FP Vaccine Expert Covers the Waterfront on Immunizations

August 04, 2009 06:10 pm News Staff

There has been no shortage of vaccine-related news this year, with important court rulings, a rise in parental resistance to childhood vaccines and outbreaks of vaccine-preventable illnesses.

To get a perspective on vaccine and immunization issues, AAFP News Now sat down with Doug Campos-Outcalt, M.D., associate chair for the department of Family and Community Medicine at the University of Arizona's College of Medicine, Phoenix, for a wide-ranging discussion on immunizations.

Campos-Outcalt has been a scientific analyst for AAFP since 2006 and also serves as the Academy's liaison to both the CDC's Advisory Committee on Immunization Practices, or ACIP, and the U.S. Preventive Services Task Force.

Q: We're hearing a lot about parental resistance to vaccinations. Is this really a growing concern, or are we just hearing more about it now because it's getting more attention in the mainstream media?

A: The main point to remember is that the vast majority of parents still believe in the value of vaccines and have their children vaccinated. The proportion of parents who are in the area of what I call anti-immunizationists, meaning ardent anti-immunizationists, remains very, very small. The proportion of parents who are in the group that I would refer to as somewhat cautious and concerned about what they're hearing in different venues is probably growing, and I think that's the group we may be hearing about. So the concerned parent who is open-minded and wants to hear more and the parent that the family physicians can talk to and reassure, that group probably is growing. So I think the amount of work that needs to be done to completely immunize a patient population is probably more than it has been in the past because it takes more time for these reassuring type conversations to take place.

Q: What are some of the other barriers doctors have to overcome regarding immunizations in various patient populations?

A: The first is the complication of the vaccine schedule. The more success we have in developing new vaccines that are effective in preventing significant illnesses, the more complicated becomes the vaccine schedule. So it gets harder to keep up with it. That's true for physicians and patients alike.

The second issue has to do with cost. The newer vaccines are more expensive than some of the older vaccines. We're having new products coming out, such as combination vaccines, which, while they reduce the number of injections that are needed, they’re more expensive than the single-antigen products. So the cost of being fully vaccinated is going up, and we have a very fractured system for paying for vaccines. Some children qualify through their insurance. Some qualify through other programs like Vaccines for Children, which is a federal program that pays for vaccines for low-income children. Adults are a whole other matter. There's not as much public funding for adult vaccines, so helping adults stay fully immunized is even more challenging when it comes to costs.

Q: We've seen outbreaks of measles and Haemophilus influenzae type b in the past year. How could, or should, doctors be using those outbreaks to educate parents about the risks of vaccine-preventable diseases?

A: Those outbreaks are very unfortunate for several reasons, one of which is that they're very preventable. Even though these have been small outbreaks compared to the outbreaks we've had in the past, if we do have higher proportions of the population opting not to be vaccinated or not to have their children vaccinated, the inevitable outcome of that will be more outbreaks of these vaccine-preventable illnesses. And I think that's what needs to be emphasized. Parents today just have never seen -- in fact many physicians have never seen -- the illnesses that these vaccines prevent. If you haven't seen a child with measles, you just don't understand how sick they are. If you've never seen a child with Haemophilus influenzae type b meningitis, you don't realize how significant of an illness that it is, that it can cause death and it causes significant sequela if you survive. Those things people don't appreciate, so I think we can take advantage of these very unfortunate situations to impress upon our patients that these are very serious illnesses. Without a fully vaccinated population, (these diseases) will return, and they will cause morbidity and mortality, which is completely preventable with a very safe and effective product.

Q: What about comparing the direct costs of providing vaccines versus the costs imposed by preventable diseases, including lost productivity?

A: Before the Advisory Committee on Immunization Practices makes a recommendation on any vaccine, they now do a cost-benefit analysis. Cost-benefit analyses, of course, are contingent on a number of assumptions. The results are sometimes widely variable, depending on these assumptions, but they still give you some idea of how much vaccines will cost and how much it will save because there are many savings that come from vaccines in terms of not just medical care costs but also lost wages, time out of work and so forth.

One thing you need to keep in mind is that the newer vaccines -- and this has been true for some time -- don't save money, even when you consider all the potential savings that are there. A favorable cost-benefit analysis now will come up with a quality-adjusted, life-year cost of $15,000 to $20,000, and that's quite favorable when it comes to other preventive interventions, like colon cancer screening, breast cancer screening.

