Epidemiology & Disease Mechanism
Treatment of WAS
Coping with WAS
These are the immunization schedules based on age for normal and immunocompromised children and adults.
Vaccination of Immunocompromised adults and adults with asplenia
Patients with WAS can receive all the routine recommended vaccines except for live vaccines which are contraindicated1. The virus that is used in these "live virus vaccines" are "attenuated or weakened' ie. they are not killed but have a reduced power to produce disease in the recipient. When they are given to patients who are immunodeficient, these "attenuated" viruses can cause serious disease. They are therefore contraindicated2. Under certain circumstances, such as for travel, some of these live virus vaccines may be given after consultation with an immunologist who is familiar with the disease. Patients with WAS should not assume that they are protected from the disease because they have received a vaccine. Measuring titers after the vaccine can determine if the vaccine was efficient and if the patient needs booster doses.
The routinely used live vaccines are:
1. MMR (measles, mumps and rubella)
2. Varicella (chicken pox)
3. Flumist Live Attenuated Influenza Vaccine(LAIV) which is the influenza vaccine given as a intra nasal spray
5. Oral polio vaccine (OPV). This vaccine is no longer used in the U.S.
6. Shingles (Herpes Zoster)
7. BCG(Vaccine againt TB-Tuberculosis) This is no longer a routinely used vaccine in the US, but is used under many circumstances. It is still used, especially in countries where TB is prevalent.
Live vaccines that are used in special circumstances such as during travel to a foreign country or during an epidemic are: Oral Typhoid Vaccine and the Yellow Fever Vaccine
Vaccines Recommended for patients with WAS
In addition to the routine vaccines, patients with WAS are recommended to receive the pneumovax and the meningococcal vaccine. These vaccines are important for two reasons. These patients are more susceptible to serious infections with capsulated bacteria such as the Pneumococcs, Meningococcus and Hemophilus and the vaccine can provide significant degree of protection. Secondly, these are patients who might require an emergency splenectomy in the event of a trauma and immunizing them ahead of schedule is advisable.
There are two types of pneumococcal vaccine:
Pneumococcal conjugate vaccine (PCV): Children are routinely offered three injections of PCV at age two months, four months and about 13 months.
Pneumococcal polysaccharide vaccine (Pneumovax, PPV) PPV does not work very well in young children. Children who are under the age of 2 years have a reduced ability to make antibodies to the vaccine and the vaccine is not as effective if given before the age of 2 years. The response to this vaccine is variable and patients with WAS may or may not develop adequate antibody response to the vaccine. The response to the vaccine can be used to determine the severity of the patient with WAS
Children who have previously had their routine immunizations with PCV should also have one injection of Pneumovax as soon as possible after their second birthday (but at least two months after the final dose of PCV).
Children who are under the age of five years who have not previously had routine immunizations with PCV will need both PCV and Pneumovax. The dose schedules depend on age and circumstances. Your doctor will advise you about this.
Meningoccocal Vaccine (MCV4)
Once again, Meningoccocal Vaccine (MCV4) is recommended as these patients are at higher risk of serious disease from the meningococcus. If this vaccine is not available, then the polysaccharide vaccine (MPSV4) may be used. Patients have to be 2 years old to receive the vaccine. A booster is needed if the MPSV4 is used. A booster may be needed with MCV4 depending on the level of immunity after the intial dose and the capacity to sustain that immunity. Under special circumstances the MPSV4 is recommended for patients 3 months to 2 years. They should receive three doses two months apart. In some countries (UK) MenC is recommended to infants at the age of 3 months, and three doses are given 2 months apart.
Influenza vaccine is recommended annually.
Vaccines Recommended prior to and after Splenectomy
If you are about to have your spleen removed, ideally you should be immunized 4-6 weeks before the operation, but at least two weeks before. If this is not possible, you should be immunized two weeks after the operation. As the response to Pneumovax may not be adequate, PCV should also be given.
In people without a working spleen the antibody level gradually falls over time. Therefore, these people should
It may have to be given earlier if the level of antibody decreases.
Pneumovax should be delayed for at least 3 months after immunosuppressive chemotherapy or radiotherapy.
Patients who have not been immunized before should receive Hemophilus B Vaccine preferable at least two weeks prior to the procedure and in case that it was not given, it should be given 2 weeks after the procedure or at the first available opportunity after 2 weeks.
Meningococcal Vaccine MCV4
This should be administered at least 2 weeks prior to the splenectomy. It can only be given after the child is 2 years old. If the patient has not been immunized, they should receive it 2 weeks after the procedure. A booster dose may be needed depending on the antibody titers made to the vaccine.
Influenza vaccine should be given annually
Immunizations for patients on IVIG
Patients on IVIG can receive all the vaccines as per the recommendations for a patient with WAS. However, testing for antibody response may not be possible.
