Vaccination

 (This information is not intended to be a substitute for the advice of a doctor or a recommendation for any particular treatment plan. Like any printed material, it may become out of date over time. It is important that you rely on the advice of a doctor for your specific condition.)

 

Seafarer / offshore crew should be vaccinated according to the requirements indicated in the WHO publication “International Travel and Health: Vaccination Requirements and Advice” which is updated periodically.

 1.      Country related risks:

a.    Yellow fever is covered by International Regulations. Vaccination is carried out for two different reasons: (1) to protect the seafarers in Sub-Saharan Africa or Central and South America (between 15º southern - 15º northern latitude) where there is a risk of yellow fever infection; and (2) to protect vulnerable countries from importation of the virus, where the mosquito vectors and potential non-human primate hosts are present. It should be noted that the mosquito vectors of yellow fever bite mostly during daylight hours. The vaccination is effective after 10 days and gives protection for 10 years. Because this vaccine contains live attenuated virus, it should be used cautiously and administered via S.C. injection.

b. There are two kinds of meningococcal vaccine: meningococcal conjugate vaccine and meningococcal polysaccharide vaccine. Both vaccines can protect against meningococcal disease caused by sero-groups A, C, Y, and W-135. Approximately 7–10 days are required after vaccination for development of protective antibody levels. It is highly effective in preventing meningococcal disease caused by these serogroups in about 90% of susceptible adults. Only a single 0.5-mL IM dose is required, and the immunity is believed to be long-lived. Seafarer / offshore crew should be considered for meningococcal immunization only if they are working to areas where meningococcal disease is known to be highly endemic or epidemic, such as Saudi Arabia and Sub-Saharan meningitis belt - from West to East: Gambia, Senegal, Mali, Burkina Faso, Ghana, Niger, Nigeria, Cameroon, Chad, Central African Republic, Sudan, South Sudan, Uganda, Kenya, Ethiopia, Eritrea.  (Serogroup A). Peoples who were vaccinated previously and are living in or returning to the meningitis belt may need to be revaccinated, if it has been >5 years since their last meningococcal vaccine. In local epidemics or household cases, prophylaxis with rifampin (600 mg q 12 h for four doses) may be given to those intimately exposed.

c.   Malaria is a particular risk in tropical and subtropical regions. Time from mosquitoes bite to symptoms is 8-10 days. No vaccine is available. A course of chemoprophylaxis is mandatory, such as 250 mg Atovaquone + 100 mg Proguanil (MalaroneTM) one tablet daily starting one day before travel to endemic area and continue for seven days after leaving malarious area, or Doxycycline one tablet (100 mg) daily starting one day before travel to endemic area and continue for four weeks after leaving malarious area, or Chloroquine base 300 mg (chloroquine phosphate 500 mg) every week, starting one week before travel to endemic area and continue for one week after leaving malarious area.

 2.      Job related risks:

a.      Seafarers whose work involves maintaining of sewage system are at risk of fecal contamination. Immunization against Typhoid and Hepatitis A are highly recommended.

·         There are two types of typhoid vaccines:

o  Injectable Vi CPS. Capsular Vi polysaccharide vaccine (Vi CPS), containing 25 μg of polysaccharide per dose (0.5 ml), is given I.M. in a single dose and produces protection 7 days after injection. In endemic areas, the protective efficacy is 72% after 1.5 years and 50% after 3 years. Booster is needed every 2 years.

o   Oral Ty21a is live-attenuated mutant strain of Salmonella typhi Ty21a, supplied as enteric coated capsules, given orally in three doses (four in North America) 2 days apart (on alternate days), and produces protection 7 days after the final dose. Seven years after the final dose the protective efficacy is 67% in residents of endemic areas but may be less for travelers. Proguanil, mefloquine and antibiotics should be stopped from 3 days before until 3 days after giving Ty21a. Booster is needed every 5 years.

·      Current hepatitis A vaccines, all of which based on inactivated (killed) virus, are safe and highly effective, given I.M.  Anti-HAV antibodies are detectable by 2 weeks after administration of the first dose of vaccine. The second dose – given at least 6 months and usually 6–24 months, after the first dose – is necessary to promote long-term protection. Anti-HAV antibodies probably persist for 25 years or more. Booster dose is not recommended.

b.   Food handlers will, if infected, pose a risk of transmitting food-borne infections to other crews and passengers. They too should have Typhoid and Hepatitis A immunization.

c.  Deck and engine crews are at risk of wounded, so immunization with Tetanus Toxoid is highly recommended. The Tetanus Toxoid 0.5 ml I.M. 3 doses at 4 weeks intervals give protection for 10 years.

d.  At present every cruise-liners have their own vaccination policy for their crewmembers. Outbreaks of Measles, Rubella, Varicella, Meningococcal meningitis, Hepatitis A, Legionellosis, and respiratory and gastro-intestinal illnesses among ship travelers have been reported. In recent years, influenza and norovirus outbreaks have been public health challenges for the cruise industry.

·        There are two types of Flu vaccines:

o   The "flu shot"— an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm, 0.5 ml single dose annually.

o    The nasal-spray flu vaccine — a vaccine made with live, weakened flu viruses that do not cause the flu, sometimes called LAIV for “live attenuated influenza vaccine”.

This seasonal influenza vaccine does neither provide protection against avian influenza H5N1, H7N9 nor swine influenza H1N1 viruses; but since 2010 the seasonal influenza vaccine includes the swine influenza H1N1 strain.

·        The MMR vaccine is a mixture of three live attenuated viruses, administered 0.5 ml S.C. single dose for immunization against measles, mumps and rubella.

·        The Varicella (Chickenpox) vaccine should be given two doses at least 28 days apart.

 3.      Sexual related risks:

Hepatitis B and Human Papilloma are the only sexual transmittable diseases that have its vaccines.

a.  Hepatitis B vaccine is a recombinant vaccine, should be delivered through a series of three IM injections in the upper arm or thigh over a six-month period. The second and third doses should be given two and six months after the first dose, give protection for 10 years. An alternative is very rapid schedule of administration of hepatitis B vaccine: day 0; 7 and 21, an additional dose is given at 12 months.

b.   Since 2006, two HPV vaccines have been licensed; one vaccine targeting four and the other two HPV genotypes. Both vaccines are designed to protect against about 70% of cervical cancer cases worldwide (the 4-valent vaccine also protects against genital warts). HPV Vaccine is also a recombinant vaccine, IM injections, in three doses. The second and third doses should be given two and six months after the first dose. The protective effects of the vaccine are expected to last a minimum of 4.5 years after the initial vaccination

 

(Source: WHO, U.S. Centers for Disease Control and Prevention, UK-Maritime and Coastguard Agency: Prevention of Infectious Disease at Sea by Immunisations and Anti-Malaria Medication (prophylaxis) & Danish Maritime Authority: Vaccination and other kinds of Prevention for Seafarers)