Other interventions we know save lives cost as much or more. Vaccines are in that category now in the same range. The days of vaccines actually saving money … if you go back and look at old cost-benefit analysis of vaccines against measles, mumps, rubella, pertussis, things like that, those vaccines actually saved money. You'd spend $1 and save $3. New vaccines are not in that category. These are rarer diseases, and the vaccines are more expensive.

Q: Merck reported in the first quarter that its Gardasil human papillomavirus vaccine sales were off 33 percent compared with the same time last year, and the vaccine has gotten some bad publicity in the mainstream press about adverse events. How does a doctor convince a parent that his or her 11-year-old daughter needs an immunization today that can protect her against sexually transmitted disease and the potential development of genital warts or cervical cancer in the future?

A: The best approach is to ask the parent and the child themselves -- the adolescent or pre-adolescent -- what their concerns are, and then address those factually. And I think having a good command of the facts is important. First of all, safety -- many parents and children are concerned about the safety of the vaccine, and that's usually where the concerns come from. With Gardasil, or human papillomavirus vaccine, there are usually two concerns. One is safety and the second is effectiveness.

In terms of safety, this is a very safe vaccine. The facts are the CDC monitors the safety of this vaccine. You need to reassure people about what we know about the safety of the vaccine, which is that right now there have been no significant, long-term adverse events documented for this vaccine, and then the effectiveness. It's a very effective vaccine against the HPV types that are contained in the vaccine, and there are four types in there. There are types 6 and 8, which cause genital warts, and there are types 16 and 18, which cause cervical cancer. The two types for genital warts cause about 80 to 90 percent of all genital warts currently. The two types that cause cervical cancer cause about 70 percent of all cervical cancers right now.

The third issue to remember regarding this vaccine is the data we have regarding how infectious HPV is. We have very good data to show that it does not take a high number of sexual partners to contract this infection. Within a year or two of initiating sexual activity, within two or three partners, a very high percentage of young females now have contracted one type of HPV virus already. The vaccine is effective only if given before these types of virus are contracted, the types that are in the vaccine. It's important to get it before onset of sexual activity so that you have protection when that comes around.

Q: Is it tough to convince parents when their daughter is 11, or 12 or 13 that they need the vaccine now?

A: I think the issue of facing the reality of impending onset of sexual activity is a hard one for parents to face, and I do think some frank discussions about that are necessary and also some reassurance to parents. There is no evidence that vaccinating against a sexually transmitted disease encourages kids to go out and be sexually active. We've had hepatitis B virus vaccine for some time. Nobody has thought much about it, but that's a sexually transmitted disease. We have a vaccine against it. I've never heard anybody say that they thought kids were going out and having sex because they were protected against hepatitis B virus. Human papillomavirus is only one of a number of sexually transmitted diseases out there. The fact that we're offering protection against four of them is going to encourage children to become sexually active earlier? I just don't think so.

Q: Not long after school starts. it will be time to start thinking about flu shots again. Can you tell us how the formula for the influenza vaccine is developed each year and why sometimes we get a good match and sometimes we don't?

A: Influenza vaccine composition is decided close to a year ahead of the flu season. There's a process where worldwide influenza experts get together. They're monitoring continuously the epidemiology of the flu around the world, what types are where. They make an educated guess as to what the three most common types will be the next year. It's always two type As and one type B. That's the three antigens that go into the vaccine. The reason they have to do it so far in advance is the way the vaccine is produced takes months -- six months or more -- to produce the vaccine, so these decisions have to be made in advance. That does result in better matches some years to what actually happens in the flu season than in others. When there's a really good match, like this last year, the vaccine is more effective. In years where the match is not so good, it doesn't mean the vaccine is not effective, it just means it's less effective.

Q: Sometimes, even when we have a good match, we can end up with a shortage or distribution issues. What are some of the things that can derail flu vaccinations?

A: We haven't had a true shortage for several years now. That resulted in some problems in production of one particular supplier or manufacturer. Something like that can happen, but even that year we had leftover vaccine. Sometimes, the problems are more distribution than they are the actual supply of the vaccine. The distribution system tends to be more of a local issue. There may be plenty of vaccine available, but locally, there may be a shortage because of a distribution problem of some kind. Those things can happen, and the American Academy of Family Physicians tries hard to help state chapters and family physicians around the country work out some of those issues when they do occur.

Q: Can you walk us through the ACIP process? How does that committee work, and is it a difficult or lengthy process to get a recommendation approved?

