这个study 全都是看染delta变异住院的病人。打过疫苗又感染的人年纪比较大（中间值56岁），没打疫苗的中间值是39.5岁； 打疫苗的人前5天viral load和没打的一样高，然后快速下降。打疫苗无症状的多，有症状也比较少。没打疫苗的有比较高的严重疾病的biomarker。
打疫苗的breakthrough case 和不打疫苗的比，97%有效不得（需要氧气的）重症或中症（肺炎）
The team found that individuals fully vaccinated with either Pfizer-BioNTech’s BNT162b2 vaccine or Moderna’s mRNA-1273 product were significantly less likely to develop moderate or severe outcomes following B.1.617.2 infection than unvaccinated individuals.
Vaccination was associated with fewer symptoms, lower peak biomarkers of systemic inflammation, and better clinical outcomes. It was also associated with a more rapid decline in viral RNA load and a robust serologic response.
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Multivariate logistic regression analysis revealed that vaccinated individuals were 97% less likely to develop severe COVID-19 that required oxygen supplementation or moderate disease (defined as development of pneumonia).