Effect of BTN162b2 and CoronaVac boosters on humoral and cellular immunity of individuals previously fully vaccinated with CoronaVac against SARS-CoV-2: A longitudinal study.

BACKGROUND: It is essential to know about immune response levels after booster doses of the two different types of vaccines, mRNA, and the inactivated, currently used against COVID-19. For this purpose, we aimed to determine the effects of BNT162b2 (BNT) and CoronaVac (CV) boosters on the humoral and cellular immunity of individuals who had two doses of CV vaccination. METHODS: The study was conducted in three centers (Koc University Hospital, Istanbul University Cerrahpasa Hospital, and Istanbul University, Istanbul Medical School Hospital) in Istanbul, Turkey. Individuals who had been previously immunized with two doses of CV and no history of COVID-19 were included. The baseline blood samples were collected 3-5 months after the second dose of CV. Follow-up blood samples were taken 1 and 3 months after administration of third doses of CV, or one dose of BNT boosters. Neutralizing antibody titers were measured by plaque reduction assay. The CD4+ T cell, CD8+ T cell, effector CD4+CD38+CD69+ T cell, and effector CD8+CD38+CD69+ T cell ratios were determined by flow cytometry. The intracellular IFN-γ and IL-2 responses were measured by ELISpot assay. RESULTS: We found a 3.38-fold increase in neutralizing antibody geometric mean titers (NA GMT, 78.69) 1 month after BNT booster and maintained at the third month (NA GMT, 80). Nevertheless, in the CV booster group, significantly lower NA GMT than BNT after 1 month and 3 months were observed (21.44 and 28.44, respectively) (p < .001). In the ELISpot assay, IL-2 levels after BNT were higher than baseline and CV booster (p < .001) while IFN-γ levels were significantly higher than baseline (p < .001). The CD8+CD38+CD69+ and CD4+CD38+CD69+ T cells were stimulated predominantly in the third month of the BNT boosters. CONCLUSION: The neutralizing antibody levels after 3 months of the BNT booster were higher than the antibody levels after CV in fully vaccinated individuals. On the contrary, ratio of the effector T cells increased along with greater IFN-γ activation after BNT booster. By considering the waning immunity, we suggest a new booster dose with BNT for the countries that already had two doses of primary CV regimens.

Hyponatremia Is Predictive of HSV-1 Encephalitis among Patients with Viral Encephalitis.

Encephalitis is an inflammatory process involving the brain parenchyma associated with neurologic dysfunction. The main causes of infectious encephalitis are viruses, including Herpes simplex virus type 1 (HSV-1). As the mortality rate of HSV-1 encephalitis could be reduced with early acyclovir treatment, it is imperative to distinguish HSV-1 encephalitis from other type of viral encephalitis as early as possible. However, sophisticated methods for definitive diagnosis of HSV-1 encephalitis are not readily available. We aimed to explore distinctive clinical and laboratory features of HSV-1 encephalitis. All of the adult patients with viral encephalitis hospitalized between 2011-2017 were enrolled, including 16 patients with HSV-1 encephalitis and 51 patients non-HSV-1 viral encephalitis. Determination of viruses in cerebrospinal fluid was performed by PCR tests. Female sex, hyponatremia, and abnormalities in MRI were independently associated with HSV-1 encephalitis (p < 0.05 for each). In particular, hyponatremia (< 135 mEq/L) was found in nine patients with HSV-1 encephalitis (56.3%) and 10 patients with non-HSV-1 viral encephalitis (19.6%) (p = 0.005). As serum sodium is determined easily and quickly in clinical practice, the presence of hyponatremia among patients with viral encephalitis could be helpful for the early diagnosis of HSV-1 encephalitis before cerebrospinal fluid PCR results were available. Moreover, the presence of positive finding in MRI could further support the diagnosis. This is the first study that compared the serum sodium levels among patients between HSV-1 and non-HSV-1 viral encephalitis. We thus propose the diagnostic value of hyponatremia for HSV-1 encephalitis.

Comparison of the Clinical and Laboratory Findings and Outcomes of Hospitalized COVID-19 Patients Who Were Either Fully Vaccinated with Coronavac or Not: An Analytical, Cross Sectional Study.

