This invention, in one aspect, relates to synthetic immunoreactive peptides. These peptides are approximately 20-25 amino acids in length which are portions of the N termini of the M proteins of the most prevalent United States (U.S.) Group A Streptococcus (GAS) serotypes. At least some of the synthetic peptides can be recognized by M type-specific antibodies and are capable of eliciting functional opsonic antibodies and/or anti-attachment antibodies without eliciting tissue cross-reactive antibodies. In another aspect, it relates to compositions or vaccines comprising these synthetic serotype-specific peptides, including polypeptides and proteins. The invention may also be isolated antibodies which are raised in response to the peptides, compositions or vaccines. The invention further relates to kits for using the peptides, compositions, or antibodies. In still further aspects, the invention also relates to methods for using the peptides, compositions, vaccines, or antibodies and methods for tailoring vaccines.

Description of the Invention

SUMMARY OF THE INVENTION

In accordance with the purpose(s) of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to immunoreactive peptides. In another aspect, it relates to compositions or vaccines comprising the peptides, including polypeptides and proteins.

The synthetic peptides of the invention are approximately 20-25 amino acids in length which are portions of the N termini of the M proteins of the most prevalent United States (U.S.) GAS serotypes and which are immunoreactive. At least some of the synthetic peptides can be recognized by M type-specific antibodies and are capable of eliciting functional opsonic antibodies and/or anti-attachment antibodies without eliciting tissue cross-reactive antibodies.

The invention is also a composition or a vaccine comprised of these synthetic serotype-specific peptides of 20-25 amino acids in length from GAS M proteins. The peptides can be used, for example, individually, in a mixture, or in a polypeptide or protein. Examples of ways the polypeptide or protein can be created include fusing or linking the peptides to each other, synthesizing the polypeptide or protein based on the peptide sequences, and linking or fusing the peptides to a backbone. Also, a liposome may be prepared with the peptides conjugated to it or integrated within it. The compositions or vaccines may further comprise additional components, including but not limited to, carriers, vehicles (e.g., encapsulated, liposomes), and other immune-stimulatory molecules (e.g., adjuvants, other vaccines). Additionally, a DNA vaccine comprising DNA encoding the peptides or compositions of the present invention is disclosed.

The invention may also be isolated antibodies which are elicited in response to the peptides, compositions or vaccines.

In further aspects, the invention also relates to methods for using the peptides, compositions, vaccines, or antibodies and methods for tailoring vaccines. The invention still further relates to kits for using the peptides or antibodies, which can, for example, be used for diagnostic purposes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one aspect, the present invention provides synthetic peptides, compositions, and a vaccine made therefrom and isolated antibodies elicited by administration thereof. The invention also provides methods for using the peptides, compositions, vaccines, or antibodies such as, vaccination of recipients. The invention further provides a method for tailoring vaccines. The invention additionally provides kits for using the peptides or antibodies.

