"An important consideration from these findings is how to make young people who think they are not prone to COVID-19 to be still engaging in proactive behaviours against the virus," said Associate Professor Edson Tandoc Jr.
Interim results of the Oxford Covid-19 vaccine trials found that the vaccine protects against symptomatic disease in 70 per cent of cases with vaccine efficacy of 62 per cent for those given two full doses, and of 90 per cent in those given a half then a full dose.
According to the study, published in 'Behavioural Ecology', as a pathogen spreads across a population, changes in social behaviour can alter how the disease spreads
Trump later said that the US had the 'greatest economy ever' before the COVID-19 outbreak hit the country further. He also termed the virus "as an artificial horrible situation".
Amazon had earlier tried to play down the importance of sharing data on how the pandemic affected workers, despite criticism from current and former employees over the protection measures put in place by the e-commerce giant.