The preprint landscape, January 10, 2022
A number of significant preprint articles came out recently with good scientific design and important conclusions. Below are a few:
BACKGROUND Natural SARS-CoV-2 infection elicits strong protection against reinfection with the Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2) variants. However, the Omicron (B.1.1.529) variant harbors multiple mutations that can mediate immune evasion. We estimated effectiveness of prior infection in preventing reinfection (PES) with Omicron and other SARS-CoV-2 variants in Qatar.
- Protection afforded by prior infection in preventing symptomatic reinfection with Alpha, Beta, or Delta is robust, at about 90%.
- While such protection against reinfection with Omicron is lower, it is still considerable at nearly 60%.
- Prior-infection protection against hospitalization or death at reinfection appears robust, regardless of variant.
Although this study is not a head to head comparison of natural immunity versus vaccine induced immunity, it does suggest that protection afforded by natural infection is superior to vaccine induced immunity.
Effectiveness of COVID-19 vaccines against Omicron or Delta infection medRxiv Jan 1, 2022 doi: https://doi.org/10.1101/2021.12.30.21268565
Methods Applying the test-negative design to linked provincial data, we estimated vaccine effectiveness against infection (irrespective of symptoms or severity) caused by Omicron or Delta between November 22 and December 19, 2021. We included individuals who had received at least 2 COVID-19 vaccine doses (with at least 1 mRNA vaccine dose for the primary series) and used multivariable logistic regression to estimate the effectiveness of two or three doses by time since the latest dose.
(The study included 3,442 Omicron-positive cases, 9,201 Delta-positive cases, and 471,545 test-negative controls).
- In contrast, receipt of 2 doses of COVID-19 vaccines was not protective against Omicron.
- Vaccine effectiveness against Omicron was 37% (95%CI, 19-50%) ≥7 days after receiving an mRNA vaccine for the third dose.
Updated projections for COVID-19 omicron wave in Florida. medRxiv Jan 6, 2022 doi: https://doi.org/10.1101/2022.01.06.22268849
In this report, the authors use a detailed simulation model to assess and project the COVID-19 epidemic in Florida. The model is a data-driven, stochastic, discrete-time, agent based model with an explicit representation of people and places.
- Using the model, the authors find that the omicron variant wave in Florida is likely to cause many more infections than occurred during the delta variant wave.
- Due to testing limitations and often mild symptoms, it is anticipated that omicron infections will be underreported compared to delta.
- They project that reported cases of COVID-19 will continue to grow significantly and peak in early January 2022
- That the number of reported COVID-19 deaths due to omicron may be 1/3 of the total caused by the delta wave.
Lifestyle changes during the coronavirus disease 2019 pandemic impact metabolic dysfunction-associated fatty liver disease. Liver International. 07 January 2022 (peer reviewed)
The coronavirus disease 2019 (COVID-19) pandemic precipitated lifestyle changes. The authors aimed to clarify whether COVID-19–induced lifestyle changes affected the development of metabolic dysfunction–associated fatty liver disease (MAFLD).
Metabolic associated fatty liver disease (MAFLD) affects 20-30% of the worldwide population and is becoming the most common cause of chronic liver disease, cirrhosis and hepatocellular carcinoma (HCC). MAFLD is the hepatic expression of metabolic dysfunction correlated with a variety of metabolic comorbidities including obesity, dyslipidemia, hypertension and type 2 diabetes (T2DM).:
This retrospective longitudinal study included 973 participants who underwent health checkups between 2018 and 2020. Participants’ clinical characteristics and lifestyle habits were investigated. Independent lifestyle predictors of MAFLD development before the pandemic (2018–2019) and during the pandemic (2019–2020) were identified using logistic regression analysis.
- In 2018, 261 (27%) patients were diagnosed with MAFLD. Before the pandemic, 22 patients developed new MAFLD. During this time,
- Routine late-night meals were identified as an independent lifestyle predictor of MAFLD development (hazard ratio [HR] 2.54, 95% confidence interval [CI] 1.02–6.36, P=0.046). In contrast, 44 patients developed new MAFLD during the pandemic.
- During this time, higher daily alcohol intake was identified as an independent lifestyle predictor of MAFLD development (HR 1.03, 95% CI 1.01–1.05, P=0.008).
- In participants aged <60 years, daily alcohol intake and the proportion of participants who ate 2 times/day were significantly higher in patients who developed MAFLD during the pandemic than in those who did not.
New MAFLD diagnoses increased during the COVID-19 pandemic. Changes in lifestyle factors, particularly in those aged <60 years, must be monitored and addressed as the pandemic continues.
Basically, this study suggests that people are eating and drinking more – leading to unhealthy lifestyle changes. What was not answered was whether this was due to remote employment, lock downs, stress or some other cause.
The risk between morbid obesity and severe COVID-19 outcomes is real. More public education and research is needed in this topic area.
Other interesting news items on the web:
The Wall Street Journal has an excellent opinion piece, written by my good friends Dr. Luc Montagnier and Jed Rubenfeld
Jan. 9, 2022 5:20 pm (Illustration: David Gothard)