China's been closed to foreign tourism for three years, but today that's all changed. As of today, China will begin issuing all types of visas again, including tourist visas. They also have begun letting folks with tourist visas enter again, so long as their visas aren't yet expired.
It's also worth noting that visa-free tourism to the island of Hainan and for passengers aboard cruise ships visiting Shanghai has been reintroduced.
Unlike most of the other reopenings we've seen around the world, though, just proof of vaccination against COVID won't be sufficient to enter China. You'll need a negative COVID test taken within the last 48 hours, and the results must be stated in your customs declaration form.