A Review of the Science

Exercise and vitamin D3 are beneficial, omicron is mild in children, asymptomatic spread with Omicron is significant

Covid-19: Omicron variant is linked to steep rise in hospital admissions of very young children BMJ(Published 14 January 2022) BMJ2022;376:o110

Highlights:

• The overall conclusions of this article do not match the fearful messaging of the title.
  Hospital admissions of children under 1 year old have risen steeply, coinciding with transmission of the omicron variant

• The alpha and delta variants were also associated with increased cases in children, raising concerns that children would be more vulnerable to these variants and would become sicker. But this turned out not to be the case.

• And the indications are that children admitted to hospital with omicron are even less sick, as they require less support than children admitted earlier in the pandemic and are discharged earlier.

  • Oxygen use by children aged under 1 admitted in the past four weeks for whom data are available was 12%, compared with 22.5% in the first wave of the pandemic.

  • Admission to intensive care was 9.9% (v 14%),

  • Use of mechanical ventilation was 2% (v 5.8%),

  • Use of non-invasive ventilation was 2% (v 7.2%), and mean length of stay was 1.7 days (v 6.6 days).

• A rapid review by NHS England of 55 babies admitted to hospital with omicron found that most were aged under 3 months and that around half were admitted for observation and received no treatment, “Clinically, this picture is incredibly reassuring,”

• Camilla Kingdon, president of the Royal College of Paediatrics and Child Health, said, “As pediatricians, we are accustomed to having busy winters where we see lots of particularly under 1s, typically, with high fevers, often with some kind of respiratory distress.”

• She noted an increase in babies testing positive for omicron but lots of other respiratory viruses also circulating. “The presentation of these babies very much fits in with a mix of what we would expect to see in a busy winter in the UK,” she said.

• Kingdon added that South Africa had also seen a sharp rise in hospital admissions of under 5s associated with omicron but that most had not needed supportive care and had required a shorter length of stay.

• The CDC explained that many children were admitted with covid-19 rather than because of it.

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High Rate of Asymptomatic Carriage Associated with Variant Strain Omicron medRXiv January 14, 2022 (not yet peer reviewed)

Highlights:

• Findings of this study strongly suggest that Omicron has a much higher rate of asymptomatic transmission (infectivity) than other variants and this high prevalence of asymptomatic infection is likely a major factor in the widespread, rapid dissemination of the variant globally, even among populations with high prior rates of SARS-COV-2 infection.

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Does Regular Exercise Counter T Cell Immunosenescence Reducing the Risk of Developing Cancer and Promoting Successful Treatment of Malignancies? Oxid Med Cell Longev. 2017;2017:4234765. doi: 10.1155/2017/4234765. Epub 2017 Jul 2. PMID: 28751932; PMCID: PMC5511671.

Highlights:

• Moderate intensity aerobic exercise training or regular physical activity is beneficial for immune function.

• For example, some evidence shows that individuals with an active lifestyle exhibit stronger immune responses to vaccination compared to those who are inactive. Encouragingly, poor vaccine responses, which are characteristic of an aging immune system, can be improved by single or repeated bouts of exercise (by association, exercise will also improve the immune system overall).

• In addition, exercise-induced lymphocytosis, and the subsequent lymphocytopenia, is thought to facilitate immune surveillance, whereby lymphocytes search tissues for antigens derived from viruses, bacteria, or malignant transformation.

• Aerobic exercise training is anti-inflammatory and is linked to lower morbidity and mortality from diseases with infectious, immunological, and inflammatory etiologies, including cancer.

• These observations have led to the view that aerobic exercise training might counter the age-associated decline in immune function, referred to as immunosenescence.

• This article summarizes the aspects of immune function that are sensitive to exercise-induced change, highlighting the observations which have stimulated the idea that aerobic exercise training could prevent, limit, or delay immunosenescence, perhaps even restoring aged immune profiles.

• These potential exercise-induced anti-immunosenescence effects might contribute to the mechanisms by which active lifestyles reduce the risk of developing cancer and perhaps benefit patients undergoing cancer therapy.

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Vitamin D Status and SARS-CoV-2 Infection and COVID-19 Clinical Outcomes. Front Public Health. 2021 Dec 22;9:736665. doi: 10.3389/fpubh.2021.736665. PMID: 35004568; PMCID: PMC8727532.

Highlights:

• The aim of the present meta-analysis was to investigate whether vitamin D status is associated with the COVID-19 severity, defined as ARDS requiring admission to intensive care unit (ICU) or mortality (primary endpoints) and with the susceptibility to SARS-CoV-2 and COVID-19-related hospitalization (secondary endpoints).

• Methods: A search in PubMed, ScienceDirect, Web of Science, Google Scholar, Scopus, and preprints repositories was performed until March 31th 2021 to identify all original observational studies reporting association measures, or enough data to calculate them, between Vitamin D status (insufficiency <75, deficiency <50, or severe deficiency <25 nmol/L) and risk of SARS-CoV-2 infection, COVID-19 hospitalization, ICU admission, or death during COVID-19 hospitalization.

• Fifty-four studies (49 as fully-printed and 5 as pre-print publications) were included for a total of 1,403,715 individuals.

• The association between vitamin D status and SARS-CoV2 infection, COVID-19 related hospitalization, COVID-19 related ICU admission, and COVID-19 related mortality was reported in 17, 9, 27, and 35 studies, respectively.

• Severe deficiency, deficiency and insufficiency of vitamin D were all associated with ICU admission SARS-CoV-2 infection and COVID-19 hospitalization.

• Considering specific subgroups (i.e., Caucasian patients, high quality studies, and studies reporting adjusted association estimates) the results of primary endpoints did not change.

• Interpretations: Patients with low vitamin D levels present an increased risk of ARDS (COVID-19 severity) requiring admission to intensive care unit (ICU) or mortality due to SARS-CoV-2 infection and a higher susceptibility to SARS-CoV-2 infection and related hospitalization.