Although it was initially thought that two injections would be required, clinical trials showed that the new vaccine protected adults "with only one dose instead of two", and so the limited vaccine supplies would go twice as far as had been predicted.
尽管最初有人认为需注射两剂疫苗才能见效，但临床试验表明新型疫苗“仅需一剂就能保护成年人，而非两剂”，因此一旦被预言，就会给每人限量供应两剂疫苗。