UK study finds vaccinated people easily transmit Delta variant in households

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By Reuters
UK reports 40,004 new COVID-19 cases, 61 deaths - daily data
UK reports 40,004 new COVID-19 cases, 61 deaths - daily data   -   Copyright  Thomson Reuters 2021   -  

<div> <p><span class="caps">LONDON</span> – The Delta coronavirus variant can transmit easily from vaccinated people to their household contacts, a British study found on Thursday, although contacts were less likely to get infected if they were vaccinated themselves.</p> <p>The Imperial College London study illustrates how the highly transmissible Delta variant can spread even in a vaccinated population.</p> <p>The researchers underlined that did not weaken the argument for vaccination as the best way of reducing serious illness from <span class="caps">COVID</span>-19 and said booster shots were required.</p> <p>They found infections in the vaccinated cleared more quickly, but the peak viral load remained similar to the unvaccinated.</p> <p>“By carrying out repeated and frequent sampling from contacts of <span class="caps">COVID</span>-19 cases, we found that vaccinated people can contract and pass on infection within households, including to vaccinated household members,” Dr Anika Singanayagam, co-lead author of the study, said. </p> <p>“Our findings provide important insights into… why the Delta variant is continuing to cause high <span class="caps">COVID</span>-19 case numbers around the world, even in countries with high vaccination rates.”</p> <p>The study, which enrolled 621 participants, found that of 205 household contacts of people with Delta <span class="caps">COVID</span>-19 infection, 38% of household contacts who were unvaccinated went on to test positive, compared to 25% of vaccinated contacts.</p> <p>Vaccinated contacts who tested positive for <span class="caps">COVID</span>-19 on average had received their shots longer ago than those who tested negative, which the authors said was evidence of waning immunity and supported the need for booster shots. </p> <p>Imperial epidemiologist Neil Ferguson said that the transmissibility of Delta meant that it was unlikely Britain would reach “herd immunity” for long.</p> <p>“That may happen in the next few weeks: if the epidemic’s current transmission peaks and then starts declining, we have by definition in some sense reached herd immunity, but it is not going to be a permanent thing,” he told reporters.</p> <p>“Immunity wanes over time, it is imperfect, so you still get transmission happening, and that is why the booster programme is so important.” </p> <p/> </div>