Peptides

The invention is synthetic peptides of approximately 20-25 amino acids in length selected from a section of approximately 45 amino acids from the most N terminal region of the M proteins of the most prevalent U.S. Group A Streptococcus (GAS) serotypes which are immunoreactive. At least some of the peptides are capable of eliciting opsonic antibodies and/or anti-attachment antibodies to the GAS serotypes without eliciting tissue cross-reactive antibodies. In one aspect of the invention, the synthetic peptides are from the most prevalent invasive U.S. GAS serotypes which are immunoreactive. The prevalence data in FIG. 1 (see Original Patent) includes data from invasive isolates. The most frequently occurring invasive types reflect the incidence rate of the same types found in non-invasive isolates. Specific peptides of the present invention are shown below in Table 1 (see Original Patent). One aspect of the invention is a peptide consisting essentially of the amino acid sequence of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO:50, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:53, SEQ ID NO:54, SEQ ID NO:55, SEQ ID NO:56, SEQ ID NO:57, SEQ ID NO:58, SEQ ID NO:59, SEQ ID NO:60, SEQ ID NO:61, SEQ ID NO:62, SEQ ID NO:63, SEQ ID NO:64, SEQ ID NO:65, SEQ ID NO:66, SEQ ID NO:67, SEQ ID NO:68, SEQ ID NO:69, SEQ ID NO:70, SEQ ID NO:71, SEQ ID NO:72, SEQ ID NO:73, SEQ ID NO:74, SEQ ID NO:75, SEQ ID NO:76, SEQ ID NO:77, SEQ ID NO:78, SEQ ID NO:79, SEQ ID NO:80, SEQ ID NO:81, SEQ ID NO:82, SEQ ID NO:83, SEQ ID NO:84, SEQ ID NO:85, SEQ ID NO:86, SEQ ID NO:87, SEQ ID NO:88, SEQ ID NO:89, SEQ ID NO:90, SEQ ID NO:91, SEQ ID NO:92, SEQ ID NO:93, SEQ ID NO:94, SEQ ID NO:95, SEQ ID NO:96, SEQ ID NO:97, SEQ ID NO:98, SEQ ID NO:99, SEQ ID NO:100, SEQ ID NO:101, SEQ ID NO:102, SEQ ID NO:103, SEQ ID NO:104, SEQ ID NO:105, SEQ ID NO:106, SEQ ID NO:107, SEQ ID NO:108, SEQ ID NO:109, SEQ ID NO:110, SEQ ID NO:111, SEQ ID NO:112, SEQ ID NO:113, SEQ ID NO:114, SEQ ID NO:115, SEQ ID NO:116, SEQ ID NO:117, SEQ ID NO:118, SEQ ID NO:119, SEQ ID NO:120, SEQ ID NO:121, SEQ ID NO:122, SEQ ID NO:123, SEQ ID NO:124, SEQ ID NO:125, SEQ ID NO:126, SEQ ID NO:127, SEQ ID NO:128, SEQ ID NO:129, SEQ ID NO:130, SEQ ID NO:131, SEQ ID NO:132, SEQ ID NO:133, SEQ ID NO:134, SEQ ID NO:135, SEQ ID NO:136, SEQ ID NO:137, or SEQ ID NO:138.

Examples of the peptides of the invention, several for each of the 25 most common serotypes (138 peptides), are as follows -- see Original Patent.

It is important to note that a single peptide representing each of the 25 M serotypes represented is predicted to protect against the majority of invasive GAS within each of these serotypes in the U.S. For the majority of these types, the invention provides a peptide that actually matches the sequences of all GAS of these types that we have encountered. We include additional peptides that encompass the extent of M protein gene allelic variation that we have encountered to date within each type from various geographic locations. It is important to note that for the majority of these types, at least one peptide is conserved among all allelic variants that we have encountered.

The small size of the peptides used in the current invention allows a flexible approach for formulating compositions or vaccines. The formulations can be readily and inexpensively changed to account for changes in GAS serotype frequencies in the target population. The adaptability includes frequency changes between populations, years, and the like. Any population for which there is frequency data can have a vaccine formulation customized for it by the methods of the present invention, which are discussed below.

Recently a rapid M protein gene-based subtyping system has been initiated which predicts the type-specific portion of the M protein with very high efficiency. (Beall, B., Facklam, R., Hoenes, T., Schwartz, B. 1997. A survey of emm gene sequences from systemic Streptococcus pyogenes infection isolates collected in San Francisco, Calif.; Atlanta, Ga.; and Connecticut state in 1994 and 1995. J. Clin. Microbiol. 35:1231-1235; Beall, B., Facklam, R, Elliot, J., Franklin, A., Hoenes, T., Jackson, D., Laclaire, L., Thompson, T., Viswanathan, R. 1998. Streptococcal emm types associated with T-agglutination types and the use of conserved emm restriction fragment patterns for subtyping group A Streptococci. J. Med. Micro. 47:1-6). A Centers for Disease Control and Prevention (CDC) surveillance system used this rapid gene based M subtyping system to gather epidemiological data which showed that the 30 most prevalent invasive serotypes account for approximately 95% of the total invasive isolates in the U.S.

In addition, these peptides should have direct use in formulating vaccines for countries other than the U.S. For example, the 25 serotypes represented in Table 1 also appear to encompass the majority of GAS pediatric pharyngitis isolates in Rome, Italy ( 91/114=80%), 85% ( 367/430) of a mixture of sterile and non-sterile GAS isolates recovered in Mexican patients, and 80% ( 110/137) of primarily invasive isolates recently recovered from patients in Argentina.

