Polio vaccination for stays in countries with polio outbreaks
The World Health Organization (WHO) is still reporting an increase in cases of polio (poliomyelitis) in several countries. The Norwegian Institute of Public Health recommends vaccination before travelling to countries with outbreaks to protect against infection and to avoid further spread of the virus.
As of May 2018, the recommendations apply to the following countries: Pakistan, Afghanistan, Nigeria, Somalia, Kenya, Syria, DR Congo, Cameroon, Niger, Chad and Central African Republic.
Vaccine advice with travel and longer stays in countries with polio outbreaks
WHO requires countries with a high risk of export of the polio virus to offer vaccination to everyone travelling from these countries. This applies to Afghanistan, Pakistan, Nigeria and Somalia (May 2018). This comes in addition to intensification of polio vaccination to the population. To prevent the export of infection from these countries, vaccination must be given 4 weeks and 12 months before leaving these countries. This must be documented with an international vaccine certificate.
The vaccination advice applies to people of all ages. Children must also have been vaccinated during the 12 months before departure from these countries, even though the Norwegian immunisation programme considers them to be fully vaccinated. When infants are going to travel to the above countries, the public health clinic may consider earlier vaccination, and may consider the 4-dose programme for infants who will not have time to get two doses of polio vaccine before departure. The polio vaccine is administered at vaccination clinics, public health clinics or by a general practitioner.
Syria and DR Congo also have polio outbreaks, but these are of a milder type (vaccine-derived polio virus). Recently, such viruses have also been found in environmental samples in Kenya. WHO and Norwegian health authorities recommend that people travelling from these countries should follow the same advice.
Cameroon, Niger, Chad and the Central African Republic are considered to be vulnerable to polio outbreaks, even though they have not yet reported any polio cases. When travelling to these countries, it is important to ensure updated polio vaccination.
About polio and polio vaccine
Polio (poliomyelitis) is a viral disease caused by three known types of polio virus: types 1, 2 and 3. It can be eradicated by a vaccine because it is only found in humans.
Over 90 % of those infected have no symptoms but excrete the virus in faeces. 9 per cent have vague, influenza-like symptoms, while less than 1 per cent develop paralysis. The paralysis can affect muscles anywhere in the body but most often in the legs or arms. If the diaphragm muscles are affected, severe breathing difficulties and even death may occur. The last major polio epidemic in Norway took place in the mid-1950s.
The use of polio vaccine has led control of the disease in most places in the world, and the WHO European Region was declared polio-free in 2002. Polio virus exists today only in Afghanistan, Pakistan and Nigeria, and in 2017 there were fewer cases than ever before.
There are two types of polio vaccine, one inactivated (IPV - used in Norway) and a live, weakened oral vaccine (OPV) used in many countries. Polio disease caused by vaccine can only occur with the use of the live, weakened oral vaccine. In a population with low immunity, vaccine virus may begin to circulate and, in a few cases, gradually reclaim the ability to elicit polio with paralysis (circulating vaccine-induced polio virus (cVDPV)). In May 2018, vaccine-derived polio virus is circulating in Somalia, Kenya, DR Congo and Syria.