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Adult Immunizations

I'm going to cover adult immunization. Immunization involves the administration of immunobiologicals which are able to confer either active or passive immunity immunizations, vaccines, imunization, vacine. Active immunity is the ability of the biological to elicit an ongoing immune response that may or may not be life-long, but at least it is an active process on the part of the immune system, as opposed to the delivery of immune globulins, which have a life expectancy in the host after they are delivered and will wane over time. So their protective efficacy is relatively short lived.

Intravenous immune globulin is one of those ideas that is deeply rooted, I think, in our medical consciousness over the past century; it is something that seems to make sense. If you don't have time to give a vaccine where there isn't a vaccine available and there isn't time to mount active immunity over a period of time, it would seem to make sense to deliver something that will have some immediate protective efficacy. For example, in Africa during the most recent outbreak of Ebola virus disease.

The licensed live vaccines that we have available to us are the following: adenovirus vaccine, which is not widely used; BCG, which is perhaps the most widely used live vaccine in the world. BCG is bacillus Calmette-Guerin. It is an attenuated strain of Mycobacterium bovis. It was developed at the Institute Pasteur more than a hundred years ago and it is widely administered.

Measles, mumps, rubella of course is a live-attenuated strain of these viruses and it has been available since the 1960's. I'll say more about that in a bit. Regarding polio - we are now on the verge of eradicating it from the globe. A few years back it was declared eradicated in the Western Hemisphere. There has not been a case in the Western Hemisphere now of wild-type polio in several years. Every year, there are five or six cases of polio that are vaccine related.

Typhoid vaccine is a live vaccine strain of Salmonella typhi, only widely used in travelers to typhoid-endemic areas. Varicella is our newest live vaccine; it came onto the market within the last couple of years and is now recommended.

The inactivated vaccines include anthrax vaccine, and I had a question coming in this morning about the utility of anthrax vaccine. This is clearly a vaccine that is not up to the standard of modern vaccine production but it really is all that we have at this point in time. It really needs to be part of our bioterrorism preparedness, particularly for troops in theater.

We now have acellular pertussis vaccine, which ought to be the widely used strain of diphtheria, tetanus and pertussis vaccine. That can be used in combination with Haemophilus influenza type B vaccine for kids to develop immunity to these four infectious agents that have been a scourge in childhood for so long. The conjugate strain of the vaccine is really more efficacious, more immunogenic and has fewer side effects.

Influenza vaccine, as you know, changes from year to year, but this is a virion subunit - a virus subunit vaccine that does not contain live virus, so for all of those patients of yours who come back every year and tell you that they got the flu after getting the flu shot, it's not true and I try to tell our health care workers every year that it can't happen. The idea that every feverish, achy illness is the flu is so deeply embedded in the lay consciousness that that concept that the flu shot caused the flu is really hard to shake. When you immunize as many people as we do every year with influenza vaccine, certainly some of them are going to have febrile illnesses within a few weeks, and certainly over the course of a flu season, some of those people will have para-influenza or respiratory syncytial virus, adenovirus infections or what have you. Of course, the flu vaccine is not perfectly protective; it only has an efficacy of about eighty percent. But it is a safe and inactivated vaccine that can be administered to just about everyone except those who have hypersensitivity reactions to eggs or who have had a prior problem with the vaccine.

Japanese encephalitis vaccine is an inactivated strain of Japanese encephalitis virus. Really, it is only given in the U.S. to individuals traveling to parts of the world where Japanese encephalitis is endemic and to individuals who will be working in areas directly where it is endemic for a prolonged period of time.

Meningococcal vaccine is an inactivated vaccine used to prevent meningococcemia and meningococcal meningitis. This is now being recommended more widely than it had been in the past. This previously was reserved for use in travelers, primarily the sub-Saharan Africa and some areas of India where there are ongoing epidemics of meningococcal meningitis and meningococcemia. It is now being recommended for administration to college students. The data on meningococcal meningitis among college students is that as a whole, the college-aged population is not at a greater risk than the rest of the population for developing meningococcal meningitis, or meningococcemia. They do fit the classic demographic of someone who gets meningococcemia, however - someone who lives in a congregate setting - an Army barracks, a dormitory, an athletic team situation - those are the kind of situations where you see meningococcal meningitis. But when you stratify the college-aged population by their age and school and what they are doing in school, it turns out that the freshman class living in the dormitory is at greater risk than the population as a whole. Over the course of the four years, it evens out to about the same risk as the rest of the population. So meningococcal vaccine is now recommended by student health services and by the CDC for administration to college students at the time of entry. We have an enormous campaign at our institution.

Pneumococcal vaccine, of course, is a 23-serotype polysaccharide vaccine that has mixed efficacy, but looking at it by serotype by serotype, there is a good response to each of the individual serotypes. Overall, the protective effect is less for those