RESUMEN
BackgroundAs of April 2021, three SARS-CoV-2 variants of concern (VOC: B.1.1.7, B.1.351 and P.1) have been detected in over 132 countries. Increased transmissibility of VOC has implications for public health measures and health system arrangements. This rapid scoping review aims to provide a synthesis of current evidence related to public health measures and health system arrangements associated with VOC. MethodsRapid scoping review. Seven databases were searched up to April 7, 2021 for terms related to VOC, transmission, public health and health systems. A grey literature search was conducted up to April 14, 2021. Title, abstracts and full text were screened independently by two reviewers. Data were double extracted using a standardized form. Studies were included if they reported on at least one of the VOC and public health or health system outcomes. ResultsOf the 2487 articles and 59 grey literature sources retrieved, 37 studies and 21 guidance documents were included. Included studies used a wide range of designs and methods. Most of the studies and guidance documents reported on B.1.1.7, and 18 studies and 4 reports provided data for consideration in relation to public health measures. Public health measures, including lockdowns, physical distancing, testing and contact tracing, were identified as critical adjuncts to a comprehensive vaccination campaign. No studies reported on handwashing or masking procedures related to VOC. For health system arrangements, 17 studies were identified. Some studies found an increase in hospitalization due to B.1.1.7 but no difference in length of stay or ICU admission. Six studies found an increased risk of death ranging from 15-67% with B.1.1.7 compared non-B.1.1.7, but three studies reported no change. One study reported on the effectiveness of personal protective equipment in reducing VOC transmission in the hospital. No studies reported on screening staff and visitors, adjusting service provisions, or adjusting patient accommodations and shared spaces, which is a significant gap in the literature. Guidance documents did not tend to cite any evidence and were thus assumed to be based on expert opinion. ConclusionWhile the findings should be interpreted with caution as most of the sources identified were preprints, findings suggest a combination of non-pharmaceutical interventions (e.g., masking, physical distancing, lockdowns, testing) should be employed alongside a vaccine strategy to improve population and health system outcomes. While the findings are mixed on the impact of VOC on health system arrangements, the evidence is trending towards increased hospitalization and death.
RESUMEN
Background: As of March 2021, three SARS-CoV-2 variants of concern (VOC) have been identified (B.1.1.7, B.1.351 and P.1) and been detected in over 111 countries. Despite their widespread circulation, little is known about their transmission characteristics. There is a need to understand current evidence on VOCs before practice and policy decisions can be made. This study aimed to map the evidence related to the transmission characteristics of three VOCs. Methods: A rapid scoping review approach was used. Seven databases were searched on February 21, 2021 for terms related to VOCs, transmission, public health and health systems. A grey literature search was conducted on February 26, 2021. Title/abstracts were screened independently by one reviewer, while full texts were screened in duplicate. Data were extracted using a standardized form which was co-developed with infectious disease experts. A second data extractor verified the results. Studies were included if they reported on at least one of the VOCs and transmissibility. Animal studies and modeling studies were excluded. The final report was reviewed by content experts. Results: Of the 1796 articles and 67 grey literature sources retrieved, 16 papers and 7 grey sources were included. Included studies used a wide range of designs and methods. The majority (n=20) reported on B.1.1.7. Risk of transmission, reported in 15 studies, was 45-71% higher for B.1.1.7 compared to non-VOCs, while R0 was 75-78% higher and the reported Rt ranged from 1.1-2.8. There was insufficient evidence on the transmission risk of B.1.35.1 and P.1. Twelve studies discussed the mechanism of transmission of VOCs. Evidence suggests an increase in viral load among VOCs based on cycle threshold values, and possible immune evasion due to increased ACE2 binding capacity of VOCs. However, findings should be interpreted with caution due to the variability in study designs and methods. Conclusion: VOCs appear to be more transmissible than non-VOCs, however the mechanism of transmission is unclear. With majority of studies focusing on the B.1.1.7 VOC, more research is needed to build upon these preliminary findings. It is recommended that decision-makers continue to monitor VOCs and emerging evidence on this topic to inform public health policy.