Bell's palsy and influenza(H1N1)pdm09 containing vaccines: A self-controlled case series

Association of Influenza Vaccination With Risk of Bell Palsy Among Older Adults in Taiwan

Importance

Annual administration of the influenza vaccine (fluVc) is currently the most effective method of preventing the influenza virus in older adults. However, half of adults older than 65 years remain unvaccinated in Taiwan, possibly because of concern about adverse events, such as Bell palsy (BP). Currently, studies on the association between fluVc and risk of BP are inconsistent.

Objective

To determine whether the incidence of BP increases following fluVc in older adults.

Design, Setting, and Participants

A self-controlled case series study design was used. Days 1 through 7, days 8 through 14, days 15 through 30, and days 31 through 60 following fluVc were identified as risk intervals, and days 61 through 180 were considered the control interval. A total of 4367 vaccinated individuals aged 65 years or older who developed BP within 6 months following fluVc were enrolled. Population-based retrospective claims data were obtained between 2010 and 2017; data were analyzed from April 2022 through September 2022.

Exposure

Government-funded seasonal fluVc.

Main Outcomes and Measures

The outcome of interest was BP onset in risk intervals compared with control intervals. Three or more consecutive diagnoses of BP within 60 days following fluVc were used as the definition of a patient with BP. Poisson regression was used to analyze the incidence rate ratio (IRR) of risk intervals compared with control intervals.

Results

In total, 13 261 521 patients who received the fluVc were extracted from the National Health Insurance Research Database in Taiwan from January 1, 2010, to December 31, 2017. Of those, 7 581 205 patients older than 65 years old met the inclusion criteria. The number of patients with BP diagnosed within 6 months following fluVc enrolled for risk analysis was 4367 (mean [SD] age, 74.19 [5.97] years; 2349 [53.79%] female patients). The incidence rate of BP among all observed fluVc older adults was 57.87 per 100 000 person-years. The IRRs for BP on days 1 through 7, days 8 through 14, and days 15 through 30 were 4.18 (95% CI, 3.82-4.59), 2.73 (95% CI, 2.45-3.05), and 1.67 (95% CI, 1.52-1.84), respectively. However, there was no increase during days 31 through 60 (IRR, 1.06; 95% CI, 0.97-1.16). The postvaccination risk of BP was consistent across all subgroups stratified by sex, age group, and baseline conditions.

Conclusions and Relevance

The present self-controlled case series indicated that the risk of BP in individuals older than 65 years increased within the first month, especially within the first week, following fluVc. But overall, the adverse event rate of BP was low, and considering the morbidity and mortality of influenza infection, the benefits of fluVc still outweigh the risks.

Risk of peripheral facial palsy following parenteral inactivated influenza vaccination in the elderly Chinese population

Background

Concern about the risk of peripheral facial palsy (PFP) following vaccination is one reason for hesitancy in influenza vaccination. However, the association between the flu vaccine and PFP is still controversial, and further evidence is urgently needed.

Methods

This self-controlled case series study evaluated PFP risk following inactivated influenza vaccine in the elderly using a large linked database in Ningbo, China. Relative incidence ratios (RIRs) and 95% confidence intervals (CIs) estimated using conditional Poisson regression were utilized to determine whether the risk of PFP was increased after vaccination.

Results

This study included 467 episodes, which occurred in 244 females and 220 males. One hundred twenty-four episodes happened within 1-91 days after vaccination, accounting for 26.7%. The adjusted RIRs within 1-30 days, 31-60 days, 61-91 days, and 1-91 days after influenza vaccination were 0.95 (95% CI 0.69-1.30), 1.08 (95% CI 0.78-1.49), 1.01 (95% CI 0.70-1.45), and 1.00 (95% CI 0.81-1.24), respectively. Similar results were found in subgroup analyses and sensitivity analyses.

Conclusions

Influenza vaccination does not increase PFP risk in the elderly population. This finding provides evidence to overcome concerns about facial paralysis after influenza vaccination.

Long-term Outcome After Acute Peripheral Facial Palsy

PURPOSE

To analyze long-term outcomes in a large cohort of patients with acute peripheral facial palsy (APFP).

METHODS

Hospital-based, cross-sectional study. Data were abstracted from the electronic medical record. Time to recovery was assessed with Kaplan-Meier survival analyses. Binary logistic regression analysis was used to identify factors associated with outcome.

RESULTS

Three hundred seventy-two patients with APFP seen at a tertiary hospital between February 2015 and March 2021 were analyzed. Seasonal variation of APFP peaked in the early fall (September 29) and had a peak-to-low ratio of 1.36 (R 2 = 0.329, p < 0.001). Patients who tested positive for Lyme disease (10%) had an earlier peak (July 16) compared with those who were negative (October 15). Eighty-seven percent of patients had complete recovery (averaging 64 ± 61 days). Patients, with higher House-Brackmann (H-B) grades at presentation took longer to recover, were more likely to have aberrant regeneration and had lower final rates of recovery compared with those with lower H-B grades (χ 2 = 12.03, p < 0.001). Of the patients with residual palsies, 70% had evidence of aberrant regeneration, and nearly half of those had hemifacial spasm.

