A second dose deferred strategy has been proposed to increase initial population immunity as an alternative to the default two dose vaccine regimen with spacing of 21 or 28 days between vaccine doses for the mRNA vaccines from Pfizer and Moderna. This increased initial population immunity is only of value if one dose immunity does not decay so fast as to nullify the benefit. Because decay rates of one dose and two dose efficacy are currently unknown, a model to project population immunity between the two strategies was created. By evaluating the decay rate of one dose efficacy, two dose efficacy, and time until the second dose is given, the model shows that if there is an increased decay rate of one dose efficacy relative to two dose decay rates, it is highly unlikely to nullify the benefit of increased population immunity seen in a second dose deferral strategy. Rather, all reasonable scenarios strongly favour a second dose deferral strategy with much higher projected population immunity in comparison to the default regimen.

中文翻译：

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用建议的第二剂量递延策略模拟人口免疫力的衰减

已经提出了第二种推迟剂量的策略，以增加初始种群的免疫力，作为默认的两剂疫苗方案的替代方案，对于来自辉瑞和Moderna的mRNA疫苗，疫苗剂量之间间隔21或28天。仅当一个剂量的免疫不会很快衰减而使获益无效时，这种增加的初始种群免疫才有价值。由于目前尚不知道一剂和两剂疗效的衰减率，因此创建了一个模型来预测两种策略之间的人群免疫力。通过评估一剂药效，两剂药效和直到第二剂给药的时间的衰减率，该模型表明，如果一剂药效的衰减率相对于两种剂药衰减率增加，在第二剂延期治疗策略中，提高人群免疫力所带来的好处极不可能消除。而是，所有合理的方案都强烈建议采用第二种剂量延期策略，与默认方案相比，该策略具有更高的预计人群免疫力。