Motivated by historical and present clinical observations, we discuss the possible unfavorable evolution of the immunity (similar to documented antibody-dependent enhancement scenarios) after a first infection with COVID-19. More precisely we ask the question of how the epidemic outcomes are affected if the initial infection does not provide immunity but rather sensitization to future challenges. We first provide background comparison with the 2003 SARS epidemic. Then we use a compartmental epidemic model structured by immunity level that we fit to available data; using several scenarios of the fragilization dynamics, we derive quantitative insights into the additional expected numbers of severe cases and deaths.

根据历史和当前的临床观察结果，我们讨论首次感染COVID-19后免疫力可能发生的不利变化（类似于已证明的抗体依赖性增强方案）。更确切地说，我们问一个问题：如果最初的感染不能提供免疫力，而是对未来挑战敏感，那么流行病的后果将受到怎样的影响。我们首先提供与2003年SARS流行的背景比较。然后，我们使用由免疫力水平构成的隔离流行模型，以适应可用数据。使用脆弱性动态化的几种方案，我们获得了对严重病例和死亡人数的额外预期数量的定量见解。