G.9 Vaccinations in Maritime Medicine

Details

G.9.1 Introduction

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 the routine vaccines they received. If no documentation is available on previous vaccinations, seafarers must be considered non-immune and vaccinations provided during pre-employment 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 Corona Virus Vaccination,  Yellow Fever, mandatory for international travel in certain areas as per the International Health Regulations 2005, Cholera, Polio or Meningococcal Disease that are currently or formerly required by some national governments. On the other hand,  vaccines for specific occupational risks such as Hepatitis A, Chickenpox, Measles or Influenza are neglected.

Before vaccination the seafarer should be advised on:

  • the need for follow-up injections to gain full immunity
  • risks in the period before the vaccine becomes fully effective.
  • benefits and risks of the vaccination, preferably both verbally and in writing in the seafarers native language or alternatively in English.
  • the ship’s management company requirements for vaccination .

Given the overall excellent safety profile of vaccines, the doctor will be able to recommend a vaccination in most cases if individual contraindications are clearly ruled out.

G.9.2 Vaccination Requirements

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.

When considering the vaccination requirement of an individual seafarer many factors should be considered, including but not limited to:

  • the individual immunity of a seafarer against diseases such as Hepatitis A, measles or chickenpox by natural immunity or childhood immunization
  • the operational area of the company and ports to be visited such as areas of risk for yellow fever infection or where the mosquito vector is present and other medical risks in the area
  • national and international recommendations and requirements
  • specific occupational risks in the duties undertaken such as maintenance of sewage systems, providing medical care
  • living conditions on board such as single or multiple accommodation
  • the likely “mix” of persons onboard, that is the potential mix of persons from high and low endemicity areas for certain diseases or contact with a large number of vulnerable persons on board passenger ships including children and elderly persons
  • treatment availability in case of an outbreak of disease, for example, influenza and the availability of disinfection etc
  • individual risk factors such as behaviour and the extent of travel away from ship (such as travel in rural areas, e.g. for rabies, risk)
  • the availability of medical and hygienic preventative measures and general condition on board
  • the company’s policy regarding vaccinations

A reliable source of information in the global environment of shipping is the WHO´s Book “International Travel and Health” and the US Centers for Disease Control “Yellow Book” that are updated yearly http://www.who.int/ith/en/  and http://wwwnc.cdc.gov/travel/page/yellowbook-home-2014

G.9.3 Vaccination Recommendations

Based on the individual risk assessment, a health care professional can determine the need for immunisation. The recommendations are usually made in the following categories:

  • Routine childhood immunisations to be recommended in all seafarers, for example, measles, mumps, Hepatitis B, chickenpox.
  • Routine immunisations for adults to be recommended to all seafarers for example tetanus, diphtheria.
  • Mandatory immunisations that may be required for travel to certain areas, for example, Yellow Fever or Corona-Virus Vaccination
  • Additional immunisations to be recommended depending on occupational risks and travel to disease-endemic areas, for example, Hepatitis A, rabies.

There is currently no vaccine for Malaria infection but preventative chemotherapy is available and described in detail in the above named sources from the WHO and CDC. Advice on malaria prophylaxis can often usefully be given at the same time as vaccinations are administered.

Documentation of immunisation(s) should use the “Model International Certificate of Vaccination or Prophylaxis” as given in Annex 6 of the International Health Regulations 2005. It is mandatory to clearly display:

  • date
  • the brand name of the vaccine, the manufacturer and batch no, you may use the sticker from the vial
  • dose
  • mode of administration, for example, oral, IM, s.c
  • print name and address (stamp) of clinician and signature.
  • for yellow fever vaccination: official seal