SHANGHAI, Dec 24 (Reuters) - China, grappling with a new wave of COVID-19 infections, took another step towards loosening its pandemic-related restrictions on Saturday when Hong Kong's leader announced it would aim to re-open its borders with the mainland by mid-January.Speaking at a news conference upon returning from Beijing, Hong Kong Chief executive John Lee said authorities would aim to "gradually, orderly, and fully" re-open all entry points between the two sides, and coordinate with the government of nearby Shenzhen to manage the flow of people."My friends are basically all positive, and all have basically recovered," said Liu Yang, 23, an IT worker attending the market.Bloomberg News reported on Friday that nearly 37 million people may have been infected with COVID on a single day this past week, citing estimates from the government's top health authority.The surge has strained the medical sector, in particular blood repositories, as a lack of donors has caused reserves to dwindle."