COVID-19 vaccines are highly protective against severe disease; however, vaccine breakthrough infections resulting in hospitalization may still occur in a small percentage of vaccinated individuals. We investigated whether the clinical and microbiological features and outcomes were different between hospitalized COVID-19 patients who were either fully vaccinated with Coronovac or not. All hospitalized COVID-19 patients who had at least one dose of Coronavac were included in the study. The oldest unvaccinated patients with comorbidities, who were hospitalized during the same period, were chosen as controls. All epidemiologic, clinical and laboratory data of the patients were recorded and compared between the fully vaccinated and unvaccinated individuals. There were 69 and 217 patients who had been either fully vaccinated with Coronavac or not, respectively. All breakthrough infections occurred in the first 3 months of vaccination. Fully vaccinated patients were older and had more comorbidities than unvaccinated patients. There were minor differences between the groups in symptoms, physical and laboratory findings, anti-spike IgG positivity rate and level, the severity of COVID-19, complications, and clinical improvement rate. The mortality rate of fully vaccinated patients was higher than the mortality rate in unvaccinated patients in univariate analysis, which was attributed to the fact that vaccinated patients were older and had more comorbidities. The severity and clinical outcomes of hospitalized patients with breakthrough COVID-19 after Coronavac vaccination were similar to those of unvaccinated patients. Our findings suggest that the immune response elicited by Coronovac could be insufficient to prevent COVID-19-related severe disease and death within 3 months of vaccination among elderly people with comorbidities.

Abiotrophia defectiva as a Rare Causative Agent of Periprosthetic Total Knee Arthroplasty Infections: A Case Report and Literature Review.

We present a case of Abiotrophia defectiva in a prosthetic knee infection following total knee replacement for the first time. A 69-year-old female was prediagnosed with prosthetic knee infection, and a two-stage revision arthroplasty was applied. A. defectiva was cultured by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from the synovial fluid aspirates. Penicillin G and gentamicin had been administered. One year postoperatively, a scintigraphy showed no recurrence. A. defectiva may be missed in culture negative patients with knee or hip arthroplasty. They should be carefully evaluated if they have undergone recent dental procedures.

Detection of Chlamydia pneumoniae and Helicobacter pylori in atherosclerotic plaques of carotid artery by polymerase chain reaction.

OBJECTIVES: A possible role of some microorganisms has been proposed in the pathogenesis of atherosclerosis, but it is still an unresolved issue. We investigated the presence of Chlamydia pneumoniae and Helicobacter pylori DNA in carotid artery atherosclerotic plaques by using PCR. METHODS: One hundred and four patients with atherosclerotic diseases were included. The study group consisted of 52 atherosclerotic plaque specimens obtained from the carotid arteries of patients who had carotid endarterectomy and the control group consisted of 52 specimens obtained from the macroscopically healthy regions of ascending aorta in patients who had undergone coronary artery bypass grafting. The presence of C. pneumoniae and H. pylori DNA in endarterectomy specimens were demonstrated by PCR. RESULTS: C. pneumoniae DNA was detected in 16 of 52 (30.8%) atherosclerotic plaques and 1 of 52 (1.9%) macroscopically healthy ascending aorta wall specimens (P < 0.001). H. pylori DNA was detected in 9 of 52 (17.3%) atherosclerotic plaques and none of the controls (P = 0.003). CONCLUSIONS: The higher incidence of C. pneumoniae and H. pylori DNA in atherosclerotic plaques suggests that these microorganisms may play a role in the pathogenesis of atherogenesis.

Peripheral mycotic aneurysms in infective endocarditis.

BACKGROUND AND AIM OF THE STUDY: Today, infective endocarditis (IE) remains a severe illness, with high mortality and morbidity. Mycotic aneurysms (MAs) are rare complications of IE. For most patients, surgical intervention represents the only hope for radical cure of extracranial MAs, and survival. METHODS: A total of 238 patients with IE was treated at the authors' center between January 1990 and December 2003. Among these patients, 10 underwent surgical intervention due to peripheral MAs. RESULTS: Concomitant surgery for intracardiac and extracardiac pathology was applied in three patients with native valve endocarditis to excise infected material. Aneurysmectomy and revascularization were performed in four patients with native endocarditis, and in three with prosthetic valve endocarditis (PVE). The intracardiac pathologies of these seven patients were treated with antimicrobial agents. Eight patients underwent surgery after completion of three weeks' antibiotic therapy. An autologous saphenous vein interposition was performed in eight patients, but in two cases, due to size discrepancy, a polytetraflouroethylene (PTFE) graft was chosen as the initial conduit to achieve arterial continuity. Saphenous vein graft rupture occurred in one patient; a PTFE graft was used to achieve second revascularization. Limb salvage was achieved in nine patients. Below-knee amputation was necessary in one patient; this was due to prior embolism of the distal arterial tree. Two patients died, one due to cerebral embolism and another to rupture of undiagnosed visceral MA. All other patients remain alive, without complications. CONCLUSION: Complete revascularization should be essential to treat peripheral MA in IE. Adequate resection, appropriate parenteral administration of antimicrobial agents and size discrepancy are far more important factors than the type of graft material in preventing suture-line infection and vessel or graft rupture.

A case of osteomyelitis due to Leuconostoc lactis.

A baby case of haematogenous rib osteomyelitis that was caused by Leuconostoc lactis was presented. The patient had high fever and an abscess formation on the right scapula. Diagnosis was made with the results of blood, bone and abscess cultures, pathological findings of the involved rib and direct bone graphies. The patient was treated succesfully with cefotaxime for 6 weeks.