Post-exposure MMR vaccination and exclusion

We recommend prompt vaccination with MMR for all those contacts without acceptable presumptive evidence of immunity. Contacts should be vaccinated promptly with MMR, even if it is greater than 72 hours after the exposure. Further cases of measles may occur if someone is already incubating the disease, but the liberal use of MMR should reduce the likelihood of ongoing transmission.

Acceptable presumptive evidence of immunity is:

  • anyone born before 1 January 1969 
  • documentation of immunity or previous infection
  • for people over four years, documentation of two doses of measles-containing vaccine, given at least one month apart and given after 12 months of age.
  • for children aged between 15 months and 4 years, documentation of one dose of MMR is considered fully vaccinated for age. However, we recommend a second dose of MMR as soon as possible after exposure but no sooner than one month after the first dose.

It is not generally recommended to wait for serology results to determine immunity. The delay in providing post-exposure prophylactic immunisation reduces the likelihood of the treatment working. It is safe to give MMR (or NHIG, as indicated in the measles chapter of the immunisation handbook) to people who are already immune. Therefore, we recommend that contacts without evidence of immunity should be vaccinated promptly.

Exclusion from school or work of contacts having received MMR

Vaccination with MMR post-exposure cannot guarantee protection.

Contacts who have previously received one documented dose of MMR and then receive their second dose of MMR within 72 hours after first exposure can go back to school or work.

Non-immune contacts who have received their first documented MMR vaccination should be excluded for 14 days after their last exposure, unless they subsequently meet the criteria for immunity.

If contacts receive their second MMR more than 72 hours after exposure, they should be excluded for 14 days after the last exposure to a person with measles.

The Medical Officer of Health may decide in limited circumstances not to follow these exclusion recommendation. The Medical Officer of Health may allow a person back to school of work if the first dose of MMR is given within 72 hours of the first exposure, or the second dose of MMR is given greater than 72 hours of the first exposure if:

  • this person will be exclusively returning to a setting where anyone without presumptive evidence of immunity has been excluded, and
  • this person will continue to be monitored for signs and symptoms consistent with measles for at least one incubation period.

If the outbreak is ongoing:

  • Those who have received the second dose of MMR more than 72 hours after exposure may return to school or work if they remain well and more than 14 days have elapsed since their last contact with a case.
  • Those who have received only the first dose of MMR within or more than 72 hours after exposure should receive a second dose of MMR before going to school or work. The second dose of MMR should be given as early as 4 weeks after the first.

Measles exclusion algorithm

Use this flowchart to help decide what to do when a contact is not fully vaccinated.

 

 

 

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