Many countries around the world recommend that people wear masks in public as part of their strategy to curb the pandemic. We look at why some people do not wear masks and discuss what scientific evidence says about wearing them.
Since the start of the COVID-19 pandemic, scientists and other experts have debated whether the general public should wear face masks and whether these masks should be medical grade masks or homemade face coverings.
From early April onwards, the Centers for Disease Control and Prevention (CDC) in the United States recommended that people wear homemade face coverings in places where physical distancing is impossible. Other countries, such as the United Kingdom and Germany, have made wearing a face covering on public transport mandatory.
The World Health Organization (WHO) long shied away from such recommendations, maintaining that only healthcare professionals, those who currently have the new coronavirus, as well as those caring from them at home, wear medical grade masks.
But in early June, the WHO released a list of recommendations suggesting the most appropriate types of masks to wear in a variety of settings. This included the use of non-medical masks in crowded places and public transport. Claims: Masks are not an effective way of protection from the new coronavirus, only N95 are, and masks have disclaimers saying they cannot prevent someone from acquiring the new coronavirus
These claims represent the essence of the argument around whether to wear a mask. The primary aim of asking the general public to wear masks where physical distancing is not possible is not to protect the wearer. Rather than protecting the wearer, source control seeks to block the release of virus-laden droplets into the air that surrounds the person wearing the mask.
‘No evidence’ that vitamin D can prevent or treat COVID-19
A review from health experts in the United Kingdom has found no evidence that vitamin D deficiency is an independent risk factor for COVID-19. However, the country’s National Health Service recommend taking a daily vitamin D supplement to compensate for any lack of sunlight exposure during lockdown.
Vitamin D is vital for maintaining healthy bones and muscles. There is also some evidence that it may help protect against viral respiratory infections and play a regulatory role in the body’s immune response.
This has led to a proposal that taking vitamin D supplements could help prevent or even treat COVID-19, the primarily respiratory disease caused by the virus SARS-CoV-2.
However, a review of five of these studies by the U.K.’s National Institute for Health and Care Excellence (NICE), which compiles guidelines on best practices, concludes that the studies provide no evidence that vitamin D levels influence the risk of getting COVID-19 or dying as a result.
None of the five studies had been designed to investigate the effects of the supplements on the risk of the infection or as a treatment for the disease, the authors point out. Either investigation would have required an intervention study, such as a randomized controlled trial.
The existing studies, therefore, provide no insights into the vitamin’s efficacy, appropriate doses, or possible adverse effects as a means of treating or preventing COVID-19.
Moreover, only one study in the review accounted for confounding factors, which may provide alternative explanations for the observed associations between vitamin D status and COVID-19.
Higher body mass index (BMI), older age, and socioeconomic deprivation, for example, are all factors that could affect both the risk of COVID-19 and levels of the vitamin.
This makes it impossible to draw any firm conclusion about whether having a lack of the vitamin increases the risk of contracting the virus that causes COVID-19 or dying as a result of the disease.
One of the studies, found an association between average levels of vitamin D and numbers of COVID-19 cases and deaths by country. But the research had limitations — it did not, for example, account for the proportions of older people in these populations.