diagnosis, patients in the cohort that received the influenza vaccine showed a significantly reduced risk for all outcomes. The authors of the study suggest that influenza vaccination may exert a potential protective effect that could benefit populations without ready access to COVID-19 vaccination [36]. In the present study, none of the patients in the COVID-19 group received a diagnosis of SARS-CoV-2 infection.…”

“…This mechanism has been demonstrated in the protective effect of BCG vaccination of human malaria infection [35]. The potential benefit of influenza vaccination mitigating critical outcomes in patients with SARS-CoV-2 infection, such as sepsis, stroke, deep vein thrombosis, and emergency and ICU admissions, was analyzed in a retrospective analysis of two cohorts of 37,377 patients, having either received or not received influenza vaccination between 6 months and 2 weeks prior to COVID-19 infection [36]. Data were analyzed using a strict propensity score matching procedure adjusted by age, race, gender, ethnicity, hypertension, hyperlipidemia, diabetes, obesity, heart disease, chronic obstructive pulmonary disease, and smoking.…”

COVID‐19 coagulopathies: Human blood proteins mimic SARS‐CoV‐2 virus, vaccine proteins and bacterial co‐infections inducing autoimmunity

“…Vaccination against SARS‐CoV‐2 as well as against recognized coinfections such as Streptococci, Haemophilus , and influenza virus should decrease risk of coagulopathies by preventing bystander or complementary co‐infections, just as they decrease risk of severe COVID‐19 in general. [ 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 ] Additionally, the results reported here may provide insight into the causes of menstruation alterations reported by some women following SARS‐CoV‐2 vaccination. [ 112 ] Finally, the present work has implications for future SARS‐CoV‐2 vaccine design, implying that whole virus SARS‐CoV‐2 vaccines may present an extraordinary risk of inducing coagulopathies compared with the mRNA, peptide, or subunit vaccines because of the very large number of blood protein mimics present; however removing molecular mimicry regions from SARS‐CoV‐2 mRNAs, proteins and their virus vectors may significantly improve vaccine safety.…”

Influenza Vaccination Programs for Healthcare Personnel: Organizational Issues and Beyond

“…However, more studies are needed to comprehensively evaluate cost-effectiveness. Finally, a recent study of two cohorts of 37,377 patients with SARS-CoV-2 infection found that influenza-vaccinated patients had significantly less often sepsis, stroke, deep vein thrombosis, emergency department and intensive care unit admissions which indicate a potential protective effect against SARS-CoV-2 [ 30 ]. Further investigation is needed.…”