Efficacy of the mRNA-1273 SARS-CoV-2 vaccine at completion of blinded phase

BACKGROUND At interim analysis in a phase 3, observer-blinded, placebo-controlled clinical trial, the mRNA-1273 vaccine showed 94.1% efficacy in preventing coronavirus disease 2019 (Covid-19). After emergency use of the vaccine was authorized, the protocol was amended to include an open-label phase. Final analyses of efficacy and safety data from the blinded phase of the trial are reported. METHODS We enrolled volunteers who were at high risk for Covid-19 or its complications; participants were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 μg) or placebo, 28 days apart, at 99 centers across the United States. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data cutoff date was March 26, 2021. RESULTS The trial enrolled 30,415 participants; 15,209 were assigned to receive the mRNA-1273 vaccine, and 15,206 to receive placebo. More than 96% of participants received both injections, 2.3% had evidence of SARS-CoV-2 infection at baseline, and the median follow-up was 5.3 months in the blinded phase. Vaccine efficacy in preventing Covid-19 illness was 93.2% (95% confidence interval [CI], 91.0 to 94.8), with 55 confirmed cases in the mRNA-1273 group (9.6 per 1000 person-years; 95% CI, 7.2 to 12.5) and 744 in the placebo group (136.6 per 1000 person-years; 95% CI, 127.0 to 146.8). The efficacy in preventing severe disease was 98.2% (95% CI, 92.8 to 99.6), with 2 cases in the mRNA-1273 group and 106 in the placebo group, and the efficacy in preventing asymptomatic infection starting 14 days after the second injection was 63.0% (95% CI, 56.6 to 68.5), with 214 cases in the mRNA-1273 group and 498 in the placebo group. Vaccine efficacy was consistent across ethnic and racial groups, age groups, and participants with coexisting conditions. No safety concerns were identified. CONCLUSIONS The mRNA-1273 vaccine continued to be efficacious in preventing Covid-19 illness and severe disease at more than 5 months, with an acceptable safety profile, and protection against asymptomatic infection was observed

Using Real-Time Polymerase Chain Reaction to Determine Spatial Distribution of Multiple Species of Shellfish

The success of both wild and cultured shellfish populations is dependent upon recruitment of planktonic larvae. Due to issues of cost, time, expertise and inaccuracy associated with bivalve identification using microscopy, real-time polymerase chain reaction is being employed to identify and quantify larvae using DNA technology. We are quantifying species-specific abundance and distribution of four commercially important species using novel approaches. Environmental samples were collected via two rounds of in-situ pumping at four locations in intertidal waters in Washington State. Pumping was performed at two depths: near the water surface and above the sea floor and at two times: before sunrise and sunset, in order to determine the spatial and temporal distribution of bivalve larvae. Genetic assays for Pacific geoduck clam (Panopea generosa) Olympia oyster (Ostrea lurida), Pacific oyster (Crassostrea gigas) and Manila clam (Venerupis philippinarum) have been designed. The collected field samples are currently undergoing qPCR quantification using these assays. Results will be analyzed to determine cross-species patterns or species-specific behavior in larval distribution throughout Washington State. This information will provide a comprehensive snapshot of the larvae of multiple shellfish species in Washington. Additionally, this information may further be utilized by hatcheries by providing the best times and locations for hatcheries to plant cultured seeds and substrate and by researchers studying the effects of localized ocean acidification

The winner goes to: A comparison of techniques to identify and quantify bivalve larvae in environmental samples in Washington State

Reliable detection and quantification of bivalve larvae during critical life stages is crucial in forecasting population abundance, recruitment, behavior, and dispersal. Therefore, it is scientifically and commercially valuable to develop an efficient method to quantify larval presence and abundance. Commonly used methods for approximating larval abundance involve distinguishing morphological differences between bivalve species in environmental plankton samples (EPS) by microscopy. This method is problematic during earlier stages of larval development and rely on high amounts of expertise in bivalve larvae identification. Most recently, approaches using TaqMan probe-based multiplex real-time polymerase chain reaction (RT-PCR) to quantify copies of DNA in comparison to a standard curve of known larvae has been successfully applied to cultivated larval samples. However, few studies have performed comprehensive comparisons of these methods using EPS. In the present study, assays to determine absolute quantification using a standard curve of the Pacific geoduck clam (Panopea generosa), Pacific oyster Crassostrea gigas), Olympia oyster (Ostrea lurida), and Manila clam (Venerupus phillipinarum) were developed and compared to microscopy techniques using morphological traits of the same species in two pulses of EPS at four relevant sites throughout Washington State. Preliminary results indicate the resourcefulness of using TaqMan chemistry to detect larval presence in known amounts of cultured larvae spiked in mock-up plankton samples as well as the presence of bivalve larvae in collected EPS. We predict that high-throughput RT-PCR will prove to be less time consuming and more reliable than microscopy in quantifying species specific abundances in EPS