If anyone is waiting until the lowly crew is vaccinated with a western vaccine, it may be years before cruising resumes if ever. By the time enough vaccines are made, revaccinations will probably be required by those who've already had one or two.
At any rate, the Chinese vaccines may not prevent one from getting COVID (hence low efficacy), but apparently is apparently very good from allowing the infection to be anything other than a very mild case (prevents hospitalisations and severe cases)..
https://www.nytimes.com/interactive/...9-vaccine.html
https://www.bloomberg.com/news/artic...ize-up-sinovac