It is also important to note that data indicates that these 25 serotypes would have less coverage in other geographic areas such as Malaysia, India, New Guinea, Nepal, and Egypt. For example, out of 136 pharyngitis and impetigo isolates recently recovered in Egypt, only 62 (46%) were of one of these 25 types. While type emm1 is by far the most prevalent type recovered from invasive and noninvasive U.S. isolates (about 20%), only 5/136 (40%) Egypt isolates were type emm1. Thus, the methods of the present invention could be used to tailor vaccines or compositions with the serotypes most prevalent in these areas.

The peptides are synthesized by any of the techniques known in the art, as the method of making them is not critical. One technique is through recombinant methods. Another is manual or automated chemical synthesis using individual amino acids, such as solid phase peptide synthesis. Other methods for synthesizing peptides may be readily apparent to one of ordinary skill in the art

One of ordinary skill in the art would be able to determine through routine experimentation which of the immunoreactive peptides are capable of eliciting opsonic and/or anti-attachment antibodies.

Though it is known generally in the art that even single substitutions may have a great impact on immunogenicity of a molecule, due to allelic variants which exist for any particular GAS serotype, there are expected to be allowable substitutions within the peptides corresponding with each serotype which maintain immunogenicity. As discussed above, the example peptides in Table 1 include allelic variants of the peptides for a given serotype. For example, up to approximately 3 substitutions within each peptide which correspond with variants of a given serotype may create peptides which also are immunoreactive. That a given substitution results in an immunoreactive peptide can be determined by routine experimentation by making a proposed substitution then testing the immunoreactivity by one of many known assays including those described herein. A variant within a serotype can be identified on the basis of sequence. Any variation within 50 N-terminal residues of mature protein of M protein gene type strain is considered a variant. Isolates within an emm type share about .gtoreq.84% deduced amino acid sequence identity [as determined by the Wisconsin Package Version 10.1, Genetics Computer Group (GCG), Madison Wis. FASTA program] within the mature amino terminal 45 amino acids compared to the reference type strain sequence. The first three peptides indicated for each serotype in Table 1 are considered to be the peptides from the majority of isolates of the serotype. The additional peptides given in Table 1 for each serotype in some instances represent the majority of isolates in the type, and in other instances represent known variants of these types.

At least some of the individual peptides are capable of protecting a recipient against its corresponding serotype. A composition comprising a mixture of peptides from more than one serotype is able to protect against those corresponding serotypes. A mixture can be tailored such that it contains the most prevalent serotypes in an area (population), thus making the mixture able to protect against the most important serotypes. The tailoring is accomplished by matching the serotype-specific peptides to epidemiological data regarding the prevalence of the serotypes for the population of recipients desired to be protected.

Though each peptide will be immunoreactive for the serotype upon which it is based, the peptides of the present invention may even provide non-serotype-specific effects. It is believed that it is possible that certain prevalent N-terminal fragments may evoke cross-protective opsonic antibodies. This is demonstrated in Example 5 below. It is expected that the present peptides, compositions or vaccines will evoke cross-type opsonization.

Compositions, Vaccines, and Kits

The invention is also polypeptides, proteins, compositions, or vaccines comprising the peptides or sequences of the peptides. The peptides, in addition to being used individually, can be used as a mixture of peptides. One aspect of the invention is a composition comprising the peptides of the present invention as described above. A composition comprising a mixture of peptides is readily prepared by methods well known in the art. Alternatively, to using the peptides individually or in a mixture, the peptides may be joined together into a polypeptide or protein. One aspect of the invention is a polypeptide comprising the sequences of peptides of the present invention. Another aspect of the invention is a protein comprising the sequences of the peptides of the present invention. Standard techniques known in the art may be used to, for example, link the synthesized peptides, synthesize a polypeptide or protein which contains segments corresponding to the desired synthetic peptides, or link the synthetic peptides to a backbone or a liposome. Examples of backbones include, for example, keyhole limpet hemocyanin, bovine serum albumin, tetanus toxoid, diphtheria toxoid, bacterial outer membrane proteins, and artificial amino acid backbones. It is well known to one of ordinary skill in the art how to covalently bond peptides to a backbone or liposome or how to create polypeptides or proteins using recombinant techniques.

