August 31, 2023 – Close and prolonged contact with someone who has COVID-19 can greater than quadruple the danger of contracting the virus, a brand new study confirms. There can be a better – but barely lower – risk in individuals who have been vaccinated, have had a previous infection, or each.
Led by health researchers at Yale University study was published this month within the magazine Nature communicationThe authors have looked into the subject because although vaccinations and former infections offer a certain level of protection against infection, the virus is typically still capable of circumvent immunity. Scientists speak of “leaky” protection.
The latest findings support the long-held theory that the likelihood of infection is determined by how much virus an individual is exposed to and for the way long.
Designing a study to guage this case is difficult, so the authors decided it will be best to conduct their study in 13 correctional facilities. The facilities were all positioned in Connecticut, and so they all usually conducted COVID testing on residents with and without symptoms. The researchers analyzed the danger of somebody contracting the virus based on where the person lived relative to an infected person, akin to living in the identical cell or cell block.
The likelihood of infection was also higher depending on whether an individual was vaccinated, had a previous infection, or each. The study took place from June 2021 to May 2022, when the Delta and Omicron virus variants were widespread. During this time, about 15,000 people spent not less than one night in a facility, 48% of individuals had accomplished the first vaccination course, and 27% received a booster shot.
The researchers found that in the course of the omicron period, individuals who shared a cell with an infected person had a virtually five-fold higher risk of also becoming infected, and other people living in the identical cell block had a virtually four-fold higher risk of infection. While previous infection, vaccination, or each reduced an individual's risk of developing COVID-19, individuals who shared a cell with an infected person still faced a significantly increased risk.
The authors wrote that the findings make a case for continued contact tracing, especially in places where people live closely together, akin to prisons or nursing homes. They said such tracing should include not only individuals who share a room, but additionally individuals who were together during leisure activities or at meals. The findings also pointed to the continued advantages of social distancing, quarantine and isolation, mask wearing, and improved ventilation and air circulation, they wrote.
Akiko Iwasaki, PhD, an immunobiologist at Yale who was not involved within the study, said Nature that the results of the study “just makes intuitive sense. But now there is evidence that this [measures] will probably be important for the immunity provided by the vaccine to work in you.”