Signals of significantly increased vaccine breakthrough, decreased hospitalization rates, and less severe disease in patients with COVID-19 caused by the Omicron variant of SARS-CoV-2 in Houston, Texas (preprint)

Genetic variants of SARS-CoV-2 continue to dramatically alter the landscape of the COVID-19 pandemic. The recently described variant of concern designated Omicron (B.1.1.529) has rapidly spread worldwide and is now responsible for the majority of COVID-19 cases in many countries. Because Omicron was recognized very recently, many knowledge gaps exist about its epidemiology, clinical severity, and disease course. A genome sequencing study of SARS-CoV-2 in the Houston Methodist healthcare system identified 4,468 symptomatic patients with infections caused by Omicron from late November 2021 through January 5, 2022. Omicron very rapidly increased in only three weeks to cause 90% of all new COVID-19 cases, and at the end of the study period caused 98% of new cases. Compared to patients infected with either Alpha or Delta variants in our healthcare system, Omicron patients were significantly younger, had significantly increased vaccine breakthrough rates, and were significantly less likely to be hospitalized. Omicron patients required less intense respiratory support and had a shorter length of hospital stay, consistent with on average decreased disease severity. Two patients with Omicron “stealth” sublineage BA.2 also were identified. The data document the unusually rapid spread and increased occurrence of COVID-19 caused by the Omicron variant in metropolitan Houston, and address the lack of information about disease character among US patients.

The rapid reemergence of seasonal respiratory viruses in Houston, Texas, after relaxing COVID-19 restrictions (preprint)

Brief abstract Implementation of measures to limit the spread of the SARS-CoV-2 virus at the start of the COVID-19 pandemic resulted in a rapid decrease in all other respiratory pathogens. As COVID-19 containment measures were relaxed, the first non-COVID respiratory viruses to return to prepandemic levels were members of the rhinovirus/enterovirus, followed by the rapid return of seasonal coronaviruses, parainfluenza, and respiratory syncytial virus after the complete removal of COVID-19 precautions at the state level, including an end to mask mandates. Inasmuch as COVID-19 has dominated the landscape of respiratory infections since early 2020, it is important for clinicians to recognize the return of non-COVID respiratory pathogens may be rapid and significant when COVID-19 containment measures are removed.

Rapid, widespread, and preferential increase of SARS-CoV-2 B.1.1.7 variant in Houston, TX, revealed by 8,857 genome sequences (preprint)

Genetic variants of the SARS-CoV-2 virus have become of great interest worldwide because they have the potential to detrimentally alter the course of the SARS-CoV-2 pandemic, and disease in individual patients. We recently sequenced 20,453 SARS- CoV-2 genomes from patients with COVID-19 disease in metropolitan Houston (population 7 million), dating from March 2020 to early February 2021. We discovered that all major variants of concern or interest are circulating in the region. To follow up on this discovery, we analyzed 8,857 genome sequences from patients in eight Houston Methodist hospitals dispersed throughout the metroplex diagnosed from January 1, 2021 to March 7, 2021. This sample represents 94% of Houston Methodist cases and 4.8% of all reported cases in metropolitan Houston during this period. We discovered rapid, widespread, and preferential increase of the SARS-CoV-2 UK B.1.1.7 throughout the region. The estimated case doubling time in the Houston area is 6.9 days. None of the 648 UK B.1.1.7 samples identified had the E484K change in spike protein that can cause decreased recognition by antibodies.