As noted above, a vaccine comprising these synthetic peptides is within the scope of the invention. In one aspect, the vaccine comprises an immunogenic amount of the peptide immunogens of the present invention. The data from a CDC surveillance system showing the epidemiological data, as noted above, showed that the 30 most prevalent invasive M types account for approximately 95% of the total invasive isolates in the U.S. An aspect of the present invention is the development of a multi-antigenic peptide (MAP) vaccine representing these most prevalent serotypes. The peptides of the invention may be conveniently formulated into vaccine compositions comprising one or more of the peptides alone or in association with a pharmaceutically acceptable carrier. See, e.g., Reminigton's Pharmaceutical Sciences, latest edition, by E. W. Martin Mack Pub. Co., Easton, Pa., which discloses typical carriers and conventional methods of preparing pharmaceutical compositions that may be used in conjunction with the preparation of formulations of the inventive peptides and which is incorporated by reference herein. A benefit of the vaccine is it can eliminate over 85% of Group A Streptococci infections and reduce by 85% the nasopharyngeal reservoir of Group A Streptococci in the United States with the correct tailoring. The reservoir of GAS is expected to be reduced for the population, not just an individual. Reduction in GAS would have an effect on carriage of the organism, thereby affecting the reservoir in the population. Reduction in carriage of the organism subsequently reduces the exposure rate, thereby increasing herd immunity.

The vaccine comprises and can be made by providing immunogenic amounts of the peptides alone or in a pharmaceutically acceptable vehicle or carrier. Carriers include water, saline, dextrose, and glycerol, for example. The vaccine can further comprise additional immune-stimulatory molecules, including other GAS immunogens, vaccines of other species (such as H. influenza, pertussis, N. meningitidis, pneumococcus, or Influenzae), and adjuvants or mixture of adjuvants. One of ordinary skill in the art would be able to identify vehicles, carriers, other antigens or immunogens, and immunomodulators, such as adjuvants or cytokines, appropriate for the present invention. Additional additives would also be readily apparent to one of skill in the art, such as wetting agents or preservatives.

A DNA vaccine is also within the scope of the present invention. One aspect of the invention is a DNA vaccine comprising DNA encoding immunoreactive peptides or compositions of the present invention. Methods for making DNA sequences suitable for DNA vaccines are known in the art. One of ordinary skill would be able to determine appropriate promoters or other regulatory sequences which may be used in the DNA construct encoding the immunoreactive compositions. DNA vaccines may further comprise other components as in the vaccines and compositions described above and below, such as carriers and agents which increase levels of immunity, such as liposomes. DNA vaccines may be administered by routes similar to other vaccines. Administration of a DNA vaccine results in expression of antigens which produce a protective immune response.

Though the vaccine of the present invention is expected be most effective with multiple serotype-specific peptides, it could contain from one serotype-specific peptide to multiple serotype-specific peptides for every identified serotype of GAS. One of skill in the art would be able to determine the most cost-effective and clinically therapeutic combination based on epidemiological data, using the tailoring method provided herein. In one aspect of the invention, the vaccine contains at least 3 serotype-specific peptides from 3 different serotypes. For example, a vaccine comprising serotype-specific peptides for emm1, emm3, and emm12 is expected to protect against approximately 38% of invasive GAS disease in the U.S. More specifically, this vaccine can comprise the following peptide combinations from Table 1 -- see Original Patent.

