Risk of Guillain-Barré Syndrome Following Recombinant Zoster Vaccine in Medicare Beneficiaries

IMPORTANCE

Guillain-Barré syndrome can be reported after vaccination. This study assesses the risk of Guillain-Barré syndrome after administration of recombinant zoster vaccine (RZV or Shingrix), which is administered in 2 doses 2 to 6 months apart.

OBJECTIVE

Use Medicare claims data to evaluate risk of developing Guillain-Barré syndrome following vaccination with zoster vaccine.

DESIGN, SETTING, AND PARTICIPANTS

This case series cohort study included 849 397 RZV-vaccinated and 1 817 099 zoster vaccine live (ZVL or Zostavax)-vaccinated beneficiaries aged 65 years or older. Self-controlled analyses included events identified from 2 113 758 eligible RZV-vaccinated beneficiaries 65 years or older. We compared the relative risk of Guillain-Barré syndrome after RZV vs ZVL, followed by claims-based and medical record-based self-controlled case series analyses to assess risk of Guillain-Barré syndrome during a postvaccination risk window (days 1-42) compared with a control window (days 43-183). In self-controlled analyses, RZV vaccinees were observed from October 1, 2017, to February 29, 2020. Patients were identified in the inpatient, outpatient procedural (including emergency department), and office settings using Medicare administrative data.

EXPOSURES

Vaccination with RZV or ZVL vaccines.

MAIN OUTCOMES AND MEASURES

Guillain-Barré syndrome was identified in Medicare administrative claims data, and cases were assessed through medical record review using the Brighton Collaboration case definition.

RESULTS

Amongst those who received RZV vaccinees, the mean age was 74.8 years at first dose, and 58% were women, whereas among those who received the ZVL vaccine, the mean age was 74.3 years, and 60% were women. In the cohort analysis we detected an increase in risk of Guillain-Barré syndrome among RZV vaccinees compared with ZVL vaccinees (rate ratio [RR], 2.34; 95% CI, 1.01-5.41; P = .047). In the self-controlled analyses, we observed 24 and 20 cases during the risk and control period, respectively. Our claims-based analysis identified an increased risk in the risk window compared with the control window (RR, 2.84; 95% CI, 1.53-5.27; P = .001), with an attributable risk of 3 per million RZV doses (95% CI, 0.62-5.64). Our medical record-based analysis confirmed this increased risk (RR, 4.96; 95% CI, 1.43-17.27; P = .01).

CONCLUSIONS AND RELEVANCE

Findings of this case series cohort study indicate a slightly increased risk of Guillain-Barré syndrome during the 42 days following RZV vaccination in the Medicare population, with approximately 3 excess Guillain-Barré syndrome cases per million vaccinations. Clinicians and patients should be aware of this risk, while considering the benefit of decreasing the risk of herpes zoster and its complications through an efficacious vaccine, as risk-benefit balance remains in favor of vaccination.

The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate

BACKGROUND

The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals.

METHODS

Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological characteristics of vascular and renal tissues were determined.

RESULTS

GFR averaged 342 ± 99 mL min(-1) and ERPF 1252 ± 305 mL min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39 ± 2 mmHg and renal venous pressure 32 ± 4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively.

CONCLUSION

In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP, which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP.

A mathematical model of the mechanical link between shortening of the cardiomyocytes and systolic deformation of the left ventricular myocardium

BACKGROUND

Left ventricular myocytes are arranged in a complex three-dimensional mesh. Since all myocytes contract approximately to the same degree, mechanisms must exist to enable force transfer from each of these onto the framework as a whole, despite the transmural differences in deformation strain. This process has hitherto not been clarified in detail.

OBJECTIVE

To present a geometrical model that establishes a mechanical link between the three-dimensional architecture and the function of the left ventricular myocardium.

METHODS

The left ventricular equator was modeled as a cylindrical tube of deformable but incompressible material, composed of virtual cardiomyocytes with known diastolic helical and transmural angles. By imposing reference circumferential, longitudinal, and torsional strains onto the model, we created a three-dimensional deformation field to calculate passive shortening of the myocyte surrogates. We tested two diastolic architectures: 1) a simple model with longitudinal myocyte surrogates in the endo- and epicardium, and circular ones in the midwall, and 2) a more accurate architecture, with progressive helical angle distribution varying from -60° in the epicardium to 60° in the endocardium, with or without torsion and transmural cardiomyocyte angulation.

RESULTS

The simple model caused great transmural unevenness in cardiomyocyte shortening; longitudinal surrogates shortened by 15% at all depths equal to the imposed longitudinal strain, whereas circular surrogates exhibited a maximum shortening of 23.0%. The accurate model exhibited a smooth transmural distribution of cardiomyocyte shortening, with a mean (range) of 17.0 (13.2-20.8)%. Torsion caused a shortening of 17.0 (15.2-18.9)% and transmural angulation caused a shortening of 15.2 (12.4-18.2)%. Combining the effects of transmural angulation and torsion caused a change of 15.2 (13.2-16.5)%.

