Mark D. Gershman, Emily S. Jentes, Rhett J. Stoney (Yellow Fever), Kathrine R. Tan, Paul M. Arguin (Malaria)
The following pages present country-specific information on yellow fever (YF) vaccine requirements and recommendations (see Table 3-27) and malaria transmission information and prophylaxis recommendations. Country-specific maps of malaria transmission areas, country-specific maps depicting yellow fever vaccine recommendations, and a reference map of China are included to aid in interpreting the information. The information was accurate at the time of publication; however, this information is subject to change at any time as a result of changes in disease transmission or, in the case of YF, changing country entry requirements. Updated information reflecting changes since publication can be found in the online version of this book (www.cdc.gov/yellowbook) and on the CDC Travelers’ Health website (www.cdc.gov/travel). General recommendations for other vaccines to consider during the pre-travel consultation can be found on the CDC Travelers’ Health website (www.cdc.gov/travel).
YELLOW FEVER
Since publication of the 2018, large YF outbreaks occurred in eastern Brazil in 2017 and 2018, involving states where YF was not previously considered endemic. Notably, human YF cases occurred within the greater metropolitan area of São Paulo City and not far from the metropolitan limits of Rio de Janeiro City. In response, the Brazil Ministry of Health conducted mass vaccination campaigns in the newly affected areas. Based on a review of the situation by the World Health Organization (WHO) Scientific and Technical Advisory Group on Geographical Yellow Fever Risk Mapping, in which CDC participates, preliminary expanded YF vaccination recommendations were made for international travelers to the eastern and southeastern states of Brazil. Given that the Brazil Ministry of Health has initiated its plan to vaccinate the entire population of Brazil against YF by mid-2019, these preliminary vaccination recommendations for international travel will likely be made permanent by the advisory group.
Revaccination against yellow fever was previously required by certain countries at 10-year intervals to comply with International Health Regulations (IHR). In 2014, the World Health Assembly (of WHO) adopted the recommendation to amend the IHR by removing the 10-year booster dose requirement, and stipulated a 2-year transition period for this change. Consequently, as of July 11, 2016, a completed International Certificate of Vaccination or Prophylaxis (ICVP) is valid for the lifetime of the vaccinee. Moreover, countries cannot require proof of revaccination (booster) against yellow fever as a condition of entry, even if the last vaccination was ≥10 years prior.
In the United States, the Advisory Committee on Immunization Practices (ACIP) published a new recommendation in 2015 that 1 dose of yellow fever vaccine provides long-lasting protection and is adequate for most travelers. The recommendation also identifies specific groups of travelers who should receive additional doses and others for whom additional doses may be considered. For details, see the Yellow Fever section earlier in this chapter. For the most up-to-date information about yellow fever vaccine boosters, consult the CDC Travelers’ Health website or the specific publication posted on the ACIP website (www.cdc.gov/mmwr/pdf/wk/mm6423.pdf).
Ultimately, the clinician’s decision whether or not to vaccinate any traveler must take into account the traveler’s risk of being infected with YF virus, country entry requirements, and individual risk factors for serious adverse events after YF vaccination (such as age and immune status). For a thorough discussion of YF and guidance for vaccination, see the Yellow Fever section earlier in this chapter.
NOTE: Despite the recent changes to the IHR regarding YF vaccine boosters, it is uncertain whether all countries with YF vaccination entry requirements will fully adopt this change. Even if countries do modify their official policies to extend the validity period of the ICVP from 10 years to the lifetime of the vaccinee, there is no guarantee that all national border officials will be aware of such policy change or be able to enforce it. CDC obtains information yearly from WHO about official country entry requirements. WHO likely will not be asking countries about YF vaccine booster entry requirements in the yearly questionnaires, because it will be assumed that countries are complying with the amended IHR. This could leave a gap in the foreseeable future in accurate published information about entry requirements for YF vaccine boosters for certain countries. Past experience has demonstrated that information given by consulates and embassies about vaccination requirements is often not accurate. Therefore, providers and travelers should not rely solely on such information when determining current YF vaccination entry requirements for specific destinations. With the caveats described above, readers should refer to the online version of this book (www.cdc.gov/yellowbook) and the CDC Travelers’ Health website (www.cdc.gov/travel) for any reported updates to country entry requirements since publication of this edition.