In another aspect of the invention, the vaccine comprises about 10 serotype-specific peptides, each peptide corresponding to one of the 10 most prevalent serotypes in the U.S., thus making it expected to immunize against approximately 65% of GAS disease in the U.S. More specifically, this vaccine can comprise combinations of 10 peptides wherein one peptide comes from each of the M1, M3, M28, M12, M4, M11, M89, st2967, M77/27L, M6 peptides from Table 1. As demonstrated above, the combinations can be generated and tested according the procedures described in this application to determine those which are effective. In a further aspect of the invention, the vaccine comprises about 30 serotype-specific peptides of the 30 most prevalent serotypes, thus making it expected to immunize against approximately 95% of GAS disease in the U.S. More specifically, this vaccine can comprise combinations of 30 peptides wherein one peptide comes from each of the 30 most prevalent serotypes. As demonstrated above, the combinations can be generated and tested according the procedures described in this application to determine those which are effective. In a still further aspect of the invention, the vaccine can comprise at least one serotype-specific peptide from any identified serotype of GAS. A vaccine covering approximately 60% of GAS disease would be expected to be commercially viable. FIG. 1 shows the most prevalent serotypes in the U.S. currently from which the serotype-specific peptides could be chosen to target. Similar data from any targeted population could be used to tailor the vaccine for the prevalent serotypes and a given percentage of disease. This strategy towards a safe and effective vaccine against GAS offers the advantage of being easily modified to fit the needs of a particular region according to the predominant M types located there.

As indicated above, based on the current epidemiological data, similar serotype-specific peptides would be expected to be effective in vaccines or compositions in the U.S., Italy, Mexico and Argentina, for example. The epidemiological data of Malaysia, India, New Guinea, Nepal and Egypt indicate that vaccines or compositions tailored to these areas may require a different subset of GAS serotype-specific peptides. Based on the teaching herein, such a vaccine is easily within the grasp of the skilled person.

Another strategy for designing a vaccine would be to make it selective for specific GAS illnesses, as all GAS do not cause the same illnesses. For example, the most severe GAS diseases are often considered to be necrotizing fasciitis and toxic shock syndrome which are most frequently caused by M1 and M3. Thus, selecting immunogenic molecules specific to these serotypes would tailor the vaccine to this strategy. More specifically, the combinations could be, for example -- see Original Patent.

The peptides, compositions, vaccines or antibodies (discussed below) of the present invention may be administered by any mode of administration capable of delivering a desired dosage to a desired location for a desired biological effect which are known to those of ordinary skill in the art. One of ordinary skill would be able to determine these dosages and routes by routine experimentation. Routes or modes include, for example, orally, parenterally (e.g., intravenously, by intramuscular injection, by intraperitoneal injection), or the like, although subcutaneous administration is preferred. Though the vaccine is envisioned as an injectable, such as subcutaneous or intramuscularly, the vaccine may be formulated in such a way as to render it mucosally deliverable without the peptides being broken down before providing systemic or mucosal immunity, such as, orally, inhalationally, intranasally, or rectally. The amount of active compound administered will, of course, be dependent, for example, on the subject being treated, the subject's weight, the manner of administration and the judgment of the prescribing physician. Immunogenic amounts can be determined by standard procedures. Examples of other peptide vaccines are known in the art. Dosages of the present invention are expected to be in similar ranges.

Depending on the intended mode of administration, the compositions or vaccines may be in the form of solid, semi-solid or liquid dosage forms, such as, for example, tablets, suppositories, pills, capsules, powders, liquids, suspensions, or the like, preferably in unit dosage form suitable for single administration of a precise dosage. The compositions or vaccines may include, as noted above, an effective amount of the selected immunogens in combination with a pharmaceutically acceptable carrier and, in addition, may include other medicinal agents, pharmaceutical agents, carriers, adjuvants, diluents, etc.

A more recently revised approach for parental administration involves use of a slow release or sustained release system, such that a constant level of dosage is maintained. See, e.g., U.S. Pat. No. 3,710,795, which is incorporated by reference herein. A system using slow release or sustained release may be used with oral administration as well. The vaccine or composition may be administered in liposomes, encapsulated, or otherwise protected or formulated for slower or sustained release.

A subject can be inoculated to generate an active immune response to the presence of the immunogenic composition which can later protect the subject from the organism. A passive immune response may be accomplished by any method known in the art.

Kits using peptides or antibodies produced by the present invention may be made. A kit comprises packaging and the antibodies or peptides. A kit may further comprise a solid phase or substrate to which the antibodies or peptides may be attached.

