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This section is part 4 of the PHE UK immunisation schedule.

  • For a variety of reasons, some individuals may present not having received some or all of their immunisations or may have an unknown immunisation history. Where an individual born in the UK presents with an inadequate immunisation history, every effort should be made to clarify what immunisations they may have had.
  • Anyone who has not completed the routine immunisation programme as appropriate for their age should have the outstanding doses as described in the relevant chapters.
  • If children and adults coming to the UK do not have a documented or reliable verbal history of immunisation, they should be assumed to be unimmunised and a full course of required immunisations should be planned.
  • Individuals coming from areas of conflict or from population groups who may have been marginalised in their country of origin (e.g. refugees, gypsy or other nomadic travellers) may not have had good access to immunisation services.
  • In particular, older children and adults may also have been raised during periods before immunisation services were well developed or when vaccine quality was sub-optimal.
  • Where there is no reliable history of previous immunisation, it should be assumed that any undocumented doses are missing and the UK catch-up recommendations for that age should be followed.
  • An algorithm for vaccinating individuals with uncertain or incomplete immunisation status is available from the Vaccination of individuals with uncertain or incomplete immunisation status page.
  • Individuals coming to the UK who have a history of completing immunisation in their country of origin may not have been offered protection against all the antigens currently offered in the UK.
  • Most countries have offered protection against diphtheria, tetanus, polio and whooping cough for many years, but do not currently include MenC or MenB in the schedule and may have introduced pneumococcal conjugate vaccine and Haemophilus influenzae type b (Hib) vaccine relatively recently.
  • Many countries worldwide only offer single measles vaccines, rather than measles, mumps, and rubella (MMR), or have only recently started to offer a rubella containing vaccine. Measles vaccine is also given below the age of one year in many lower income countries.
  • Doses of measles-containing vaccine given below the age of one should be discounted and two further doses of MMR vaccine given to ensure adequate protection against both measles and rubella.
  • Current country-specific schedules are available on the WHO website.
  • Children coming to the UK may have received a fourth dose of a diphtheria/tetanus/pertussis-containing vaccine that is given at around 18 months in many countries.
  • Booster doses given before three years of age should be discounted, as they may not provide continued satisfactory protection until the time of the teenage booster. The routine pre-school and subsequent boosters should be given according to the UK schedule.
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full guideline available from…


Public Health England. UK immunisation schedule: the green book, chapter 11. April 2019.
Contains public sector information licensed under the Open Government Licence v3.0.

First included: May 2019. 

PHE UK immunisation schedule (Green Book chapter 11)