Virological and Serological Characterization of SARS-CoV-2 Infections Diagnosed After mRNA BNT162b2 Vaccination

Abstract Coronavirus disease 2019 (COVID-19) vaccines are proving to be very effective in preventing severe illness; however, although rare, post-vaccine infections have been reported. The present study describes 94 infections (47.9% symptomatic, 52.1% asymptomatic), occurred in Lazio Region (Central Italy) in the first trimester 2021, after first or second dose of mRNA BNT162b2 vaccine. Median viral load at diagnosis was independent from number and time of vaccine dose administration, despite the higher proportion of samples with low viral load observed in fully vaccinated individuals. More importantly, infectious virus was cultured from NPS collected from both asymptomatic and symptomatic vaccinated individuals, suggesting that, at least in principle, they can transmit the infection to susceptible people. The majority of the post-vaccine infections here reported, showed pauci/asymptomatic clinical course, confirming the impact of vaccination on COVID-19 disease. Most cases (78%) showed infection in presence of neutralizing antibodies at the time of infection diagnosis, presumably attributable to vaccination, due to the concomitant absence of anti-N IgG in most cases. The proportion of post-vaccine infections attributed either to Alpha and Gamma VOCs was similar to the proportion observed in the contemporary unvaccinated population in Lazio region. In addition, mutational analysis did not suggest enrichment of a defined set of Spike protein substitutions depending on the vaccination status. Characterization of host and virus factors associated with vaccine breakthrough, coupled with intensive and continuous monitoring of involved viral strains, is crucial to adopt informed vaccination strategies..

Medienart:

Preprint

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

bioRxiv.org - (2021) vom: 24. Sept. Zur Gesamtaufnahme - year:2021

Sprache:

Englisch

Beteiligte Personen:

Colavita, Francesca [VerfasserIn]
Meschi, Silvia [VerfasserIn]
Maria Gruber, Cesare Ernesto [VerfasserIn]
Rueca, Martina [VerfasserIn]
Vairo, Francesco [VerfasserIn]
Matusali, Giulia [VerfasserIn]
Lapa, Daniele [VerfasserIn]
Giombini, Emanuela [VerfasserIn]
Carli, Gabriella De [VerfasserIn]
Spaziante, Martina [VerfasserIn]
Messina, Francesco [VerfasserIn]
Bonfiglio, Giulia [VerfasserIn]
Carletti, Fabrizio [VerfasserIn]
Lalle, Eleonora [VerfasserIn]
Fabeni, Lavinia [VerfasserIn]
Berno, Giulia [VerfasserIn]
Puro, Vincenzo [VerfasserIn]
Caro, Antonino Di [VerfasserIn]
Bartolini, Barbara [VerfasserIn]
Ippolito, Giuseppe [VerfasserIn]
Capobianchi, Maria Rosaria [VerfasserIn]
Castilletti, Concetta [VerfasserIn]

Links:

Volltext [kostenfrei]

doi:

10.1101/2021.09.21.21263882

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

XBI03263465X