Meningococcal vaccine is recommended for all travelers to the Mountain and Benguet provinces, especially if prolonged contact with the populace is likely (see "Recent outbreaks" below). Meningococcal vaccine has few side-effects. Mild redness at the injection site may occur. Young children may develop transient fever.
Hepatitis A vaccine is recommended for all travelers over one year of age. It should be given at least two weeks (preferably four weeks or more) before departure. A booster should be given 6-12 months later to confer long-term immunity. Two vaccines are currently available in the United States: VAQTA (Merck and Co., Inc.) (PDF) and Havrix (GlaxoSmithKline) (PDF). Both are well-tolerated. Side-effects, which are generally mild, may include soreness at the injection site, headache, and malaise.
Travelers who are less than one year of age, are pregnant, or have less than two weeks before departure should receive a single intramuscular dose of gammaglobulin (see hepatitis A for dosage) instead of vaccine.
Typhoid vaccine is recommended for all travelers. It is generally given in an oral form (Vivotif Berna) consisting of four capsules taken on alternate days until completed. The capsules should be kept refrigerated and taken with cool liquid. Side-effects are uncommon and may include abdominal discomfort, nausea, rash or hives. The alternative is an injectable polysaccharide vaccine (Typhim Vi; Aventis Pasteur Inc.) (PDF), given as a single dose. Adverse reactions, which are uncommon, may include discomfort at the injection site, fever and headache. The oral vaccine is approved for travelers at least six years old, whereas the injectable vaccine is approved for those over age two. There are no data concerning the safety of typhoid vaccine during pregnancy. The injectable vaccine (Typhim Vi) is probably preferable to the oral vaccine in pregnant and immunocompromised travelers.
Japanese encephalitis vaccine is recommended only for long-term (1 month) travelers to rural areas or travelers who may engage in extensive unprotected outdoor activities in rural areas, especially in the evening, during shorter trips. Japanese encephalitis is transmitted by mosquito bites and is thought to occur on all islands. Outbreaks have been reported in Nueva Ecija, Luzon, and Manila. The vaccine (JE-VAX; Aventis Pasteur Inc.) (PDF) is given as a series of three injections on days 0, 7 and 30. If time is short, the third dose may be given on day 14. Mild side effects including fever, headache, muscle aches, malaise and soreness at the injection site occur in about 20% of those vaccinated. Serious allergic reactions including urticaria, angioedema, respiratory distress and anaphylaxis occur in approximately 0.6% of vaccinees and may occur as long as one week after vaccination. Any person who receives the vaccine should be observed in the doctor's office for at least 30 minutes following the injection and should complete the full series at least 10 days before departure. There are no data concerning the safety of Japanese encephalitis vaccine during pregnancy. In addition to vaccination, strict attention to insect protection measures is essential for anyone at risk.
Hepatitis B vaccine is recommended for travelers who will have intimate contact with local residents or potentially need blood transfusions or injections while abroad, especially if visiting for more than six months. It is also recommended for all health care personnel. Two vaccines are currently licensed in the United States: Recombivax HB (Merck and Co., Inc.) (PDF) and Engerix-B (GlaxoSmithKline) (PDF). A full series consists of three intramuscular doses given at 0, 1 and 6 months. Engerix-B is also approved for administration at 0, 1, 2, and 12 months, which may be appropriate for travelers departing in less than 6 months. Side-effects are generally mild and may include discomfort at the injection site and low-grade fever. Severe allergic reactions (anaphylaxis) occur rarely.
Rabies vaccine is recommended for those at high risk for animal bites, such as veterinarians and animal handlers, and for long-term travelers who may have contact with animals and may not have access to medical care. In May 2001, a man died of rabies in a London hospital after being bitten during a dog fight in the Philippines. See Eurosurveillance for details. In the Philippines, most cases result from dog bites, though bites from monkeys and other wildlife may also be responsible. The risk of rabies is particularly high in the Bicol region (see ProMED-mail). A complete preexposure series consists of three doses of vaccine injected into the deltoid muscle on days 0, 7, and 21 or 28. Side-effects may include pain at the injection site, headache, nausea, abdominal pain, muscle aches, dizziness, or allergic reactions.
Any animal bite or scratch should be thoroughly cleaned with large amounts of soap and water and local health authorities should be contacted immediately for possible post-exposure treatment, whether or not the person has been immunized against rabies.
All travelers should be up-to-date on routine immunizations, including
Tetanus-diphtheria vaccine (recommended for all travelers who have not received a tetanus-diphtheria immunization within the last 10 years.)
Measles vaccine (recommended for any traveler born after 1956 who does not have either a history of two documented measles immunizations or a blood test showing immunity. Many adults who had only one vaccination show immunity when tested and do not need the second vaccination. Measles vaccine should not be given to pregnant or severely immunocompromised individuals.)
Varicella (chickenpox) vaccine (recommended for any international traveler over one year of age who does not have either a history of documented chickenpox or a blood test showing immunity. Many people who believe they never had chickenpox show immunity when tested and do not need the vaccine. Varicella vaccine should not be given to pregnant or immunocompromised individuals.)
Cholera vaccine is not generally recommended, even though cholera occurs in the Philippines, because most travelers are at low risk for infection. The only cholera vaccine approved for use in the United States has low efficacy and a high incidence of adverse reactions, and is no longer being manufactured or sold. Two oral vaccines have recently been developed but are not yet approved in the United States (see cholera). These vaccines, where available, may be considered for certain high-risk individuals, such as relief workers or health professionals.
An outbreak was reported from the Paco and San Andres areas of Manila in September 1996.
Polio immunization is recommended. Between March and July, 2001, three cases of poliomyelitis were reported from the Philippines. See the Centers for Disease Control for details. Any adult who received the recommended childhood immunizations but never received a booster as an adult should be given a single dose of inactivated polio vaccine. All children should be up-to-date in their polio immunizations and any adult who never completed the initial series of immunizations should do so before departure. Side-effects are uncommon and may include pain at the injection site. Since inactivated polio vaccine includes trace amounts of streptomycin, neomycin and polymyxin B, individuals allergic to these antibiotics should not receive the vaccine.
Yellow fever vaccine is required for all travelers over one year of age arriving from a yellow-fever-infected country in Africa or the Americas, but is not recommended or required otherwise. Yellow fever vaccine (YF-VAX; Aventis Pasteur Inc.) (PDF) must be administered at an approved yellow fever vaccination center, which will give each vaccinee a fully validated International Certificate of Vaccination. Yellow fever vaccine should not in general be given to those who are younger than nine months of age, pregnant, immunocompromised, or allergic to eggs. It should also not be given to those with a history of thymus disease or thymectomy.
