key: cord-1008366-3d4dx7tu
authors: Porto, Miriam Hernández; Castro, Beatriz; Diaz, Zaida; Pedroso, Yanet; Ramos, María José; Lecuona, María
title: SARS-CoV-2 infection in properly vaccinated healthcare workers
date: 2021-06-09
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2021.06.010
sha: ca89548f6bd782b47fd7925009f91bc014b98f1e
doc_id: 1008366
cord_uid: 3d4dx7tu

Background BNT162b2 mRNA Covid-19 vaccine has shown an optimal protection for population. However the development of SARS-CoV-2 infection has been reported in persons, who have received one or both doses of vaccine. The Hospital Universitario de Canarias began to vaccinate to healthcare workers on Febraury, 2021. We have detected several asymptomatic cases of SARS-CoV2 infections in healthcare workers. Methods We performed PCR on health staff at our Centre after the two doses of vaccination, which were realized by screening in close contact with positive cases, new addition to the hospital or a requirement before traveling to another region in the country. In positive cases we determined the quantitative IgG (post-vaccine Spike1-RBD and nucleocapside) and IgM (Spike1-RBD). Results We detected five cases of SARS-CoV-2 infection in properly vaccinated healthcare workers after 15 days of the second dose vaccine. All cases had high Cts values and were asymptomatics. The Post-vaccine IgG level was between 778.9-4,420.7 BAU/ml. Conclusions This communication reflects how vaccination protected healthcare workers from disease; however, it remains to be analyzed the transmissibility of virus after vaccination. We consider the importance of preserving, at the moment, prevention measures against SARS-CoV-2 virus in the hospital environment, mainly by vaccinated healthcare staff.

BNT162b2 mRNA Covid-19 vaccine has shown an optimal protection for population (Polak et al., 2020) ; this vaccine generate the codification of Spike protein with high levels of inmunity.

In the study of Jingyou Yu et al. 2020 carried out on monkeys, they reported infections after exposure to the virus in properly vaccinated animals, but in turn showed much lower viral loads than those of the unvaccinated control group and suggested that neutralizing antibodies levels of post-vaccine serum correlated with SARS-CoV-2 protection.

Currently, after infection with this virus, the titers of neutralizing antibodies produced are considered to be correlated with the protection against SARS-CoV-2 (Suthar et al., 2020 , Manisty et al., 2021 although the production of these antibodies is not a prerequisite for infection resolution. (Prévost et al., 2020 , Reynolds et al., 2020 On the other hand, assays that detect RBD (receptor-binding domain) IgG are highly specific and sensitive, and the information in their titles can be used as substitutes for neutralizing activity against SARS-CoV-2 (Suthar et al., 2020) . It should also be noted that WHO (World Health Organization 2020) has not yet established the levels of antibodies needed to determine vaccine efficacy or durability.

BNT162b2 mRNA Covid-19 vaccine in; close contact with positive cases, new addition of healthcare worker to the hospital or a requirement before traveling to another region in the country.

The microbiology diagnostic was established by real time PCR (Allplex SARS-CoV-2/FluA/FluB/RSV Assay, Seegene) in nasopharyngeal swabs taken from both nostrils. This assay detect and differentiate three different target genes of COVID-19 (S gene, RdRP gene and N gene). 

European Centre for Disease Prevention and Control. Risk of SARS-CoV-2 transmission from newly-infected individuals with documented previous infection or vaccination

What defines an efficacious COVID-19 vaccine? A review of the challenges assessing the clinical efficacy of vaccines against SARS-CoV-2

Time series analysis and mechanistic modelling of heterogeneity and sero-reversion in antibody responses to mild SARS-CoV-2 infection

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine

Cross-Sectional Evaluation of Humoral Responses against SARS-CoV-2 Spike

Rapid Generation of Neutralizing Antibody Responses in COVID-19 Patients

Healthcare workers with mild / asymptomatic SARS-CoV-2 infection show T cell responses and neutralising antibodies after the first wave. medRxiv

Establishment of the WHO International Standard and Reference Panel for anti-SARS-CoV-2 antibody