Vaccines currently licensed

Rifaximin is likely to be effective in the treatment of milder forms of shigellosis and has been shown to be effective at preventing infection owing to S. flexneri.10 Antimotility agents are not recommended because they can worsen dysentery and may be related to the development of toxic megacolon. No vaccines are licensed currently for the prevention of shigellosis. 

Prior to measles vaccine availability the number of cases of measles approached the birth rate of approximately 3 to 4 million annually. The first measles vaccine was licensed in 1963. Since that time there has been a 99% reduction in reported measles cases. Currently, there is a goal to eliminate measles transmission in the United States through aggressive immunization programs. 

Most vaccines are administered in two- to four-shot series in order to elicit the best protection. Childhood and adult immunization schedules are revised frequently and published annually by the CDC Advisory Committee on Immunization Practices. Current immunization schedules can be found at www.cdc.gov/nip/. The childhood schedule is published in January and the adult schedule in October of each year. Recommendations will be published throughout the year in the Morbidity and Mortality Weekly Report (MMWR) as new vaccines are licensed or new information necessitates a change in previous recommendations. 

Two inactivated virus vaccines are currently licensed in the United States, Havrix and Vaqta. Approved dosing recommendations are shown in Table 25-3. Seroconversion rates >94% are achieved with the first dose. 

This schedule indicates the recommended ages for routine administration of currently licensed childhood vaccines, as of December 1,2006, for children aged 0-6 years. Additional information is available at http //www.cdc.gov/nip/recs/child-schedule.htm. Any dose not administered at the recommended age should be administered at any subsequent visit, when indicated and feasible. Additional vaccines may be licensed and recommended during the year. Licensed combination vaccines may be used whenever any components of the combination are indicated and other components of the vaodne are... 

These schedules indicate the recommended age groups and medical indications for which administration of currently licensed vaccines is commonly indicated for adults ages 19 years and older, as of October 1,2007, Licensed combination vaccines maybe used whenever any components of toe combination are indicated and when the vaccine s other components are not contraindicated. For detailed recommendations on all vaccines, including those used primarily for travelers or that are issued during toe year, consult the manufacturers package inserts and the complete statements from toe Advisory Committee on Immunization Practices (wmcdc.gov/vaccines/pubs/acip-list.htm). ... 

Two types of trivalent poliovirus vaccines are currently licensed for distribution in the United States an enhanced inactivated vaccine (IPV) and a live attenuated, oral vaccine (OPV). IPV is the recommended vaccine for the primary series and booster dose for children in the United States, whereas OPV is recommended in areas of the world that have circulating poliovirus. 

Liposomes are phospholipid vesicles that have been evaluated both as adjuvants and as vehicles for antigens and adjuvants (17). A liposomal hepatitis A (Hep A) vaccine (virosomes) has been extensively evaluated in the clinic and is currently licensed for a Hep A vaccine (18). Alternative adjuvants that have been used in a few products include L-tyrosine (allergy vaccine) and MPL (cancer treatment). The various adjuvants (mainly alum salts) used in vaccine formulations and their quantities per dose are listed in Table 1. 

Note All of these adjuvants have been evaluated in clinical trials with the exception of cochleates and polymerized liposomes. Only those adjuvants marked are currently licensed as adjuvants in approved vaccine products. 

This schedule indicates the recommended ages for routine administration of currently licensed childhood vaccines, as of December I, 2006, for children aged 7-18 years, Additional information is available at http //www.cdc.gov/nip/recs/child-schedule.htm. 

An anthrax vaccine is available but its use is currently reserved for laboratory personnel who may come in contact with the disease and for military personnel. The vaccine currently in use by the United States military is a sterile, acellular vaccine known as AVA (Anthrax Vaccine Adsorbed). It is not currently licensed for use with civilian populations, although there are protocols under investigation. 

