Epidemiology of Infections with SARS-CoV-2 Omicron BA.2 Variant, Hong Kong, January–March 2022

Abstract

Our analysis of data collected from multiple epidemics in Hong Kong indicated a shorter serial interval and generation time of infections with the SARS-CoV-2 Omicron variant. The age-specific case-fatality risk for Omicron BA.2.2 case-patients without complete primary vaccination was comparable to that of persons infected with ancestral strains in earlier waves.

Vaccine effectiveness of BNT162b2 and CoronaVac against SARS-CoV-2 Omicron BA.2 infection, hospitalisation, severe complications, cardiovascular disease and mortality in patients with diabetes mellitus: A case control study

“…This case-control study extracted data using the population-level electronic health databases from Hong Kong Hospital Authority (HA) and the Department of Health (DH) of the Government of the Hong Kong Special Administrative Region, China in Hong Kong, China and enrolled DM patients aged ≥12 years, who had received zero to three doses of BNT162b2 or CoronaVac, during January to March 2022. This period was principally driven by the Omicron BA.2 variant ( 2 ), and these databases have previously been applied in several COVID-19 pharmacovigilance studies ( [3] , [4] , [5] , [6] ). Those who had a previous COVID-19 infection before the index date or had received the fourth dose of COVID-19 vaccine were excluded from the analysis.…”

Acute pulmonary emboli following rebound phenomenon after Nirmatrelvir/Ritonavir treatment for COVID-19

“…In testament, a retrospective cohort Hong Kong study of 5663 people infected during the Omicron BA.2.2. wave found the efficacy of Nm/R therapy to reduce hospitalization to be 53% in comparison to the 88% reduction demonstrated in the Nm/R trial [ 5 , 6 ]. Further, high profile individuals such as Anthony Fauci have elected for additional Nm/R therapy when experiencing rebound symptoms [ 6 ].…”

Slow waning of antibodies following a third dose of BNT162b2 in adults who had previously received two doses of inactivated vaccine

“…Our study had a number of limitations. A large wave of Omicron BA.2 occurred in Hong Kong in February-April 2022 with more than 1 million confirmed cases (14% of the population) and 9000 deaths (1.2 deaths per 1000 persons) [21]. Many infections likely were undocumented.…”