key: cord-0744959-rsqj20zs
authors: Mattiuzzi, Camilla; Henry, Brandon M.; Lippi, Giuseppe
title: COVID-19 vaccination and SARS-CoV-2 Omicron (B.1.1.529) variant: a light at the end of the tunnel?
date: 2022-03-09
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2022.03.008
sha: 3bbe8d70f45fdd123c9ceb3ee2af32654d31d3c9
doc_id: 744959
cord_uid: rsqj20zs

We retrieved data from the on-line database of the Italian Ministry of Health concerning the previous and ongoing epidemic waves of SARS-CoV-2 in Italy, analyzing prevalence of variants, number of SARS-CoV-2 diagnoses, hospitalization and intensive care unit (ICU) admissions for coronavirus disease 2019 (COVID-19). Two similar days were compared, i.e., January 12, 2021 and January 12, 2022. Although the number of positive cases in 2022 was hence nearly 4-fold higher compared to the same period in 2021, presumably due to higher transmissibility of the Omicron variant, a considerable decrease of COVID-19 related hospitalizations (-82%) and ICU admissions (-84%) could be observed in the more recent period, when the Omicron variant was largely prevalent and COVID-19 vaccination was widespread.

We retrieved data from the on-line database of the Italian Ministry of Health concerning the previous and ongoing epidemic waves of SARS-CoV-2 in Italy, analyzing prevalence of variants, number of SARS-CoV-2 diagnoses, hospitalization and intensive care unit (ICU) admissions for coronavirus disease 2019 . Two similar days were compared, i.e., January 12, 2021 and January 12, 2022. Although the number of positive cases in 2022 was hence nearly 4-fold higher compared to the same period in 2021, presumably due to higher transmissibility of the Omicron variant, a considerable decrease of COVID-19 related hospitalizations (-82%) and ICU admissions (-84%) could be observed in the more recent period, when the Omicron variant was largely prevalent and COVID-19 vaccination was widespread.

To the Editor, We read with interest the recent article of Abdullah and co-authors, who concluded that significantly lower severity of illness associated with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Omicron B.1.1.529 variant-driven epidemic wave has been observed in the Tshwane, South Africa (Abdullah et al., 2021) .

This evidence follows that recently published in other studies from South-Africa, US and UK (Mahase, 2021) , which also reported a similar suggestion of decreased pathogenicity associated with this new and highly mutated Omicron variant (Lippi, Mattiuzzi and Henry, 2021) .

To corroborate these preliminary findings, we retrieved data available in the on- vaccination rate: 86.6%) was 570040 and 2222060, respectively. Although the number of positive cases in 2022 was hence nearly 4-fold higher compared to the same period in 2021, presumably due to higher transmissibility of the Omicron variant (Lippi, Mattiuzzi and Henry, 2021) , a considerable decrease of COVID-19 related hospitalizations (-82%) and ICU admissions (-84%) could be observed in the more recent period, when the Omicron variant was largely prevalent and COVID-19 vaccination was widespread (Table 1) 

This work received no funding.

The authors declare no conflict of interest.

Unnecessary (electronic search on freely available database).

X The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: 

COVID-19 vaccination and SARS-CoV-2 Omicron (B.1.1.529) variant: a light at the end of the tunnel?

Service of Clinical Governance

Division of Nephrology and Hypertension, Cincinnati Children's

Disease Intervention & Prevention and Population Health Programs

Decreased severity of disease during the first global omicron variant covid-19 outbreak in a large hospital in tshwane, south africa

Covid-19 -Situazione in Italia

Updated picture of SARS-CoV-2 variants and mutations. Diagnosis (Berl)

Covid-19: Hospital admission 50-70% less likely with omicron than delta, but transmission a major concern

None.