By Jeff Mason WASHINGTON (Reuters) – President Joe Biden is expected on Thursday to lay out a new goal for U.S. vaccinations against COVID-19 at his first formal White House news conference, where topics will likely include immigration, infrastructure, gun control and foreign relations. Biden, who has taken questions from reporters in other settings since taking office on Jan. 20, may face sharp queries on a recent rise in asylum seekers at the U.S.-Mexico border, plans to share coronavirus vaccines with other countries, and efforts to keep Americans safe from mass shootings. Aides have been d…