key: cord-0746320-96rl94rc
authors: Pandolfi, Sergio; Chirumbolo, Salvatore
title: On reaching herd immunity during the COVID‐19 pandemic and further issues
date: 2021-09-12
journal: J Med Virol
DOI: 10.1002/jmv.27322
sha: 101893750256408bfd9c579688b0487a5d34aa6b
doc_id: 746320
cord_uid: 96rl94rc

nan

To the Editor,

The global and pervasive awareness that vaccination against COVID-19 is dramatically urgent has even enrolled, in a quiet silent way, healed, unaware and swab-negative people, who were previously immunized from the direct contact with SARS-CoV2. 1 Obviously, the burdensome effort to check if subjects were endowed with serum anti-RBD IgGs, or not (naïve people), was completely overshadowed by the pandemic emergency. Despite this attitude being anything but scientific, the recent report by Callegaro et al., in this journal, showed that median titers for specific antibodies in people previously infected with SARS-CoV2 or having undergone COVID-19 increased once following even a single dose of vaccine. 1 illness, resulted in a marked production of antibodies, decisively higher than in SARS-CoV2 naïve people. 1 In this context, one should wonder if as higher is the serum anti-RBD IgG level, as safer is the vaccine coverage against the next forthcoming SARS-CoV2 infection, but no reliable data exist about this. Actually, politics is holding the vaccination campaign indiscriminately upon people despite their IgG serology, never mind if naïve (never been infected) or immunized.

The question of how much SARS-CoV2 immunized people may account for reaching herd immunity should be a leading issue for expanding the debate and address politely the many raising outcries against vaccination.

Interestingly, people being infected with SARS-CoV2, either in an asymptomatic or symptomatic way and lately developing a serum immunity, have a different B-cell and T-ell memory with respect to vaccinated individuals, due to the initial SIgA-B cell mucosal response driving a sustained IgG-B cell memory, 8 which is the next horizon the recent straightforward and innovative RNA-based vaccines would

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Antibody responses to SARS-CoV-2 vaccines in 45,965 adults from the general population of the United Kingdom

Antibody responses after a single dose of ChAdOx1 nCoV-19 vaccine in healthcare workers previously infected with SARS-CoV-2

Antibody responses to the BNT162b2 mRNA vaccine in individuals previously infected with SARS-CoV-2

Mucosal Immunity in COVID-19: a neglected but critical aspect of SARS-CoV-2 infection

Mucosal vaccines-fortifying the frontiers