A statement on the findings said that protection is achieved 28 days after the initiation of the vaccination schedule, which consists of two doses administered three weeks apart.
The vaccine has been tested on 43,538 volunteers in six countries and no safety concerns have been raised. The 90% figure is based on the first 94 volunteers to develop COVID-19.
The team behind the vaccine say they will have enough safety data by the third week of November to submit the vaccine for emergency regulatory approval. They say they 'expect to produce globally up to 50m vaccine doses in 2020 and up to 1.3bn doses in 2021', suggesting some doses could become available this year in the UK.
Hospital staff and care home workers are likely to be prioritised for vaccination, along with the elderly who are most at risk of severe disease.
Professor Ugur Sahin, BioNTech co-founder and chief executive called the findings 'a victory for innovation, science and a global collaborative effort'.
'When we embarked on this journey 10 months ago this is what we aspired to achieve. Especially today, while we are all in the midst of a second wave and many of us in lockdown, we appreciate even more how important this milestone is on our path towards ending this pandemic and for all of us to regain a sense of normality.
'We will continue to collect further data as the trial continues to enroll for a final analysis planned when a total of 164 confirmed COVID-19 cases have accrued.'
Experts hailed the findings but pointed out that the precise efficacy of the vaccine may change when the full results are analysed. They also highlighted that questions over the vaccine's efficacy in high-risk elderly people and the duration of protection remain to be answered.
The results come days after the BMA and NHS England confirmed a deal for GP practices across England to deliver COVID-19 vaccinations potentially from as early as the start of December.
NHS England has said it expects vaccines are more likely to become available from the start of 2021, but has put the deal in place with GPs on the 'offchance' of some doses becoming available sooner.
The Pfizer/BioNTech vaccine is the first of around a dozen COVID-19 vaccines in phase 3 trials to show results and would be the first RNA vaccine ever approved. Unlike the other advanced-stage vaccines, it has to be kept in ultra-cold storage at below -80C.