A: The process starts with what we call working groups. The ACIP itself has 15 members on it, and then there are a number of other stakeholders and professionals involved. For instance, at the AAFP, we have a number of our members who have some interest and expertise in immunizations and vaccines on some workgroups. The workgroups meet monthly, usually by telephone via conference calls to begin to discuss the issues around, say influenza or rotavirus or human papillomavirus -- whatever the topic of the working group is. They will have data presented to them regarding vaccines that are in the pipeline, so they monitor vaccines that are in various stages of production or pre-approval, where they're at and when they're likely to come before the FDA so they can anticipate licensure.

Once licensed, the workgroup will consider the data for effectiveness, the cost-benefit analysis we've talked about, the epidemiology of the disease, who it affects, what's the significance of it, what the trends have been. All these things will be considered, and then a series of potential recommendations will be considered. Based on the best evidence that the ACIP has, the workgroup will make a recommendation to the ACIP itself. At the ACIP meeting -- these take place three times a year, they're full two-day meetings each time -- the ACIP will hear from the workgroup. Represented by the chair, the workgroup will present their data, everything that went into their deliberations, their reasoning and their recommendations.

The ACIP as a whole then debates these, sometimes accepts these recommendations as the workgroups present (them), sometimes modifies them, sometimes sends it back for further work if they're not satisfied that enough is known at that point. At some point in time, there is a final vote, and a recommendation is made. That can include several options, which is universal use, more restricted use, what they call permissive use -- meaning it's kind of optional rather than recommended for everybody -- or recommend against in certain groups. And there's always lots of little contingencies that have to be thought through in this. Some groups -- HIV positive (patients) and other immunocompromised (patients) have to be thought of, pregnant women have to be thought about, and recommendations have to include consideration of each of those.

Q: You mentioned pregnant women. Why are they so undervaccinated as far as flu shots go? They have the lowest uptake among high-risk groups. There seems to be a lot of misinformation out there.

A: There have been some changes in the recommendations that have caused some confusion about that. We also have two types of flu vaccine now, one of which is licensed for use in pregnancy and one which isn't. The live, attenuated influenza vaccine is not, whereas the trivalent influenza vaccine -- which is the injection -- is. And it's perfectly safe to give in pregnancy. The recommendations are that if you're pregnant during flu season, you should have the vaccine. This will go away in the near future, this whole confusion, because we're moving down a path of universal recommendations for flu vaccine for virtually everybody unless contraindicated annually in the United States. That's two or three years away, probably.

Q: What are some of the coming enhancements or improvements in vaccine development members should be aware of?

A: There are a number of products in the pipeline. For instance, different pneumococcal vaccines. They will probably replace some of the products that we have now or at least complement them. There's an increasing number of combination vaccines available. While you might think at first that would simplify the vaccine schedule by combining vaccines into one injection, it doesn't really because now you have varying products with different combinations. It does complicate, a little bit, the schedule when you start using these combination products. I do think there's going to be some effort made to help with that. And then there will be new routes of administration. I'm not sure how long this will be. I'll go out on a limb and say within 10 years, I think we're going to have vaccines that are administered through routes other than injections. We already have the live, attenuated influenza vaccine, which is intranasal. I think we're going to have more of those. I think there will be some very creative routes of administration of vaccines, and it will be a lot more acceptable than injections. Those are going to come out in the future as well.

Q: Doctor, do you have any final thoughts on this topic of vaccines?

A: There is another series of events which I think family physicians ought to be aware of, and that's a couple of very encouraging events having to do with the vaccine-autism issue. And I don't call it a controversy, because in my mind, it's not a controversy. The scientific community and every group that's ever looked at this with rigorous, evidence-based methodology has concluded that vaccines do not cause autism. That is not a controversy. It is an issue that certain groups continue to raise.

Two significant events recently have -- I hope -- started to put an end to that. One is that the Vaccine Injury Compensation program has had several rulings come down where the courts have looked at the evidence and concluded -- and they're very strongly worded opinions -- that the evidence presented by the plaintiffs was weak. Their scientific experts were not credible, and there was nothing to those claims. That was a very significant event. And you're beginning to see some fractionation of the autism groups themselves. You're seeing some thoughtful parents who have been in autism support groups and advocacy groups saying, "Wait a minute, we need to go a different direction here. The vaccine thing is not fruitful. We need to put money in research in areas that's going to yield results. We need to find the cause of autism." They're splitting off from these more strident anti-immunization groups. And I think that's a very significant event as well.