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.

The influence of SARS-CoV-2 vaccination on post-operative outcomes in microsurgery patients.

BACKGROUND: The healthcare industry's efforts to immunize the global community against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have been unprecedented. Given the fast-tracking of the novel vaccine, its short- and long-term medical implications remain largely to-be-determined in most patient populations. This study aims to analyze 90-day post-operative outcomes in microsurgical patients, who have received or not received SARS-CoV-2-vaccination, using a continuously updated federated electronic medical record network (TriNetX Inc, Cambridge, MA). METHODS: After screening 70 million de-identified records, 16,799 microsurgery patients aged 18-99 meeting medical coding criteria were allocated into two cohorts. Cohort One received SARS-CoV-2-vaccination prior to undergoing microsurgery whereas Cohort Two did not. Two equally sized cohorts, totaling 818 patients were created after propensity score matching for characteristics including: age, race, ethnicity, smoking, hypertension, heart disease, diabetes, obesity, chronic obstructive pulmonary disease, and history of SARS-CoV-2 exposure. Postoperative outcomes within 30-, 60-, and 90-days of microsurgery were analyzed. RESULTS: Patients who were SARS-CoV-2-immunized experienced significantly lower (p < .01) surgical site infections (Absolute Risk Reduction (ARR)[95%CI]) = (3.79%-5.36% [0.84-8.54]) ICU admission (9.47%-9.82%[5.45-13.88]), generalized infections (7.68%-9.92%[3.15-14.64]), and hospitalizations (28.48%-32.57%[20.99-40.13]) within 30-, 60-, and 90-days of microsurgery. Additionally, SARS-CoV-2-vaccinated patients also experienced significantly less flap failure (2.49%[0.97-4.02]) and death (2.46%[0.96-3.97]) within 30- and 60-days post-operatively. CONCLUSION: Our analysis examines the potential protective effect of SARS-CoV-2-vaccination in microsurgical patients. Limitations include the retrospective nature of this analysis and the inherent reliance on medical coding. Future prospective studies are warranted to better understand if in fact pre-operative SARS-CoV-2-vaccination has the potential to protect against post-operative microsurgery outcomes.

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

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.