Såg en intressant text i New England Journal of Medicine, där författarna menar att data tyder på att personer med munskydd inte blir lika kraftigt/allvarligt sjuka som de som smittats utan att ha munskydd. Tidigare har det ju noterats att de som av olika skäl fått i sig stora virusmängder (inte minst vårdpersonal) också oftare blivit allvarligt sjuka. Därför kan det ju tänkas att ett munskydd minskar mängden virus, och därmed ger upphov till en mildare infektion.
"In an outbreak on a closed Argentinian cruise ship, for example, where passengers were provided with surgical masks and staff with N95 masks, the rate of asymptomatic infection was 81% (as compared with 20% in earlier cruise ship outbreaks without universal masking). In two recent outbreaks in U.S. food-processing plants, where all workers were issued masks each day and were required to wear them, the proportion of asymptomatic infections among the more than 500 people who became infected was 95%, with only 5% in each outbreak experiencing mild-to-moderate symptoms. Case-fatality rates in countries with mandatory or enforced population-wide masking have remained low, even with resurgences of cases after lockdowns were lifted."
Artikelförfattarna spekulerar även om inte denna typ av milda infektioner skulle kunna höja den allmänna immuniteten mot Covid-19 i samhället.
"While we await the results of vaccine trials, however, any public health measure that could increase the proportion of asymptomatic SARS-CoV-2 infections may both make the infection less deadly and increase population-wide immunity without severe illnesses and deaths. Reinfection with SARS-CoV-2 seems to be rare, despite more than 8 months of circulation worldwide and as suggested by a macaque model. The scientific community has been clarifying for some time the humoral and cell-mediated components of the adaptive immune response to SARS-CoV-2 and the inadequacy of antibody-based seroprevalence studies to estimate the level of more durable T-cell and memory B-cell immunity to SARS-CoV-2. Promising data have been emerging in recent weeks suggesting that strong cell-mediated immunity results from even mild or asymptomatic SARS-CoV-2 infection, so any public health strategy that could reduce the severity of disease should increase population-wide immunity as well."
/M