LONDON (Reuters) - Britain will start rolling out the COVID-19 vaccine developed by Pfizer and BioNTech on Tuesday, the first Western country to begin vaccinating its population against infection from the new coronavirus. Britain has ordered 40 million doses of the Pfizer vaccine - enough for just under a third of the population as two shots of the shot are needed per person to gain immunity. Below are details on what the government, companies and health service have said about the manufacturing and storage process, logistics of the rollout, who gets the vaccine and where they will get it. MANUFACTURING PROCESS: - The vaccine needs to be shipped and stored at minus 70 degrees Celsius (-94F) or below. - The two companies have developed specially designed, temperature-controlled shippers which can maintain their temperature for 10 days unopened. The shippers can also be used for storage, maintaining the required temperature, for a further 30 days. - Once thawed, the vaccine vial can be stored for up to five days at refrigerated temperatures (2-8 degrees Celsius). - The UK market will be supplied by Pfizer’s manufacturing site in Puurs, Belgium, one of its largest sterile injectable sites. LOGISTICAL DETAILS: - Pfizer dispatched initial volumes of vaccine from Belgium, which arrived at secure locations in Britain by the weekend. Around 800,000 doses are expected to be available in the first week of rollout. - After arriving, there is a post-delivery quality assurance process to ensure the vaccine’s quality and integrity has been maintained through transit, which can take 12-24 hours. - Each box is then opened and unpacked manually, with temperature data downloaded from each box. - There are five packs of 975 doses per box. Only sites with the right regulatory licence can split the vaccine packs, which limits where they can be sent in the first instance. WHICH PEOPLE GET IT WHEN? - Britain has said the speed of the rollout then depends on how fast Pfizer can manufacture and deliver the vaccine. - It will be administered in two shots, about three weeks apart. The bulk of the rollout will happen in the new year. - Older care home residents and their carers will be the highest priority to receive the vaccine, followed by those over 80 years of age and frontline health workers, according to the chair of the Joint Committee on Vaccination and Immunisation (JCVI). - People in descending bands from 80 to 50 will follow on in the first wave, along with people aged 16 years to 64 years with underlying health conditions which put them at higher risk of serious disease and mortality. WHERE WILL PEOPLE GET IT? - Britain will use hospitals, large vaccination centres and community medical centres to distribute the vaccine. - At first, the vaccine will be available from around 50 “Hospital Hubs”, where shots will be defrosted and then prepared. - Over 1,000 local vaccination centres, operated by groups of general practitioners (GPs), will then open. The health service has asked doctors to be ready to begin vaccinations from Dec. 14. - When there is more vaccine and it is possible to split the packs up, the government has said it plans bigger vaccination centres and smaller arrangements through local pharmacies.