Post-exposure prevention of chicken pox
Several types of exposure can place susceptible persons at risk for chicken pox(varicella). Direct contact exposure is defined as more than 1 hour of direct contact with an infectious person while indoors; substantial exposure for hospital contacts consists of sharing the same hospital room with an infectious patient or having prolonged, direct, face-to-face contact with an infectious person (e.g., health care workers). Brief contacts with an infectious person (e.g., contact with x-ray technicians or housekeeping personnel) are less likely to result in transmission of the virus than are more prolonged contacts. As patients with primary immunodeficiency are susceptible to severe chicken pox and complications from it, Varicella Zoster Immune Globulin (VZIG) is recommended after exposure. Patients who are receiving monthly IVIG at a dose of 400mg/kg or greater are likely to be protected and do not require VZIG if the last dose of IVIG was given less than 3 weeks before exposure.
VZIG provides maximum benefit when administered as soon as possible after exposure, but it may be effective if administered as late as 96 hours after exposure. Effectiveness of VZIG administered more than 96 hours after exposure has not been evaluated and is of uncertain value. VZIG is given intramuscularly. After that period, acyclovir can be used to try and prevent or lessen the severity of the disease.
VZIG is no longer available in the US and Varizig is used in its place. VariZIG can be obtained from the sole authorized U.S. distributor, FFF Enterprises (Temecula, California) (24-hour telephone, 800-843-7477, www.fffenterprises.com . FFF Enterprises delivers VariZIG on an as needed basis (e.g., when there is an identified exposed person for whom VZIG is indicated). Under normal circumstances, the distributor delivers Varizig within 24 hours of request. If Varizig cannot be obtained for some reason, IVIG may be used in its place.
Post-exposure Prevention of Measles
Transmission is particularly likely in homes, schools and in the health care setting. Exposed contacts with the source during the infectious period, from 4 days before to 4 days after onset of rash should be identified. Measles immune globulin is indicated who have been exposed, for whom risk of complications is highest. Measles may be prevented if measles immunoglobulin is given within 72 hours of exposure. Immune globulin can be administered within 6 days of exposure.
Immunization for Transplanted patients
Immunization of Hematopoietic Cell Transplant Recipients(HCT)6 & Immunization of Household Contacts of patients after HCT
Use of live virus vaccines is indicated only among immunocompetent persons and is contraindicated for patients after HCT who are not presumed immunocompetent. HCT recipients are presumed immunocompetent at least 24 months after HCT if they are not on immunosuppressive therapy and do not have GvHD. Other vaccines are recommended and are given at varying times after transplant and under certain circumstances. No data exists for some vaccines.
Immunization of Family Members:
Most routine vaccinations can be given to family members of patients with WAS. The following are some of the restrictions that apply. If family members receive any of these vaccines, then the physician may advise that the patient be isolated from the family member who has received the vaccine7.
1. Chicken Pox: Immunocompromised patients can get disseminated disease with chicken pox. Therefore it is best that the household contacts of the patient receive the varicella vaccine. This reduces the risk of the patient from contracting the "wild type" chicken pox. Data suggest that healthy, vaccinated persons have a minimal risk for transmitting vaccine virus to their contacts8. If the vaccinee develops a rash, contact with the patient should be avoided until the rash resolves, as the patient can get vaccine induced chicken pox. The most frequent time of appearance of the rash is between 7-21 days after the vaccine is given. If inadvertent contact occurs during the period of the rash, there is no need for VZIG or IVIG prophylaxis as the risk of the because disease associated with this type of transmission is expected to be mild 7(Please click on the link to download a pdf file)
2. MMR: MMR can be safely given to household contacts because there are no known cases of transmission of the vaccine virus.7
3. Flumist (LAIV): There is no data assessing the risk of transmission of LAIV from vaccine recipients to immunosuppressed contacts. In the absence of data, use of the inactivated flu vaccine is preferred for vaccinating household members.
4. OPV(Oral Polio Vaccine): This is a vaccine that is no longer given in the US. This vaccine is contraindicated in family members as they can transmit the live virus in the stool and cause polio associated paralysis in the patient. If oral polio vaccine is given inadvertently, then close contact should be limited for 4-6 weeks after vaccination. Increased attention to hygience, especially hand washing may reduce transmission of the virus.
5. BCG: This vaccine is not used in the US. Patients with WAS can acquire infection with the tuberculosis bacteria from the vaccine. This disease can be difficult, if not impossible to treat7.
1. Guide to Contraindications to Vaccination www.cdc.gov
2. Contraindications to Vaccines Chart www.cdc.gov
3. Splenectomy, Hyposplenism and Asplenia Colin Tidy MD EMIS Patient UK 2008
4. A Finn, R Booy, R Moxon, M Sharland, and P Heath. Should the new pneumococcal vaccine be used in high-risk children? Arch Dis Child. 2002 July; 87(1): 18–21.
5. Varicella Vaccine - Q&A about High Risk Recommendations for Postexposure Prophylaxis of Varicella for Persons at High Risk for Severe Disease- Center for Disease Control and Prevention www.cdc.gov
6. Guidelines for Preventing Opportunistic Infections Among Hematopoietic Stem Cell Transplant Recipients- Center for Disease Control and Prevention www.cdc.gov
7. Moss, W, Lederman, MD, H. Immunization Of The Immunocompromised Host. Immune Deficiency Foundation
8. Prevention of Varicella: recommendations of the Advisory Committee on Immunization Practices(ACIP) Center for Disease Control and Prevention www.cdc.gov