The Department of Health and Social Care has confirmed the company has been given an indemnity protecting it from legal action as a result of any problems with the vaccine.
Ministers have also changed the law in recent weeks to give new protections to companies such as Pfizer, giving them immunity from being sued by patients in the event of any complications.
NHS staff providing the vaccine, as well as manufacturers of the drug, are also protected.
The vaccine will be made available to anyone over the age of 16 but will not be available to pregnant women because of the lack of data about how it could affect them and the baby. An ongoing trial is looking at this.
The Pfizer/BioNTech vaccine was authorised by the Medicines and Healthcare products Regulatory Agency on Tuesday under regulation 174 of the Human Medicine Regulations 2012 which allows an unlicensed medication to be used in an emergency such as a pandemic.
It also has the effect of granting civil immunity to Pfizer after the government changed the regulations following a short three-week consultation in September.