Getting Ready: Pre-travel Inoculation: Required
Yellow fever is a viral infection which occurs in both tropical Africa and South America. It is transmitted by the culex mosquito. Its main effects are on the liver, and the mortality rate from this infection may be as high as 30%.
Yellow fever vaccine is a requirement for entry to several countries in Africa. As well, it is required to enter certain countries when one has recently travelled in a country which has yellow fever, or lies in the traditional endemic zones for yellow fever.. For example, there is no yellow fever in Thailand, but if one were travelling from Nigeria or Brazil (which have yellow fever) to Thailand, it would be required. In addition, it is a good idea to be vaccinated if one is entering rural areas in the traditional endemic areas.
The vaccine, which is given as a single dose, is virtually 100% effective after 10 days, and provides protection for 10 years. It is a live vaccine, and therefore is not recommended for pregnant women or anyone who is immunosuppressed. However in these situations, one must weigh the risks against the benefits. It can be given to children as young as 6 months of age if they are at significant risk. The side effects are usually mild, and may be delayed until 5 to 10 days after vaccination.
In recent years, there has been some controversy regarding the use of this vaccine. A rare side effect called Yellow Fever Viscerotropic Disease has been reported in more than 20 cases (in the past decade or so). It seems to occur more in the elderly (make that over 60 years of age!). It does not seem to happen in those who have previously received the vaccine, regardless of their age. The fatality rate from this adverse effect, which resembles an actual case of yellow fever, is greater than 50%. So, if you are “elderly”, you might want to question your travel advisor regarding the risks vs. the benefits of this vaccine. Thankfully, the risks of either serious side effects or contracting the infection are exceedingly low.
Yellow fever vaccine is only administered at centres that are specifically designated as Yellow Fever clinics.
Meningococcal disease is caused by a bacterium, which is transmitted from person to person via close contact such as coughing, sneezing or direct contact. It may involve the blood (meningococcemia) or the brain and spinal cord (meningitis). The symptoms may include fever and headache. While it often begins like a mild illness, it may quickly progress to shock or coma. It is usually accompanied by a petechial (like bruises) rash.
The vaccine, which protects against 4 strains of the bacteria – A,C,Y, W-135 - is recommended for travellers to areas where meningococcal disease is prevalent, or where there have been significant outbreaks in the recent past. This applies particularly to longer term travellers who will have close contact with the local population. The “Meningitis Belt” of Africa presents the greatest risk, particularly during the dry, winter months between December and May. As well, because there have been large outbreaks in the past, vaccination is a requirement for religious pilgrims entering Saudi Arabia.
The vaccine consists of one dose, and the side effects are minimal. It provides protection for between 3 - 5 years. A newer preparation of this vaccine called Menactra is more effective than the previous vaccine.