https://www.selleckchem.com/products/Mubritinib-TAK-165.html Interestingly, one mutation in the receptor binding domain of the S protein results in the change of an asparagine to tyrosine residue at position 501 (N501Y). This mutation is also present in the newly emerging SARS-CoV-2 variant viruses reported in the U.K. (20B/501Y.V1, B1.1.7 lineage) that is epidemiologically associated with high human to human transmission. We show that human convalescent and post vaccination sera can neutralize the newly emerging N501Y virus variant with similar efficiency as that of the reference USA-WA1/2020 virus, suggesting that current SARS-CoV-2 vaccines will protect against the 20B/501Y.V1 strain. Large-scale deployment of safe and durably effective vaccines can halt the COVID-19 pandemic. However, the high vaccine efficacy reported by ongoing phase 3 placebo-controlled clinical trials is based on a median follow-up time of only about two months and thus does not pertain to long-term efficacy. To evaluate the duration of protection while allowing trial participants timely access to efficacious vaccine, investigators can sequentially cross placebo recipients to the vaccine arm according to priority groups. Here, we show how to estimate potentially time-varying placebo-controlled vaccine efficacy in this type of staggered vaccination of placebo recipients. In addition, we compare the performance of blinded and unblinded crossover designs in estimating long-term vaccine efficacy. We show how to estimate potentially waning long-term efficacy of COVID-19 vaccines in randomized, placebo-controlled clinical trials with staggered enrollment of participants and sequential crossover of placebo recipients. We show how to estimate potentially waning long-term efficacy of COVID-19 vaccines in randomized, placebo-controlled clinical trials with staggered enrollment of participants and sequential crossover of placebo recipients. To detect unilateral vocal fold paralysis (UVFP) from voice re