Convalescent individuals: decline of humoral responses against SARS-CoV-2 spike


In the absence of effective vaccines and with limited therapeutic options, convalescent plasma is being collected across the globe for potential transfusion to coronavirus disease 2019 ( COVID-19 ) patients.
The therapy has been deemed safe, and several clinical trials assessing its efficacy are ongoing.
While it remains to be formally proven, the presence of neutralizing antibodies is thought to play a positive role in the efficacy of this treatment.
Indeed, neutralizing titers of greater than or equal to 1:160 have been recommended in some convalescent plasma trials for inclusion.

Researchers have performed repeated analyses at 1-month intervals on 31 convalescent individuals to evaluate how the humoral responses against the severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ) spike glycoprotein, including neutralization, evolve over time.

It was observed that the levels of receptor-binding-domain ( RBD )-specific IgG and IgA slightly decreased between 6 and 10 weeks after the onset of symptoms but that RBD-specific IgM levels decreased much more abruptly.

Similarly, a significant decrease in the capacity of convalescent plasma to neutralize pseudoparticles bearing wild-type SARS-CoV-2 S or its D614G variant, was observed.

If neutralization activity proves to be an important factor in the clinical efficacy of convalescent plasma transfer, plasma from convalescent donors should be recovered rapidly after resolution of symptoms.

While waiting for an efficient vaccine to protect against SARS-CoV-2 infection, alternative approaches to treat or prevent acute COVID-19 are urgently needed.
Transfusion of convalescent plasma to treat COVID-19 patients is currently being explored; neutralizing activity in convalescent plasma is thought to play a central role in the efficacy of this treatment.
The new study has shown that plasma neutralization activity decreases a few weeks after the onset of the symptoms. ( Xagena )

Beaudoin-Bussières G et al, mBio 2020;11(5):e02590-20. doi: 10.1128/mBio.02590-20.

XagenaMedicine_2020



Indietro

Altri articoli

Data from the five-year analysis featuring extended follow-up from the phase III COMBI-AD study have confirmed that 12 months of...


There has been an only indirect comparison between Pembrolizumab ( Keytruda ) and Pembrolizumab plus chemotherapy in patients with non-small...


The aim of neo-adjuvant therapy in locally advanced or oligometastatic melanoma is to facilitate radical resection, improve outcomes and undertake...


The ALEX study has demonstrated significantly improved progression-free survival ( PFS ) with Alectinib ( Alecensa ) versus Crizotinib (...


The mRNA-1273 vaccine for SARS-CoV-2 is tolerable and immunogenic in older adults. Data on prolonged immunogenicity and effectiveness in preventing severe...


The European Commission ( EC ) has granted conditional marketing authorization to Ayvakyt ( Avapritinib ) as a monotherapy for...


The U.S. Food and Drug Administration ( FDA ) has approved Gallium 68 PSMA-11 ( Ga 68 PSMA-11 ), the...


The FDA ( U.S. Food and Drug Administration ) has approved Ayvakit ( Avapritinib ) for the treatment of adults...


The European Commission ( EC ) has granted marketing authorisation for the expanded use of Erleada ( Apalutamide ) to...