Vaccinations are a highly effective method of preventing certain diseases. Vaccinations in travellers are one of the safest methods to avoid a range of dangerous infections that may be encountered abroad. Most seafarers will have received childhood vaccinations through routine immunization programs in their home countries. However, seafarers rarely carry evidence of childhood vaccines with them and often are not aware of routine vaccines they received. If no documentation is available on previous vaccinations, persons must be considered non-immune and vaccinations provided during pre-travel consultation.
Employers may require certain vaccinations as a prerequisite for employment. In the shipping industry there is traditionally a strict observance of vaccinations that are mandatory or believed to be mandatory for entry to countries, such as a Yellow Fever (mandatory for international travel in certain areas by WHO´s International Health Regulations 2005), Cholera or Meningococcal Disease (currently or formerly required by some national governments). On the other hand, other vaccines for specific occupational risks such as hepatitis A, chickenpox, measles or influenza are neglected.
The medical doctor who performs a pre-employment exam will need to assess
- the specific medical risks of the area where the ship is sailing,
- national and international recommendations and requirements
- the company’s policy regarding vaccinations
- specific occupational risks
- individual risks
- hygienic and medical conditions on board
- available documentation on previous vaccinations
It is necessary to consult the seafarer on follow-up injections to gain full immunity. Furthermore the medical doctor needs to advise the seafarer about risks in the period before the vaccine will become fully effective.
The medical doctor must be aware of the complexity of the issue in the maritime environment. It is the medical doctor’s obligation to inform the seafarer on benefits and risks of the vaccination (preferably by written and oral information in the seafarers native language, alternatively in English). However, the area of operation of the company and the degree of flexibility the ship’s management requires in terms of crewing and routes must be considered. Given the overall excellent safety profile of vaccines, the medical doctor will be able to recommend a vaccination in most cases if individual risks (contraindications) are clearly ruled out.
Generally speaking, the recommendations for immunisation and prophylaxis will depend on the occupational infection risks and on national and international immunization requirements which mainly focus on the prevention of the spread of the disease.
Infection risks in a seafarer will depend on
- the individual immunity of a seafarer (against diseases such as hepatitis A, measles or chickenpox by natural immunity or childhood immunization)
- the ports visited (such as areas of risk for yellow fever infection or where the mosquito vector is present)
- duties undertaken (such as maintenance of sewage systems, providing medical care)
- living conditions on board (such as single or multiple accommodation)
- the “mix” of persons onboard
(mix of persons from high and low endemicity areas for certain diseases or contact with a large number of persons on board passenger ships including children and elderly persons)
- the availability of medical and hygienic preventative measures
- treatment availability in case of an influenza outbreak, availability of disinfection
- extent of travel away from ship (such as travel in rural areas, e.g. for rabies, risk)
A reliable source of information in the global environment of shipping is WHO´s Book “International Travel and Health” and the US Centers for Disease Control “Yellow Book” that are updated yearly:
Based on the traveller’s individual risk assessment, a health care professional can determine the need for immunization. The medical doctor advising the seafarers and their employer may evaluate the immunization requirements in an individual seafarer using the following categories:
- Routine childhood immunizations to be recommended in all seafarers (e.g. measles, mumps, hepatitis B).
- Routine immunizations for adults to be recommended to all seafarers (e.g. tetanus, diphtheria).
- Mandatory immunizations that may be required for travel to certain areas (Yellow Fever)
- Additional immunizations to be recommended depending on occupational risks and travel to disease-endemic areas (e.g. hepatitis A, rabies).
There is no immunization for Malaria infection as of now. However preventative Chemotherapy is available and described in detail in the above named sources of WHO and CDC. Advice on malaria prophylaxis can often usefully be given at the same time as vaccinations are administered.
Documentation of the immunization the “Model International Certificate of Vaccination or Prophylaxis” as given in Annex 6 of the International Health Regulations 2005 is to be used. It is mandatory to clearly display
- the brand name of the vaccine, the manufacturer and batch no.
(you may use the sticker from the vial)
-mode of administration (oral, IM, s.c.)
- print name and address (stamp) of clinician, signature.
- for yellow fever vaccination: official seal