MGH FLARE - May 5 - New Data on Protective Immunity After COVID-19
►https://mailchi.mp/5516584b186d/tz4idnzryr-4417417?e=06f3eb75c2
(Analyse la publication suivante:
Ni, L., Ye, F., Cheng, M.-L., Feng, Y., Deng, Y.-Q., Zhao, H., Wei, P., Ge, J., Gou, M., Li, X., Sun, L., Cao, T., Wang, P., Zhou, C., Zhang, R., Liang, P., Guo, H., Wang, X., Qin, C.- F., Chen, F., Dong, C., Detection of SARS-CoV-2-specific humoral and cellular immunity in COVID-19 convalescent individuals, Immunity (2020)
▻https://www.cell.com/immunity/pdf/S1074-7613(20)30181-3.pdf)
The study by Ni et al. provides encouraging, but not definitive, data that humans will develop protective immunity after COVID-19. However, similar to all of the prior COVID-19 immunology studies, the paper by Ni et al. had a very small cohort of patients, so larger studies across a variety of age ranges and severity of illness are needed. Furthermore, this study does not have data about changes in humoral and cellular immunity over time in the same patients. Lastly, studies will be needed to define the “immune correlates” of protective immunity. That is, what level of antibody or memory T cell pool size is needed to confer host protection? As noted in a prior FLARE [►https://seenthis.net/messages/847479], in both SARS and MERS, individuals who suffered more severe primary infection seemed to exhibit more long-lasting, antigen-specific immune memory (Memish et al., 2020; Tang et al., 2011; Zhao et al., 2017).
While this study provides the most comprehensive evidence that individuals who recover from COVID-19 will acquire protective immunity, the duration of such protection remains unknown. The conclusion of our April 24th FLARE [►https://seenthis.net/messages/847479] holds: if SARS-CoV-2 establishes itself in the human population and protective immunity wanes over time, the development of an effective vaccine will be essential to protect both naïve individuals as well as survivors with waning immunity.
We also await a comprehensive serological assessment of patients with severe COVID-19. Could disease severity correlate with inadequate early humoral response? Or does increased disease severity actually lead to a more robust antibody response, perhaps increasing duration of immunity? As antibody tests become more widely used, especially given FDA’s emergency use authorization of an antibody test by Roche on May 5th, 2020, we anticipate answers to these important questions in the next few weeks.