CONCLUSION

A continuous transmural distribution of the helical angle is obligatory for smooth shortening of the cardiomyocytes, but a combination of torsional and transmural angulation changes is necessary to execute systolic mural thickening whilst keeping shortening of the cardiomyocytes within its physiological range.

The effect of intravesically administered Cetiprin on bladder spasms after transurethral resection of the prostate. A double-blind randomized study

A double-blind study of the short-term effects of intravesically administered emepronium bromide (Cetiprin) versus placebo on bladder spasms after transurethral prostatectomy was done in 40 male patients. In the Cetiprin group there was a significant decline in the need for analgesia, and significantly fewer catheter problems. The use of intravesically instilled Cetiprin is recommended only in cases of severe postoperative bladder spasms.

A conservative approach to the management of blunt renal trauma. Results of a follow-up study

Forty patients with abnormal radiological findings after blunt renal trauma are presented. A conservative approach to treatment led to only 3 nephrectomies in patients with renal pedicle injury and to surgery in another 4 patients; in only one case was the function of the injured kidney reduced. At follow-up 1 to 5 years later, 4 patients had mild subjective symptoms but the objective findings were few and insignificant. However, since serious sequelae (e.g. hypertension) may follow renal trauma, we suggest that these patients should be seen one year after injury for clinical examination, including renography and measurement of blood pressure.

Urological septicemia. A retrospective study

In order to investigate the clinical course and outcome of septicemia in urological patients, data were collected retrospectively from all patients admitted to a specialized urological department, in whom positive blood cultures were drawn. During a 5-year period 91 patients were registered with urosepsis corresponding to an incidence of 1.2%. In non-iatrogenic urosepsis due to ureteral obstruction women dominated over men, however, in iatrogenic disease--after investigative manoeuvres as well as after surgery--men by large dominated the material. Gram-negative bacteria were responsible for almost 75% of the septicemias and for 99% of the cases where septic shock was present. Where a urinary infection was demonstrated prior to septicemia (45%- identical bacteria were subsequently found in the blood, whether the focus had been successfully treated or not. Septic shock developed in 20 of the patients of whom 3 died. This overall mortality of 3% occurred only in patients with comcomitant serious disease. In general the course of septicemia was benign and the complication rate low. It is concluded that in urological patients septicemia is a less serious problem than in gastroenterological patients. The possible explanation for this is discussed in relation to the more discrete diagnostic and therapeutical procedures in the urological clinic.

Quantitative evaluation of testicular biopsies before and after operation for varicocele

Testicular biopsies and semen samples were examined before and approximately 1 year after operation for varicocele in 39 men. Two men were excluded because of Sertoli-cell-only syndrome. Of the remaining 37, 22 were operated upon for infertility. The testicular biopsies were quantitated with the score count method. The operation for varicocele significantly improved the testicular tissue. THe numbers of tubuli obtaining a high score increased and the biopsy mean scores also increased significantly. However, few testes became perfectly normal. The duration or the size of the varicocele apparently has little effect upon the state of the testicular tissue or the change in it after operation.

Quantitative evaluation of testicular biopsies in varicocele

Testicular biopsies from 81 patients with varicocele were evaluated by the score count method. Thirty-two patients sought treatment for infertility. Bilateral biopsies were performed in 47. Spermatogenesis was generally reduced in patients with varicocele, but there was no difference between the right and left tests. The testicular biopsy mean score correlated significantly with the total sperm count. There was no correlation between the size of the varicocele and the reduction in spermatogenesis. Although varicocele is nearly always left-sided, its mechanism of action must involve both testes. This mechanism is still unknown.

Does the oesophageal balloon compress oesophageal varices?

The pressure transmitted to the oesophageal wall was measured in 3 patients with bleeding oesophageal varices controlled by balloon tamponade. The pressure transmitted was considerably lower than the pressure inflated, and all patients suffered retrosternal pain when the transmitted pressure rose to 40 mm Hg. Furthermore, the diameters of oesophageal balloons of 23 Sengstaken-Blakemore tubes (Rüsch) were measured at increasing inflation pressure. The compliance was very high. All balloons bulged at median inflation pressures of 75 mm Hg, and the pressures fell to a median of 55 mm Hg unaffected by further inflations. The diameter at 40 mmHg was 27.3 mm. In the light of these observations it remains still to be explained how the oesophageal balloon of the Sengstaken-Blakemore tube effects haemostasis in bleeding oesophageal varices.

Passage of barium meal through esophagus in patients with balloon tamponade of esophageal varices

Four patients in different states of consciousness in treatment with Sengstaken-Blakemore tube were given a barium meal. In every case the contrast medium passed the balloons and was cleared from the upper esophagus in less than four minutes, and none of it was aspirated to the bronchi.