EBioMedicine | November 1, 2021

Monel B, Planas D, Grzelak L, Smith N, Robillard N, Staropoli I, Goncalves P, Porrot F, Guivel-Benhassine F, Guinet ND, Rodary J, Puech J, Euzen V, Bélec L, Orvoen G, Nunes L, Moulin V, Fourgeaud J, Wack M, Imbeaud S, Campagne P, Duffy D, Santo JPD, Bruel T, Péré H, Veyer D and Schwartz O

EBioMedicine. 2021;73:103637

https://doi.org/10.1016/j.ebiom.2021.103637

 Abstract

Background

The dynamics of SARS-CoV-2 alpha variant shedding and immune responses at the nasal mucosa remain poorly characterised.

Methods

We measured infectious viral release, antibodies and cytokines in 426 PCR+ nasopharyngeal swabs from individuals harboring non-alpha or alpha variants.

Findings

With both lineages, viral titers were variable, ranging from 0 to >10⁶ infectious units. Rapid antigenic diagnostic tests were positive in 94% of samples with infectious virus. 68 % of individuals carried infectious virus within two days after onset of symptoms. This proportion decreased overtime. Viable virus was detected up to 14 days. Samples containing anti-spike IgG or IgA did not generally harbor infectious virus. Ct values were slightly but not significantly lower with alpha. This variant was characterized by a fast decrease of infectivity overtime and a marked release of 13 cytokines (including IFN-b, IP-10 and IL-10).

Interpretation

The alpha variant displays modified viral decay and cytokine profiles at the nasopharyngeal mucosae during symptomatic infection.