"I'm not sure when I will be able to get the vaccine."
- "I'm not sure when I will be able to get the vaccine."
"I'm not sure" 「わからない」
"I'm not sure" の代わりに "I don't know"も使えます。"I don't know when~"
"I will be able to get" 「受けれる」
"I will be able to get" の代わりに "I can get" も使えます。"I don't know when I can get~"