Woo Taewoon and IONE, former members of the disbanded K-pop group SPEED have teamed up to release Vaccine on August 16, 2021. The song also features Apink's Yoon Bomi.
SPEED was the male subunit of MBK's group Co-Ed School and became an independent group in 2013. SPEED disbanded shortly after releasing Speed On, although Taewoon had left the group previous to the album's release.
Since his departure from SPEED, Taewoon has participated in several survival shows including Mix Nine and Show Me The Money, he also released two singles in 2016. Beyond his own music Taewoon has participated in writing songs for other musicians such as MAP6, Momoland, and most recently Apink.
On August 4, 2021 Million Market announced that IONE had signed with them making him label mates with Taewoon as well. Since SPEED's disbandment IONE has released several singles, his most recent being Idea which came out in 2019.
In addition to teaming up for this new song, IONE and Taewoon also have a collaborative TikTok account with former groupmate Choi Sungmin called RT Family where the three post dance covers.