By John Chalmers and Philip Blenkinsop BRUSSELS (Reuters) -The EU welcomed more than 40 African leaders to Brussels on Thursday in an effort to reassert its influence on a continent where China and Russia have made hefty investment inroads, and where many felt let down by Europe’s COVID-19 vaccines rollout. The European Union will offer several packages of support at the summit to bolster health, education and stability in Africa, and will pledge half of a new 300 billion euro ($340.9 billion)investment drive launched to rival China’s Belt and Road Initiative. But the meeting also takes place …