Antibodies

Antibodies are also within the scope of the invention. For example, isolated antibodies which selectively bind with the peptides of the present invention are an aspect of the present invention. These antibodies can be used, for example, in diagnosis, treatment, or vaccination techniques. The antibodies can be monoclonal or specific antibodies. The antibodies can be opsonic antibodies or anti-attachment antibodies. The antibodies are made and isolated by methods well known in the art. Modified antibodies, fragments and humanized antibodies are also within the scope of this invention. It is well known in the art how to make and use modified antibodies, fragments or humanized antibodies.

Methods and Uses

The peptides, compositions, vaccines, and antibodies of the present invention may be used in a variety of applications. For example, preventative/prophylactic, therapeutic, or diagnostic methods; affinity chromatography for separating/purifying antibodies or antigens; active/passive immunotherapy; and use of antibodies generated in passive immunotherapy.

An example of a method of preventing GAS infection comprises administering a prophylactically effective amount of vaccine, or of an anti-idotype antibody to the peptides of the present invention, to a subject. Also, the antibodies against the peptides of the present invention may be administered in a prophylactically effective amount.

An example of a method of treating a GAS infection comprises administering a therapeutically effective amount of antibodies of the present invention to a subject.

An example of a diagnostic method is determining the serotype of GAS organism responsible for an infection by contacting a sample with multiple serotype-specific antibodies of the present invention and determining which of these serotype-specific antibodies are actually bound with the infecting organism. An example of another diagnostic method is contacting a sample with multiple serotype-specific peptides of the present invention and determining which serotype-specific peptides are actually bound with antibodies in the sample.

A method of measuring the amount of GAS organism in a sample comprising contacting a sample with antibodies of the present invention and measuring the amount of immunocomplexes formed.

Affinity chromatography is frequently used for separating and/or purifying antibodies or antigens. By binding the corresponding antibody or antigen to a substrate, a sample can be passed through a column containing the immunoadsorbent and then the column eluted to collect the isolated corresponding antigen or antibody. More specifically, the peptides of the invention can be bound on a column to purify anti-GAS antibodies. Likewise, anti-GAS antibodies generated in accordance with the invention can be bound to a column and used to purify GAS from a sample.

Immunotherapy is another use for the peptides, compositions, vaccines or antibodies of the present invention. As known in the art, active immunotherapy is achieved by activating a subject's own immune system. By administering the peptides, compositions or vaccines of the present invention, an active immune response may be elicited.

As known in the art, passive immunotherapy is achieved by supplementing a subject's immune system with agents such as antibodies. By administering the antibodies of the present invention, a passive immune response may be elicited.

The method for tailoring vaccines comprises a) identifying a population of recipients for the vaccine; b) gathering prevalence data on serotypes of the targeted organism from a sample within that population of recipients; c) choosing a set of the most prevalent serotypes from the gathered data; d) identifying proteins from the chosen serotypes responsible for evading opsonophagocytosis; e) identifying small peptides within the identified proteins which protect for the chosen serotypes; f) synthesizing the identified peptides; g) formulating a vaccine comprising the peptides identified in step e). Specifically, the small peptides may be those of about 20-25 amino acids and protection may be by elicitation of opsonic or anti-attachment antibodies.

Other uses for or variations of the above methods using the above peptides, compositions, vaccines or antibodies may be readily apparent to one of ordinary skill in the art.

The approach of employing a mixture of defined synthetic N terminal M protein segments protecting against prevalent U.S. Group A streptococcal (GAS) strains will favorably compare against any of the prior art approaches. The present approach has found excellent immunogenicity and type-specific opsonic antibody titers with the peptides assessed. Animal studies have indicated that individual peptides protect in a type-specific manner not only against systemic infection, but against nasopharyngeal carriage of GAS. Many N terminal M protein segments have already been demonstrated to not evoke antibodies cross-reactive with human tissues. There is no evidence that chemically linking the current peptides to carriers or backbones will increase the risk of undesirable cross reactions. The methodology can be proven for each of the most common M types found in U.S. invasive disease isolates. The strategy can be expanded to less frequently occurring GAS types. This allows the vaccine to be quickly and precisely adapted to changes in individual strain frequencies in a given geographic area or demographic population by addition or deletion of individual peptide components.
 

Claim 1 of 32 Claims

1. A synthetic peptide consisting essentially of the amino acid sequence of SEQ ID NO:3.
 

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