The Australian government has secured an additional 20 million doses of the Pfizer vaccine as it steers away from relying on the AstraZeneca vaccine after a rare but serious blood clotting side effect was discovered. The announcement comes after Prime Minister Scott Morrison called for an urgent press conference on Thursday night to provide new health advice to Australians aged under 50 regarding receiving the AstraZeneca jab. The additional doses, scheduled to arrive in the fourth quarter of the year, means Australia will receive a total of 40 million Pfizer doses. “Safety remains our top priority, as it has been throughout the pandemic, and we will continue to follow the best medical advice in protecting Australians,” Morrison wrote in a post on Facebook. The switch away from the AstraZeneca vaccine comes after European Medicine Agency found “possible links” between the vaccine and an extremely rare but serious blood clot. Australian …