0
0
A recent study from the University of East Anglia has revealed that face masks did not significantly lower the risk of Covid-19 infection following the initial Omicron wave. The findings, published in PLOS ONE, underscore the need for adaptable public health strategies and continuous research as Covid-19 risk factors evolve.
Changing Risk Factors with Omicron Variant
The research, led by Professor Paul Hunter and Dr. Julii Brainard from UEA’s Norwich Medical School, analyzed official data from the Office for National Statistics (ONS) Covid survey in England. The study focused on the period from November 2021 to May 2022, capturing the shift in dominant Covid variants from Delta to Omicron in December 2021.
Professor Hunter explained, “Early in the pandemic, many studies identified risk factors for catching Covid. However, fewer studies have been conducted after the first year. Our research shows notable changes in risk factors around the time the Omicron BA.2 variant became dominant.”
Key Findings from the Data
The analysis revealed several key changes in infection risk factors during the study period:
- Face Masks: Initially, always wearing face masks at work, school, or in enclosed spaces was associated with a reduced risk of infection. However, this protective effect diminished after the first Omicron wave.
- Household Size: Living in larger households was a risk factor early on, but by the end of the study, the risk was similar regardless of household size.
- Overseas Travel: Early in the pandemic, overseas travel did not increase risk, but it became a significant risk factor later.
- Employment in Health or Social Care: Working in these sectors was not linked to a higher risk of infection during the study period, despite being critical early in the pandemic.
- Ethnic Minority Status: Initially a strong risk factor, being of an ethnic minority was associated with a lower risk as the study progressed.
- Retirement: Retired individuals had a reduced risk compared to those working, but this protective effect disappeared by late February 2022.
- Contact with Children: By the end of February 2022, the risk for adults living with children decreased.
- Living with Elderly Individuals: Initially protective, living with someone aged 70 or older no longer reduced infection risk by mid-February 2022.
Implications for Public Health Strategies
The study highlights the complexity of managing Covid-19 infection risks, especially as new variants emerge. Dr. Brainard noted, “Management of infection risk needs to be agile, adapting to epidemic developments and better-quality information. To prevent infections, we need to understand which factors are most relevant and recognize that these factors can change.”
Need for Ongoing Research
While the study confirms that face masks and other measures can reduce transmission, the extent of their effectiveness varies with different variants. The researchers emphasized the importance of continued research to adapt public health strategies effectively.
Professor Hunter concluded, “It should not be surprising that risk factors change during a pandemic. As Covid-19 becomes endemic, the factors driving infection rates evolve, and public health responses must evolve accordingly.”
This study underscores the dynamic nature of Covid-19 and the need for flexible, evidence-based approaches to managing its spread.
Reference: “Changing risk factors for developing SARS-CoV-2 infection from Delta to Omicron” by Paul R. Hunter and Julii Brainard, 15 May 2024, PLOS ONE.
