key: cord-0816430-v753vxaq
authors: Edelstein, Shimon; Tannous, Shebly; Jacobs, Mevasseret T.; Ben-Amram, Hila; Zarka, Salman
title: BNT 13b2 Pfizer vaccine protects against SARS-CoV-2 respiratory mucosal colonization even after prolonged exposure to positive family members
date: 2021-03-31
journal: J Hosp Infect
DOI: 10.1016/j.jhin.2021.03.023
sha: 66969b68431a872e6300220541c80edbb4dba8aa
doc_id: 816430
cord_uid: v753vxaq

nan

Coronavirus disease 2019 , is a new disease caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the State of Israel, with a population of roughly 9 million, approximately 700,000 people have recovered from COVID-19, and to date 56% of the total population have been vaccinated (BNT 13b2 Pfizer). Ziv Medical Center (ZMC) is a periphery hospital in Northern Israel, with about 1,800 employees. In the past year, 12% of hospital employees became ill with COVID-19, and by the end of January 2021, 91% of the non-infected employees had been vaccinated. Despite the herd-immunity of the medical staff, most of them returned home, to locations where the epidemic was raging, in communities in which more than 7% of members were verified COVID-19-positive. Vaccinated workers did not have to quarantine even if a verified patient resided in their home, and they were allowed to continue working regularly at the hospital, unless they developed suspicious clinical symptoms for COVID-19. However, prolonged exposure to a positive family member living in the same house may be a challenge to the immune system, unlike exposure to a positive patient for a short period.

The main glycoproteins in the gel layer of the respiratory mucosa are mucins, a component glycosylated proteins designed to block the penetration of pathogens, as well as defensin and other components, together with an adaptive component of the immune system: immunoglobulin A (IgA) [1, 2] . IgA serum level is 2-3 mg/ml, a quarter of the level of immunoglobulin G (IgG). The role of IgA stems from its various locations in the body and from its role in binding pathogens planning invasion [3] . Unlike other antibodies, IgA does not activate the complement system. Its primary action in the mucosa is to bind to the virus and prevent its binding to high affinity receptors [4] . The Pfizer BNT 13b2 vaccine produces IgG antibodies against the spike protein [5] . These IgG antibodies are not found in mucous membranes and These findings are encouraging, especially in light of the way mRNA triggers the immune system. BNT 13b2 Pfizer is a new vaccine whose properties are still being studied. Because its mechanism of action induces the production IgG antibodies only, in contrast to IgA antibodies, which are formed naturally in infected persons, the concern is that the virus may bind to the mucous membranes and cultivate in its superficial epithelial cells, making the vaccinated person a carrier. Our findings indicate that the BNT 13b2 Pfizer vaccine is effective against mucosal colonization of SARS-CoV-2 even during prolonged exposure (a total of 120 days of exposure for fourteen employees). None of the employees developed COVID-19 symptoms or signs. This is the first report describing the effectiveness of the vaccine in preventing the virus from adhering to the mucosa of vaccinated persons, precluding the possibility of carrying the virus.

J o u r n a l P r e -p r o o f

Barrier function of the nasal mucosa in health and type-2 biased airway diseases. A llergy

The central role of the nasal microenvironment in the transmission, modulation, and clinical progression of SA RS-CoV -2 infection

The function of immunoglobulin A in immunity

Biological activities of IgA In M ucosal Immunology

Safety and Immunogenicity of Two RNA -Based Covid-19 V accine Candidates