MELBOURNE, June 18 (Reuters) - Australia"s top winter athletes will not be permitted to train or compete overseas in the lead-up to the 2022 Beijing Games unless vaccinated for COVID-19, the Olympic Winter Institute of Australia (OWIA) said on Friday. The policy is stricter than for Australia"s Tokyo-bound athletes, who are encouraged to get vaccines before the summer Olympics next month but not required to. "Winter athletes will be required to travel to multiple countries and multiple events in order to compete and to qualify," an OWIA spokesperson said. "Given the complexity of travel and timings with these different environments in winter months, this is a prudent risk management action to ensure the health and safety of OWIA-contracted athletes. "Vaccination for winter athletes provides an enormous level of comfort in ensuring athletes don"t become seriously ill when competing in multiple countries and locations where health services can be of vastly different standards." Melbourne"s The Age newspaper said the policy would affect about 30 contracted athletes. Athletes without OWIA contracts can still decline COVID-19 vaccines as a matter of personal choice. Australia made COVID-19 vaccination compulsory for the more than 180 athletes and officials heading to Japan for the Paralympics starting late August.