Abstract
The novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) and the associated coronavirus disease 2019 (COVID-19) continue to spread throughout the world, with >265 million total confirmed cases (1). As of today 55.2% of the world population has received at least one dose of a COVID-19 vaccine, 8.24 billion doses have been administered globally, and 33.99 million are now administered each day (4).
However, the number of new COVID-19 cases continues to increase everywhere in Europe, in Italy as of today January 9, 2022, 197,000 COVID-19–positive cases were detected (5). From December 1, 2021, until January 8, 2022, 16,030 nasopharyngeal swab tests were processed in Altamedica laboratory by real-time reverse transcription polymerase chain reaction analysis, of which 2,526 (15.7%) resulted COVID-19 positive.
Among the 2,526 positive cases, 2,071 (82%) were vaccinated, and 455 (18%) were unvaccinated. In particular, 1,739 (84%) cases received 1 or 2 doses of vaccine, and 332 (16%) were people who received the booster dose. Based on collected data, 1,387 (67%) vaccine breakthrough infections were asymptomatic, 590 (28.5%) were paucisymptomatic, and 93 (4.5%) were symptomatic presenting fever >38°C or other symptoms, no hospitalization occurred. Among positive cases who were unvaccinated, 32 (7%) were symptomatic presenting fever >38°C or other symptoms, and none needed to be hospitalized (Fig. 1).
From December 1, 2021, until January 8, 2022, 16,030 nasopharyngeal swab tests were processed, of which 2,526 (15.7%) resulted COVID-19 positive. Among the 2,526 positive cases, 1,387 (67%) were asymptomatic.
To characterize SARS-CoV-2 variants, we genotyped SARS-CoV-2–positive swab samples by quantitative polymerase chain reaction analysis using TaqMan probes (2). The developed custom genotyping panel probes differentiate between the alpha, beta, gamma, delta, and omicron, all B.1 derived variants (all carrying D614G mutation) from the A.1 (Wuhan) lineage (Table 1).
Frequency of Genotyping of Some Variants of SARS-CoV-2 in Italy Among 50 Cases Per Week
Our data, support the evidence that COVID-19 severity is reducing toward a milder flu-like disease affecting both vaccinated and nonvaccinated people, obviously vaccinated people are now more affected only because their number is greater. Moreover, we noticed that our internal survey regarding the variants of concern distribution reported frequency of omicron variants much higher than the frequency reported by the National Institute of Health until December 9 (3).