No 27a+b - 2014

Recommended vaccinations for foreign travel

As in previous years, Statens Serum Institut and a reference group appointed by the specialist societies have revised the country-specific recommendations for prevention of infectious diseases in connection with travels abroad.

Recommended vaccinations for foreign travel, EPI-NEWS 27b, 2014

Changes for malaria prophylaxis were described in EPI-NEWS 26/14. For the diseases that are preventable through vaccination, the following changes apply:

Polio

The WHO has declared the international spread of polio a public health emergency of international concern and has issued recommendations for 10 countries where polio currently occurs. The countries are as follows: Afghanistan, Cameroon, Ethiopia, Equatorial Guinea, Iraq, Israel, Nigeria, Pakistan, Somalia and Syria. In 2013, poliovirus was found in wastewater in Israel, but no-one in Israel has developed paralytic polio, EPI-NEWS 38/13. Over the past year, the remaining nine countries have reported cases of paralytic polio.

The WHO has divided the ten countries affected by polio into two groups:

Four countries currently exporting polio: Pakistan, Cameroon, Syria and Equatorial Guinea, from where polio cases have been reported, and from where poliovirus has recently spread to other countries.

Six polio-affected countries: Afghanistan, Ethiopia, Iraq, Israel, Somalia and Nigeria, where wild poliovirus has been found, but from where wild poliovirus is currently not spreading to other countries.

The new WHO recommendations are temporary and apply to anyone visiting or residing in the countries where polio has been observed. The objective of the recommendations is to prevent poliovirus from spreading with travellers from countries where polio has been observed to countries which have been declared polio-free. It has been demonstrated that poliovirus can infect fully IPV-vaccinated persons without producing symptoms and that the virus can then excrete from the intestine over a period of time.

The risk of carrying poliovirus in the intestine is lower in persons who have received a polio booster vaccination with either OPV or IPV. After vaccination, the risk again slowly increases with time. Therefore, the WHO recommends that residents of and visitors to the countries where polio has been observed receive an extra dose of polio vaccine within 12 months before leaving one of these countries.

The WHO recommends that the four countries from where wild poliovirus is currently spreading (Pakistan, Cameroon, Syria and Equatorial Guinea) ensure that:

• residents and long-term visitors (i.e. > 4 weeks) receive a dose of oral polio vaccine (OPV) or inactivated poliovirus vaccine (IPV) between 4 weeks and 12 months prior to international travel activity 
   
• those undertaking urgent travel (i.e. within 4 weeks) and who have not received a dose of OPV or IPV in the previous 4 weeks to 12 months receive a dose of polio vaccine at least by the time of departure 
   
• such travellers are provided with an international certificate of vaccination where their polio vaccination is recorded, and this certificate will then serve to document that they have been vaccinated.

Furthermore, the WHO also recommends that the seven countries in which wild poliovirus has been detected, but from where the virus is currently not spreading, encourage their citizens to follow the same vaccination guidelines as those that apply to the countries from which spreading has been observed.

As from 1 June 2014, Pakistan has implemented the WHO's recommendation and introduced a requirement that anyone leaving the country present their international vaccination certificate documenting that they have received polio vaccination, as described above. There is currently no knowledge as to how many of the remaining countries have also implemented the recommendation.

In the EU, the Commission's Health Security Commission is considering to offer its citizens a polio vaccination (booster) prior to travel to the three polio-exporting countries. This recommendation is motived by the EU countries' need to ensure that their citizens do not enter a country which they will later not be able to leave, e.g. due to a lacking vaccine or lack of funds to have a vaccination, and to ensure that the vaccines provided are quality-assured and administered using sterile syringes.

On this basis and until further notice, it is therefore recommended that Danish travellers who will be staying in Pakistan, Syria, Cameroon and Equatorial Guinea for more than four weeks receive an IPV booster vaccine if they received their latest polio booster more than 12 months ago. If possible, the vaccinations should be given four weeks before departing, and in any case before departing on the travel. If a traveller has not received the full primary polio vaccination in the form of three doses administered at a minimum interval of 1 month between the first and the second dose, and a minimum of 6 months between the second and the third dose, the full primary vaccination should be completed to ensure protection of the traveller.

According to the WHO, Iraq introduced a requirement for oral polio vaccination for all travellers entering the country as early as in 2013. OPV is not available in Denmark and has not been used in the childhood vaccination programme since 2003. It is recommended that travellers carry their vaccination card with them when travelling so that they may document any previous polio vaccinations. The GP can administer an IPV booster and, if needed, issue a statement doccumenting that the OPV was given as part of the childhood vaccination programme in the 1961-2003 period, but was phased out as part of the global polio eradication campaign. Children born after 1 July 2001 have not been offered OPV but have instead been offered a 4-dose IPV programme, which is considered equivalent.

Finally, in 2014 India has introduced a requirement for oral polio vaccination (OPV) a minimum of four weeks prior to entering the country for any traveller residing in Afghanistan, Nigeria, Pakistan, Ethiopia, Kenya, Somalia or Syria.

