FREQUENTLY ASKED QUESTIONS

MELATONIN (Jet-Lag tablets)

Melatonin is a natural hormone that is produced by the pineal gland which is located in the brain.   It is secreted at night and sets the internal biological clock that governs our cycles or rhythms.  Certain enzymes in the pineal gland are active by darkness, so as the sun goes down melatonin is released and sleep results.   As morning approaches and light intensifies, melatonin levels decrease and we awaken after a restful sleep. If adequate levels are not produced or are not produced at the proper time, we cannot experience cycles.

Melatonin helps to set and control the internal clock that governs the natural rhythms of the body.  Melatonin may have a powerful role as an antioxidant along with anti-ageing and immune system enhancing properties.  Melatonin may also play a role in the treatment of prostate enlargement and as an addition to cancer treatment.  Melatonin is an effective tool to prevent or cure jet lag, and an ideal supplement to reset the biological clock in shift workers, and may greatly help people who suffer from insomnia.

ASPECTS OF VACCINATIONS

In general, a person in good health may receive simultaneous doses of several vaccines antigens at different anatomic sites without effect on the level of protective efficacy elicited. The number of doses may be limited, however, by the tolerance of the recipient for multiple injections. Also the known side effects associated with each individual vaccine may be accentuated by simultaneous immunisation should be considered.

Inactivated vaccines may be given simultaneously at different sites, or at different times together with other inactivated or live vaccines without interfering with the immune response. An exception is the case of YELLOW FEVER AND CHOLERA VACCINES THAT SHOULD NOT BE GIVEN ON THE SAME DAY.

In general, if possible, DOSES OF LIVE VACCINES SHOULD BE GIVEN ON THE SAME DAY OR 30 DAYS APART, because of the theoretical concerns about interference with the antibody response when the live virus vaccines are given at different times within 30 days of each other. PPD SKIN TESTING SHOULD BE DONE ON THE SAME DAY AS LIVE VIRUS VACCINES ARE BEING GIVEN, OR 4 TO 6 WEEKS AFTERWARDS, because the live virus vaccines can impair the recipient's response to the PPD skin test.

Vaccines containing ATTENUATED LIVE VIRUSES ARE GENERALLY CONTRAINDICATED IN PREGNANT AND LACTATING WOMEN, YOUNG INFANTS, PEOPLE WITH CHRONIC ILLNESS, AND PEOPLE WITH IMMUNOSUPPRESSION DUE TO HIV INFECTION, CORTICOSTEROID THERAPY, CHEMOTHERAPY, OR RADIATION THERAPY. These groups of travellers merit special consideration.

Immunisation with a LIVE VIRUS VACCINE FOR MEASLES MUMPS OR RUBELLA, SHOULD BE DONE AT LEAST 2 WEEKS BEFORE OR 3 MONTHS AFTER RECEIPT OF IMMUNE GLOBULIN. IMMUNE GLOBULIN DOES NOT APPEAR TO INTERFERE WITH THE IMMUNE RESPONSE TO ORAL POLIO(OPV) AND YELLOW FEVER VACCINES, NOR DOES IT INTERFERE WITH THE RESPONSE TO THE INACTIVATED VACCINES. Conversely, gamma globulin does not seem to check the vaccinal response following immunisation with vaccines prepared using killed microrganisms(DTP, POLIO, TETANUS, RABIES, HEPATITIS B, etc.) However, some authors do believe that the quality of immunisation is not as GOOD.

SUMMARY OF PRINCIPLES FOR VACCINATING IMMUNOCOMPROMISED PERSONS

The degree to which an individual patient is immunocompromised should be determined by a physician.
Causes of immunosuppression can be due to the following:
•  Congenital immunodeficiency
•  HIV
•  leukaemia
•  lymphoma
•  generalised malignancy
•  therapy with alkylating agents
•  antimetabolites
•  radiation
•  large amounts of corticosteroids
The responsibility for determining whether a patient is severely immunocompromised, ultimately lies with the physician.

KILLED OR INACTIVATED VACCINES DO NOT REPRESENT A DANGER TO IMMUNOCOMPROMISED PERSONS AND GENERALLY SHOULD BE ADMINISTERED AS RECOMMENDED FOR HEALTHY PERSONS. FREQUENTLY THE IMMUNE RESPONSE OF IMMUNOCOMPROMISED PERSONS TO THESE VACCINE ANTIGENS IS NOT AS GOOD AS THAT OF IMMUNOCOMPETENT PERSONS; HIGHER DOSES OR MORE FREQUENT BOOSTERS MAY BE REQUIRED, ALTHOUGH EVEN WITH THESE MODIFICATIONS, THE IMMUNE RESPONSE MAY BE SUBOPTIMAL.

Virus replication after administration OF LIVE ATTENUATED VACCINES CAN BE ENHANCED IN SEVERELY IMMUNOCOMPROMISED PERSONS. IN GENERAL, THESE PATIENTS SHOULD NOT BE ADMINISTERED LIVE VACCINES, WITH THE EXEPTIONS NOTED BELOW.
IN ADDITION OPV SHOULD NOT BE ADMINISTERED TO ANY HOUSEHOLD CONTACT OF A SEVERELY IMMUNOCOMPROMISED PERSON.
MMR (Measles-Mumps-Rubella) vaccine is not contraindicated for the close contacts (including health-care providers) of immunocompromised persons.

