key: cord-0736671-vhk2jyyz
authors: Baos, Elvira; Delgado-Iribarren, Alberto; O´Connor, Silvia; Bardón, Ignacio; Alvaréz, Mar; Rodríguez-Avial, Iciar; Culebras, Esther
title: Negative effect of the second dose of the BNT162b2 vaccine in a significant percentage of individuals with previous COVID infection
date: 2021-11-05
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2021.11.002
sha: 6f65124fcd7613abc8a3726446b5980230753d0c
doc_id: 736671
cord_uid: vhk2jyyz

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In order to advance in pandemic control, some governments have decided to delay 40 administration of the second vaccine dose. They assume that the first dose would be 41 enough to protect population for a longer period than pharmaceutical company 42 recommended (Prendecki et al., 2021) . Some previous works support this affirmation 43 (Gobbi et al., 2021; Saadat et al., 2021) (Saadat et al., 2021; Prendecki et al., 2021) .

In January 2021, the Pfizer -BioNTech BNT162b2 began to be administered in health 48 care workers in Spain. The main objective of this study was to analyze the response to 49 the first and second doses of this vaccine in health care workers from Hospital Clinico milliliter. The positive threshold were 50 AU/mL as manufacturer´s recommendation.

According to EP34 Guide of CLSI (Budd, 2018) the ranges of results values that can be 59 reported are 21.0-40,000 AU/mL (analytical measurement range) and 40,000-80,000 60 AU/mL (extended measurement range). In order to simplify calculations, any value > 61 80,000 AU/mL was considered equal to 81,000 AU/mL. Our data, as other previously studies (Krammer et al., 2021) , indicates the differences in 

This work did not receive any specific funding. 

Establishing and verifying an Extended Measuring Interval Through 131

Humoral and cell-mediated response elicited by SARS-CoV-2 mRNA vaccine 136

BNT162b2 in healthcare workers: a longitudinal observational study

Antibody response 139 to the BNT162b2 mRNA COVID-19 vaccine in subjects with prior SARS-CoV-140 2 infection

CoV-2 mRNA Vaccine

mRNA vaccination 145 in people over 80 years of age induces strong humoral immune responses against 146

SARS-CoV-2 with cross neutralization of P.1 Brazilian variant

Effect of 149 previous SARS-CoV-2 infection on humoral and T-cell responses to single

BNT162b2 vaccine

Binding and neutralization antibody titers after a single vaccine dose in health 153 care workers previously infected with sars-CoV-2