If you listen to Dr. Tegnell carefully, you will understand that a "second wave" is a result of lock down and reopening. A rebound effect. It is natural for a increase spike to occur after a lockdown.

"The Democrat Party looks like Titanic survivors. Partying and celebrating one moment, and huddled in lifeboats freezing the next". Hatari 2017

"Hokey religions and ancient weapons are no match for a good blaster at your side, kid." Han Solo