Yellow fever

In May 2013, the WHO declared that the protection provided by one yellow fewer vaccination is now considered to be life-long, and that the previous recommendation to have a booster vaccination every 10 years was therefore discontinued, EPI-NEWS 26a/13. The WHO has now declared that by June 2016 at the latest, all countries are expected to have adopted this recommendation, and that from that time, countries cannot require proof of a booster vaccination from previously yellow fever-vaccinated travellers entering their countries. As it is unclear which countries have presently adopted the WHO amendment, it is recommended that travellers going to areas where a yellow fever-vaccination requirement may be in place, including after transit stays in a yellow fever-endemic area, have been vaccinated against yellow fever within the past 10 years and bring documentation to this effect, unless there is specific knowledge that their country of destination no longer requires such measures. It is essential that the international vaccination certificate has been completed thoroughly and correctly. As previously, the vaccination certificate states that vaccination is valid as from ten days after the injection has been received. The duration of the vaccination should be listed as "life-long".

Specific country amendments for yellow fever vaccination:

The following country has discontinued its requirement for vaccination of all travellers: Ghana.

The following countries have introduced a vaccination requirement for travellers entering via a yellow fever-endemic area: French Polynesia, Ghana, Paraguay, Saint Barthelemy, Saint Martin and Wallis and Futuna.

The following countries have discontinued their vaccination requirement for travellers entering via a yellow fever-endemic area: Haiti, Nicaragua, Panama, Syria and Uruguay.

Finally, a number of countries have changed their yellow fever vaccination requirements relating to transit stays in a yellow fever-endemic area. A link to an updated list of these changes is available (in Danish) at SSI's website section on Rejser og smitsomme sygdomme (Travels and infectious diseases) and at the WHO website (footnote 3).

Meningococcal meningitis

According to the WHO, Gambia has introduced a requirement for meningitis vaccination. It has not been specified which vaccine should be used, and it is therefore recommend using a four-valent vaccine that protects against serogroups A, C, Y and W135 and to bring the international vaccination certificate to document that the vaccination has been received (the certificate should be brought anyway, as yellow fever-vaccination is recommended for all travellers going to Gambia).

Japanese encephalitis (JE)

Japanese encephalitis is only found in South-East Asia and the risk area has traditionally been divided into a northern zone with seasonal transmission during the rainy season and a southern zone with all-year transmission. For the countries of the northern zone, the list of countries in EPI-NEWS 27b/14 holds numbers corresponding to the first as well as the last risk month. It is important to underline that this period is indicative only and that it may vary depending on the rainy season. The temperate northern parts of the JE risk area are characterised by considerable annual variation and transmission in the summer half-year. In the remaining countries marked with annual variation (Cambodia, Laos, Thailand and Vietnam), the risk persists throughout the year, but it is greater in the stated periods.

The JE vaccination recommendation for stays lasting four weeks or more in the transmission zone during the risk period is merely instructive. Stays in rural areas with pig farming and wading birds are associated with an increased risk. Stays in urban areas will normally carry only a limited risk. In case of intense exposure or knowledge of ongoing outbreaks, stays shorter than four weeks may justify vaccination. Examples of intense exposure include prolonged stays outdoor in rural areas, particularly in the evening and night, and outdoor activities such as camping, hiking and trekking. Primary mosquito bite prevention should always be recommended. Ongoing outbreaks, risk areas and any seasonal variation are presented (in Danish) at www.ssi.dk/rejser.

Measles

Measles still circulate in a range of countries both in Europe and in other parts of the world, and major outbreaks are observed. Non-immune travellers are at risk of infection and may subsequently introduce the virus to Denmark, EPI-NEWS 12/14; and all travellers above 12 months of age should have received vaccination against measles in the form of MMR vaccination. In connection with measles outbreaks, the vaccine can be used as from 9 months of age, but the vaccination then needs to be repeated after 12 months of age. Under the childhood vaccination programme, two MMR vaccinations are given, when the child is 15 months and 4 years old. It is recommended that all non-immune adults aged 18 years and above receive a single MMR vaccination. Adults are required to pay for the vaccination themselves, but vaccination is free of charge for non-immune women of child-bearing age.

The WHO informs that Paraguay has introduced a requirement for MR vaccination covering anyone entering the country. In Denmark, only the MMR vaccine is available.

Hepatitis A and B

Many travellers have received vaccines against hepatitis A or/and B, but have exceeded the recommend interval between the vaccinations.

For healthy and immuno-competent travellers who are recommended hepatitis B vaccination, please note that: where three hepatitis B vaccinations were given and the minimum intervals were observed, there is no need for any further vaccination, even if the recommended vaccination intervals were exceeded. Booster vaccination is not recommended.

For healthy and immuno-competent travellers who are recommended hepatitis A vaccination, please note that: where two hepatitis A vaccinations were given and the minimum interval was observed, there is no need for any further vaccination, even if the recommended vaccination interval was exceeded. Thus, the vaccination series should never be re-initiated.

The above also applies to combination vaccines covering hepatitis A and B.
(C.S. Larsen, Danish Society of Travel Medicine, S. Thybo, Danish Society for Infectious Disease, J. Kurtzhals, Danish Society for Clinical Microbiology, N.E. Møller, Danish College of General Practitioners, L.S. Vestergaard, Danish Society for Tropical Medicine and International Health, K. Gade, The Danish Paediatric Society, P. H. Andersen, A. H. Christiansen, Department of infectious Disease Epidemiology)

Link to previous issues of EPI-NEWS

2 July 2014