Japanese encephalitis vaccine has been reviewed (2). A supplementary volume of the journal Vaccine has dealt with results presented at a WHO meeting held in Bangkok, Thailand, in 1998 (3-6). Comprehensive data were provided on the epidemiological and virological situation in southeast Asia and Australia, control measures, vaccine production capacities, and different vaccines against Japanese encephalitis. Adverse events after the use of inactivated mouse brain vaccine (the only vaccine that is currently licensed for international use) have been reviewed in detail (3). 

TABLE 40—8. Recommended Doses and Schedules of Currently Licensed Hepatitis B Vaccines... 

Vaccines also may be used to boost specific immune processes directed against the bacteria themselves or against adherence appendages, cytotoxins, or enterotoxins. Currently available vaccines for typhoid fever in the United States are the parenteral Vi capsular polysaccharide vaccine, the oral live-attenuated Ty21a vaccine, and the older heat-phenol-inactivated parenteral vaccine. Only the older parenteral cholera vaccine is licensed for use in the United States, but it is not recommended owing to the low risk of cholera to the traveler and the limited efficacy of the vaccine. New oral five and killed vaccines are licensed outside the United States and are used by some travelers. The rotavirus vaccine, although effective, has presented complications in the form of rare cases of intussusceptions it is no longer marketed and thus is not recommended. ... 

This schedule indicates the recommended age groups for routine administration of currently licensed vaccines for persons 19 years of age and older. Licensed combination vaccines may be used whenever any components of the combination... 

The only vaccine adjuvants currently licensed by the FDA are aluminium salts. All other adjuvants are considered experimental and must undergo special preclinical testing. In the search for well-characterized adjuvants, the saponins from Quillaja saponaria, having quillaic acid as aglycone were shown to be potent immune adjuvants, such as Quil A (a purified mixture of 23 saponins), Iscoprep 7 0 3 which is a mixture of well characterized saponin fraction QH-A, QH-B, QH-C in a ratio 7 0 3 and the pure saponins QS-7, QS-17, QS-18, QS-21 (31) [41] (see Fig. (2)) and QS-L1 (32) [42]. 

There have been no controlled clinical trials in humans of the efficacy of the currently licensed U.S. vaccine. This vaccine has been extensively tested in animals and has protected guinea pigs against both an intramuscular6061 and an aerosol challenge.59 The licensed vaccine has also been shown to protect rhesus monkeys against an aerosol challenge.5868... 

Although an effective Q fever vaccine is licensed in Australia, all Q fever vaccines used in the United States are currently investigational. Certain groups of individuals should be considered for vaccine prophylaxis, including the following ... 

The vaccine currently available is a toxoid that protects from serotypes A through E. This material is used under Investigational New Drug (IND) status, with a license held by the Centers for Disease Control and Prevention (CDC), Atlanta, Georgia. The toxoid was developed by scientists at Fort Detrick, Frederick, Maryland, during the 1950s.3 It is a formalin-fixed crude culture supernatant from strains of C botulinum that produce the appropriate serotypes. Vaccinations are administered at 0, 2, and 12 weeks, followed by annual booster doses. 

Adjuvants comprise a heterogeneous group of compounds. The only vaccine adjuvants currently licensed for human use are aluminium salts. All other adjuvants are considered experimental and must undergo special preclinical testing. Some triterpene saponins, most notably those originating from Quillaja saponaria, are potent immune adjuvants [9]. 

A large and rapidly growing number of clinical trials (phase I and phase II) evaluating the potential of DNA vaccines to treat and prevent a variety of human diseases are currently being performed ( http // clinicaltrials.gov) however, there is yet no licensed DNA vaccine product available for use in humans. The clinical trials include the treatment of various types of cancers (e.g., melanoma, breast, renal, lymphoma, prostate, and pancreas) and also the prevention and therapy of infectious diseases (e.g., HIV/ABDS, malaria, Hepatitis B vims, Influenza vims, and Dengue vims). So far, no principally adverse effects have been reported from these trials. The main challenge for the development of DNA vaccines for use in humans is to improve the rather weak potency. DNA vaccines are already commercially available for veterinary medicine for prevention of West Nile Vims infections in horses and Infectious Hematopoetic Necrosis Vims in Salmon. 

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