LEUKEMIA

Persons with leukaemia in remission who have not received chemotherapy for at LEAST 3 MONTHS ARE NOT CONSIDERED SEVERELY IMMUNOSUPPRESSED FOR THE PURPOSE OF RECEIVING A LIVE-VIRUS VACCINES.
When cancer chemotherapy or immunosuppressive therapy is being considered (e. g., for patients with Hodgkin's disease or organ transplantation), vaccination ideally should precede the initiation of chemotherapy or immunosuppression by > 2 weeks. VACCINATION DURING CHEMOTHERAPY OR RADIATION THERAPY SHOULD BE AVOIDED BECAUSE ANTIBODY RESPONSES ARE SUBOPTIMAL. PATIENTS VACCINATED WHILE ON IMMUNOSUPPRESSIVE THERAPY OR IN THE 2 WEEKS BEFORE STARTING THERAPY SHOULD BE CONSIDERED UNIMMUNISED AND SHOULD BE REVACCINATED AT LEAST 3 MONTHS AFTER DISCONTINUATION OF THERAPY. Passive immunoprophylaxis with immune globulins may be indicated.
CHILDREN WITH LEUKEMIA MAY BE VACCINATED AGAINST MEASLES , PROVIDED CHEMOTHERAPY IS DISCONTINUED AT LEAST 3 MONTHS BEFORE VACCINATION .
While immunization with any live attenuated vaccine should be prohibited in cancer patients, and especially in those receiving immunosuppressive treatment,the killed or inactivatedccines, toxoids and polysaccharide vaccines are generally well tolerated.

STEROID THERAPY

Steroid therapy usually does not contraindicate administration of live-virus vaccines when such therapy is short term(< 2 weeks); low or moderate dose, long-term alternate day treatment with short-acting preparations; maintenance physiologic doses(replacement therapy); or administered topically (skin or eyes), by aerosol, or by intra-articular, bursal, or tendon injection. The exact amount of systemic corticosteroids and the duration of their administration needed to suppress the immune system of an otherwise healthy child are not well defined. The immunosuppressive effects of steroid treatment vary, but many clinicians consider a dose equivalent to either 2 mg /kg of body weight or a total of 20mg/day of prednisone as sufficiently immunosuppressive to raise concern about the safety of immunisation with live-virus vaccines. Physicians should WAIT AT LEAST 3 MONTHS AFTER DISCONTINUATION OF THERAPY BEFORE ADMINISTERING A LIVE -VIRUS VACCINE TO PATIENTS WHO HAVE RECEIVED HIGH-DOSE, SYSTEMIC STEROIDS FOR > 2 WEEKS

HIV-INFECTED PERSONS.

In general, people known to be infected should not receive live-virus or live-bacteria vaccines.
DR DES MARTIN SUGGESTS A CD4 COUNT (500 OR LESS) SHOULD BE A GIDELINE.
•  Limited studies of MMR vaccination among both asymptomatic and symptomatic HIV-infected patients have not documented serious or unusual adverse events.
•  ENHANCED INACTIVATED POLIO VACCINE IS THE PREFERED POLIO VACCINE FOR PEOPLE WITH HIV INFECTION.
•  PNEUMOCOCCAL VACCINE IS INDICATED FOR ALL HIV-INFECTED PERSONS > 2 YEARS OF AGE.
•  CHILDREN < 2 YEARS WITH KNOWN HIV INFECTION SHOULD RECEIVE HIB TITER ACCORDING TO THE ROUTINE SCHEDULE.
•  INFLUENZA VACCINE SHOULD BE OFFERED TO ALL HIV PATIENTS

In general, symptomatic HIV-infected children and adults have suboptimal immunologic responses to vaccines.The response to both live and killed antigens may decrease as the HIV disease progresses. Persons with HIV infection have an inpaired response to Hep B vaccine.
The anti-Hbs response should be tested after they are vaccinated, and those who have not responded should be revaccinated with 1-3 additional doses.

MEDICAL CONDITIONS ASSOSIATED ONLY WITH SPECIAL INDICATIONS FOR VACCINES.

RENAL FAILURE

Patients with renal failure have an increased risk of infection with a variety of pathogens, particularly pneumococcus and hepatitis.

•  Hep B especially indicated for patients whose renal disease is likely to lead to dialysis or transplantation.
•  Pneumococcal vaccine is reccomended for children > 2 years especially with nefrotic syndrome.
•  Should receive annual influenza vaccine.

DIABETES

•  Pneumococcal vaccine is safe and effective for these patients and does not interfere with insulin or oral antidiabetic agents.
•  Annual influenza vaccine

ALCOHOLIC CIRRHOSIS

•  One time pneumococcal vaccine
•  Yearly influenza vaccine

ASPLENIA

•  Pneumococcal vaccine in patients > 2 years old.
•  Meningococcal vaccine
•  HIB vaccine is immunogenic in splenectomised adults and may be considered for this group.
When elective splenectomy is planned, vaccination with PNEUMOCOCCAL, MENINGOCOCCAL, AND HIB VACCINES SHOULD PRECEDE SURGERY BY AT LEAST 2 weeks,if possible.
IT SHOULB BE EMPHASIZED THAT IMMUNIZATION WITH A LIVE ATTENUATED VACCINE IS CONTRAINDICATED IN SPLENECTOMY PATIENTS, WHEREAS THE USE OF AN INACTIVATEDCCINE, A POLYSACCARIDE OR A TOXOID VACCINE PRESENTS NO RISK.