It is my understanding that this vaccine is only useful in preventing or delaying the infection of a person with Pseudomonas, but is not helpful for someone who has already been colonized. I am not positive about this, but that is my understanding. Paula, yes, vaccines have side effects and risks. For some vaccines, the risks that can accompany the vaccine are the exact same as the risks that can accompany the illness it is designed to prevent. One reasons for boys not wanting to get chicken pox is the risk of sterility, but a side effect/risk of a boy receiving the vaccine is sterility!? Check out <A href="http://www.vaccineinfo.net">www.vaccineinfo.net</A>. They have some really good info about which formulations of which vaccines are safest and under what conditions. A dilemma for people with CF being vaccinated is that there is greatly increased risk of adverse reaction to the vaccine if you at all ill when it is administered. Another good resource for learning about vaccines is "Take Charge of Your Child's Health" by Dr. George Wootan. There is a great section in the book that describes the dangers of various viruses or diseases and the reasons for vaccinating along with contraindications for vaccinating.My advice is always to weigh each and every vaccination by itself with your personal risk factors for contracting the illness or being adversely affected by the vaccine. There is a reason why many parents are up in arms about their autistic children. Vaccine companies have made mistakes before, but have not been honest with the public about their problems. It is unwise to simply take their word for it that a vaccine is safe for your child. The newer the vaccine, the more hesistant and cautious I recommend being, just as you would/should be with very new drugs.Certain vaccines are more dangerous/risky when received in combinations. For example, there are many reports of side effects of both MMR and DPT, but fewer reposted side effects if the Measles, Mumps and Rubella vaccines are given separately (which is possible, but has to be requested and occassionally prescribed). Diptheria, Pertussis and Tetanus are the same. It is also my understanding that at this time, Medicaid (if that is your child's insurance) cannot require you to vaccinate. You can either choose simply not to do it or to obtain a waiver. There are several different kinds of waivers for vaccination that can be obtained (Medical - if there is reason to assume an adverse reaction will occur or it is contraindicated for your child, Religious - if you are a member of a faith that does not allow vaccination, Conscientious - if your beliefs (other than religious precepts) do not permit you to vaccinate your child). We chose to partially vaccinate our daughter. We weighed what we knew of the illnesses with her personal risk of contracting them. Although we did allow her to have the MMR at age one, she has not received any boosters and will not. Not only did she have a long-lasting reaction to the MMR, my husband had siezures when he received it and on my side of the family the vaccine doesn't take (meaning we do not retain immunity, though the vaccine is properly administered).Feel free to email me (<A href="mailto:jaloughlin3@sbcglobal.net">jaloughlin3@sbcglobal.net</A>) if I can help in your search for information.