CONCLUSIONS

Most patients with APFP achieve complete recovery within 1 year, including those positive for Lyme. More severe palsy at presentation portends a worse outcome.

Can COVID-19 Cause Peripheral Facial Nerve Palsy?

The aim of our study is to evaluate the relationship between peripheral facial paralysis and the patients who had a contact with a coronavirus disease 2019 (COVID-19) patient or had COVID-19. Patients with a history of contact with a COVID-19 patient or having COVID-19 disease, who were admitted to the emergency department for peripheral facial paralysis in the last 6 months, were included in the study. Facial paralysis grade at first presentation, treatment modality, treatment duration, post-treatment facial paralysis grade, and additional findings were analyzed. A total of 34 patients, 20 females and 14 males, were included into the study. Nasal-oropharyngeal reverse transcriptase-polymerase chain reaction (RT-PCR) was test taken from patients with a history of contact, and patients having COVID-19 disease were determined as positive in 5 and 3 patients, respectively. Peripheral facial paralysis was detected as an initial finding in 5 of these 8 patients, and paralysis developed in 7-12 days after the diagnosis of the COVID-19 disease in the remaining 3 patients. The grade of first admission paralysis did not change in one patient in the (+) group, while improvement was observed in all patients in the (−) group. Neuroinvasive potential of COVID-19 in the central and peripheral nervous system was reported in current literature. Our study indicates peripheral facial palsy can also be encountered during the clinical course of COVID-19 and should be considered a finding of this disease.

Bell's palsy in a pediatric patient with hyper IgM syndrome and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Bell's palsy is an acute facial paralysis with known association to viral infections. We describe a medically complex 6-year-old male with hyper IgM syndrome who presented with unilateral facial droop and positive SARS-CoV-2 RT-PCR. This is the first reported pediatric case of Bell's palsy in the setting of SARS-CoV-2 infection.

Facial Paralysis Following Influenza Vaccination: A Disproportionality Analysis Using the Vaccine Adverse Event Reporting System Database

Background and Objective

Several cases of facial paralysis have been reported following influenza vaccination; however, recent surveillance studies have not shown an increased risk. In this study, we analyzed the vaccine adverse event reporting system (VAERS) data to determine whether the facial paralysis reporting rate is higher in those who received influenza vaccination compared with those who received other vaccines.

Methods

We evaluated reports of facial paralysis in people who received influenza vaccination during January 2015 to October 2019 using Medical Dictionary for Regulatory Activities Preferred Terms. A disproportionality analysis was performed to determine the proportional reporting ratio (PRR), Chi-square statistic, and reporting odds ratio (ROR) with 95% confidence interval (CI). The demographic and clinical characteristics of the cases were also analyzed.

Results

Two hundred fifty cases of facial paralysis following influenza vaccination were reported during the study period. The median age of the patients was 45 (interquartile range, 30–57) years; 132 (52.8%) patients were females. The majority of the patients received the injected trivalent or quadrivalent seasonal influenza vaccine by intramuscular route. The PRR, Chi-square statistic, and ROR (95% CI) was 2.44, 122.32, and 2.44 (2.08–2.88), respectively; on excluding cases involving concomitant paresis/paralysis of limbs or Guillain–Barre syndrome, the disproportionality statistics were 2.30, 89.37, and 2.30 (1.93–2.75), respectively.

Conclusions

Our study shows increased reporting of facial paralysis following influenza vaccination as compared with other vaccines. Considering the inherent limitations of the VAERS database analysis, and the fact that disproportionality measures only indicate the presence of a signal, our study findings need to be explored in well-designed prospective pharmacoepidemiologic studies.

Challenges in evaluating post-licensure vaccine safety: observations from the Centers for Disease Control and Prevention

Introduction: Vaccination is one of the most successful and cost-effective public health interventions. Although vaccines undergo extensive safety and efficacy evaluations prior to licensure, vaccine safety assessment post-licensure is essential for detecting rare and longer-term adverse events (AEs) and maintaining public confidence in vaccines and recommended immunization programs. Despite the proven effect of vaccines to save lives and prevent disease and overwhelming evidence of vaccines' safety and societal benefit, like any drug, no vaccine can be considered as completely safe and completely effective. New vaccines continue to be introduced and require rapid safety assessment post-licensure through pharmacovigilance reports as well as epidemiologic studies to investigate any potential safety signals.Areas covered: We discuss selected challenges for conducting pharmacovigilance and epidemiologic studies of AEs after vaccination in the United States using the post-licensure safety surveillance infrastructure of the Centers for Disease Control and Prevention (CDC).Expert opinion: The availability of specific post-licensure surveillance systems to monitor and study AEs after vaccination, such as the Vaccine Adverse Event Reporting System, the Vaccine Safety Datalink, and the Clinical Immunization Safety Assessment Project, each with its unique set of strengths and limitations, provide a harmonized and supportive approach to meet several of these barriers.