Can Individuals with Suboptimal Antibody Responses to Conventional Antiviral Vaccines Acquire Adequate Antibodies from SARS-CoV-2 mRNA Vaccination?

In Japan, healthcare workers (HCWs) are vaccinated against measles, rubella, chickenpox, mumps, and hepatitis B to prevent nosocomial infection; however, some do not produce sufficient antibodies ("suboptimal responders"). This study compared immune responses to a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 mRNA) vaccine among HCWs with normal and suboptimal responses to conventional vaccines. In this prospective cohort study, 50 HCWs received two doses of BNT162b2 mRNA vaccine 3 weeks apart. SARS-CoV-2 anti-spike antibodies were measured 11 times, starting before the first vaccination and ending 5 months after the second vaccination. Antibody titers of four suboptimal and 46 normal responders were compared. SARS-CoV-2 neutralizing antibody activity was measured twice in suboptimal responders, 1 week/1 month and 5 months after the second vaccination. The SARS-CoV-2 anti-spike antibody was detectable in the samples from suboptimal and normal responders at each timepoint after vaccination. Suboptimal responders exhibited SARS-CoV-2 neutralizing antibody activity 1 week/1 month as well as 5 months after the second vaccination; however, activity was slightly reduced at 5 months. Our findings show that suboptimal responders do acquire adequate SARS-CoV-2 anti-spike and SARS-CoV-2 neutralizing antibodies from vaccination to prevent SARS-CoV-2. SARS-CoV-2 mRNA vaccines should thus be recommended for both normal and suboptimal responders to conventional vaccines.

Establishing an internal quality control method for the stable extraction of nucleic acids of severe acute respiratory syndrome coronavirus 2 and RT-PCR-based detection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus disease 2019 (COVID-19), is detected using real-time RT-PCR. However, there are limitations pertaining to quality control, particularly with respect to establishing quality control measures for extraction of viral nucleic acids. Here, we investigated the quality control measures for the various processes using an extrinsic quality control substance and quality control charts. METHODS: An extrinsic quality control substance was added to the sample, and then, real-time RT-PCR was performed. Samples with negative test results and the corresponding data were analyzed; a quality control chart was created and examined. RESULTS: Data analysis and the quality control charts indicated that SARS-CoV-2 could be reliably detected using real-time RT-PCR, even when different nucleic acid extraction methods were used or when different technicians were employed. CONCLUSION: With the use of quality control substances, it is possible to achieve quality control throughout the process-from nucleic acid extraction to nucleic acid detection-even upon using varying extraction methods. Further, generating quality control charts would guarantee the stable detection of SARS-CoV-2.

Diagnostic accuracy for drug detection using liquid chromatography/mass spectroscopy in overdose patients.

AIM: Information about the causative drugs is essential for appropriate treatment for drug overdose, but patients sometimes cannot provide information about overdosed drugs owing to disturbed consciousness or an unwillingness to cooperate with treatment. The purpose of this study was to decide whether liquid chromatography/mass spectroscopy (LC/MS) is useful as a detection method for overdosed drugs. METHODS: Overdose patients (n = 279) treated in our facility were retrospectively studied. Specimens from gastric lavage, blood serum, and urine were tested using LC/MS. The matching rates between drugs overdosed and those detected by LC/MS were evaluated; LC/MS and Triage DOAR were also compared. Data are shown as means. RESULTS: Patients overdosed on 3.2 kinds of drugs and were transferred to our hospital 4.6 h after. Overall 3.5 kinds of drugs were detected by LC/MS, and 2.4, 1.9, and 2.2 kinds were from the stomach, blood, and urine, respectively. Matching rate among the ingested drugs (kinds of drugs matched/ones ingested) was the highest in the gastric samples (0.56), and the lowest in the urine samples (0.46) (P < 0.01). In addition, the matching rates among the detected drugs (kinds of drugs matched/ones detected) were as high as 0.74 and 0.78 in the gastric and blood samples, respectively. Comparing the sensitivity and specificity of detection of benzodiazepines and tricyclic antidepressants between LC/MS and Triage DOAR, we found that these two methods were comparable. CONCLUSION: Liquid chromatography/mass spectroscopy was proven to be an effective method to detect overdosed drugs, especially when there was not enough information about the drugs ingested.

[Improvement of a multi-target screening analysis for drugs using a QTRAP liquid chromatography/tandem mass spectrometry system].

We have investigated the usefulness of an improved multi-target screening method based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis on a hybrid triple-quadrupole linear ion trap mass spectrometer for detecting major drugs in toxicological analysis. Fifteen drugs, most frequently detected in intoxicated patients treated at the emergency medicine section in our institute, were mixed together in serum or urine at concentration of 100 ng/ml each, and then extracted by liquid-liquid extraction using 1-chlorobutane, followed by an analysis using LC/MS/MS. By setting the collision energy at the multiple reaction monitoring mode and declustering potential at the enhanced product ion scan mode individually for each drug, clinically satisfactory sensitivity was attained for the detection of drugs in extracted samples. The results of the present study on several serum/urine samples of intoxicated patients indicated that this method is superior to other screening methods in reliability. Taken together, our improved LC/MS/MS analysis is useful for detecting major drugs causing intoxication in the field of emergency medicine.