Immunization Differences between the U.S. and Japan

It is noteworthy to the physicians and Japanese travelers to the United States that there are certain differences between the U.S. and Japan in the scheduling and frequency of Immunization. In general, immunization in the United States is more involved than most countries, simply due to availability of the new vaccines. Also, the high risk that many immigrants impose by transferring diseases that are still prevalent in developing countries, such as Diphtheria, require a more aggressive approach to prevention of these illnesses.

The following is a brief explanation of the different types of immunizations available and ones that are required. This information has been adopted from ACIP, AAP, and AAFP. The purpose of this bulletin is to provide information and it is not intended to substitute a physician consultation.

DTaP or DTP: This is a combination vaccine composed of Diphtheria, Tetanus, and Pertussis or Whooping Cough. All three of these diseases are still quite prevalent in the United States and children are at risk of exposure. The new type of this vaccine is the acellular type, which has been introduced in the past year and is meant to decrease the likelihood of the febrile illness that usually follows the "whole cell killed Pertussis" organism. Children older than 7 should receive only a modified form of the Tetanus vaccine.

Polio: Polio which in the old days used to claim many lives due to paralysis and eventual respiratory failure, now is overcome by the Polio vaccine. This is an attenuated vacome. In other words, it is made of weakened Polio virus. This vaccine comes in two forms. The injectable type which offers humoral immunity but no gut immunity. The second form or the old type is oral and has rarely been associated with Polio like syndrome. To prevent such a problem, it is recommended that children receive a total of 4 doses; the first two injectable, and the last two oral.

Varicella: This immunization is meant to eliminate the occurrence of chickenpox in children. Although chickenpox is conceived as a benign childhood disease, a significant number of previously healthy children require hospitalization or ICU care per year. The complications or sequelae of this disease include Varicella pneumonia, encephalopathy, and secondary streptococcal infection. Therefore, this vaccination as a single dose before the age of 12 and two doses after the age 13 is offered to those who may be interested in this means of prevention. Do not give this vaccine to children less than 12 months of age.

MMR: This is also a combination vaccine, which is given separately in Japan. MMR includes Measles, Mumps, and Rubella vaccine. In the County of Los Angeles, all children entering high school are required to acquire two doses.

Hib: This is a vaccine that in the recent years has made a tremendous impact on the preventive care of the children. Hemophilus influenza which is responsible for such diseases as meningitis and tracheitis is seen far less frequently now than a few years ago. All children under 15 months of age are encouraged to be immunized against this organism.

Hep-B: In Los Angeles County, all children entering school are required to start a series of three immunizations against the Hepatitis B virus that is associated with a great deal of morbidity and mortality. Since prevention is the most effective means of Hepatitis infection control, we encourage all travelers to take advantage of this vaccine that is not yet routinely administered in Japan and Europe. This is particularly important to the Japanese, since there is a high prevalence of Hepatitis B in Asia.