Incursion of SARS-CoV-2 BA.2.86.1 variant into Israel: National-scale wastewater surveillance using a novel quantitative real-time PCR assay

The emergence of the SARS-CoV-2 variant BA.2.86.1 raised a considerable concern, due to the large number of potentially virulent mutations. In this study, we developed a novel assay that specifically detects variant BA.2.86.1, and used it to screen environmental samples from wastewater treatment sites across Israel. By using a multiplex assay that included a general SARS-CoV-2 reaction, together with the BA.2.86.1-specific reaction and a control reaction, we quantified the absolute number of viral copies in each sample and its relative abundance, compared with the total copy number of circulating SARS-CoV-2. Evaluation of the new reactions showed that they are both sensitive and specific, detecting down to four copies per reaction, and maintain specificity in the presence of Omicron variants BA.1, 2 and 4 RNA. Examination of 279 samples from 30 wastewater collection sites during August-September 2023 showed that 35 samples (12.5 %) were positive, from 18 sites. Quantitative analysis of the samples showed that the relative abundance of variant BA.2.86.1 with respect to the total viral load of SARS-CoV-2 was very low and consisted between 0.01 % and 0.6 % of the total SARS-CoV-2 circulation. This study demonstrates the importance of combining wastewater surveillance with the development of specialized diagnostic assays, when clinical testing is insufficient. This approach may be useful for timely response by public health authorities in future outbreaks.

Measles outbreak associated with a preschool setting among partially vaccinated children in the Tel Aviv District, Israel, October 2023

In October 2023, the Tel Aviv District was notified of ten cases of measles. The outbreak initiated in a preschool with high vaccination coverage with one dose of MMR vaccine. Serological testing was available for eight patients (six children and two adults). Among the six children vaccinated with one dose of MMR vaccine, primary vaccine failure was demonstrated. Among the adults, secondary vaccine failure was confirmed. The outbreak was successfully contained due to a combination of factors, notably its occurrence within a population characterized by high vaccination coverage in Tel Aviv, during a period of restricted public interactions due to the prevailing state of war in the country. Despite challenging wartime conditions, effective prophylactic measures were promptly executed, encompassing a 2-dose MMR vaccination schedule for close contacts and the broader community of children in the TA district, successfully curbing the outbreak and preventing widespread infections.

Reporting of Allergic Reactions During Pfizer-BioNTech BNTT162B2 Vaccination in Israel

Background

In December 2020, the Israeli Ministry of Health launched a national vaccination campaign against SARS-CoV-2. Concomitant sporadic reports on anaphylactic responses in other countries raised safety concerns at the outset of this operation.

Objective

To characterize reports on allergic reactions to coronavirus disease 2019 vaccines.

Methods

Allergy events were reported by health care professionals throughout the country to Israeli Ministry of Health Division of Epidemiology via a Web-based computerized national vaccine registry. The study period was from December 19, 2020 to September 13, 2021, during which 14,475,979 injections were administered.

Results

Allergic reactions were reported in 463 subjects, 99.3% of whom received Pfizer-BioNTech BNTT162B2. The reporting rate was 106 per million in December 2020. From January to May 2021, a reduction was observed to 66, 18, 14, eight, and zero per million, and reporting remained low until September. Mean age of subjects was 48.9 ± 16.7 years (range, 15-96 years) with a female preponderance of 78%. Epinephrine was administered in 34 subjects. Validated immediate allergy was observed in only 37 cases (8%), suggesting 2.5 to 3.3 bona fide reactions per million. In subjects with reactions classified as severe (n = 46), plausible allergy was identified in 36% to 41% of cases. A history of allergy was associated with high false reporting of immediate reactions (83%). Allergic events after the first dose did not compromise adherence to subsequent doses.

Conclusions

Excessive reporting of allergy declined over time and did not affect adherence to vaccination. The existence of previous allergy may affect reporting profiles, but not the occurrence of vaccine allergy.