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R B Belshe

Publications and source records attributed to R B Belshe.

At least 37 records · Page 2Linked to original sources

Recombinant gp160 as a therapeutic vaccine for HIV-infection: results of a large randomized, controlled trial. European Multinational IMMUNO AIDS Vaccine Study Group.

OBJECTIVES: The primary objective of this study was to expand the safety and immunogenicity database of recombinant gp160 as a therapeutic vaccine in the treatment of HIV-infection. Preliminary efficacy data was also sought. DESIGN: This trial was a randomized, double-blind, placebo-controlled study. Two-hundred and eight volunteers, 96 therapy-naive with CD4 cell count >500x10(6)/l (group A) and 112 with CD4 cell count of 200-500x10(6)/l (group B, 51 out of 112 on treatment with one or two nucleoside analogues), received monthly injections of rgp160 IIIB vaccine or placebo for the first 6 months of the study; booster immunizations with rgp160 MN or placebo were given at times 15, 18, and 21 months. METHODS: Safety and immunogenicity data were obtained and measurements of CD4 cell count, plasma viral RNA, and proviral DNA were performed. Clinical outcome was recorded for the 24 months of study. RESULTS: The vaccine was safe and well tolerated. Despite the induction of new rgp160-specific lymphoproliferative responses and the presence of positive delayed type hypersensitivity skin tests to rgp160 at the end of the 24 month study, no effect on the natural history of HIV infection was detected. Within 24 months, AIDS-defining illnesses had occurred in 19 of the vaccinated volunteers and in 18 of the placebo recipients. Persons with higher plasma viral RNA levels and higher proviral DNA had a more rapid decline in CD4 cell count when compared to persons with lower values. Vaccine did not alter viral RNA or proviral DNA levels. CONCLUSION: There was no clinical benefit to therapeutic immunizations with rgp160, despite the induction of new lymphoproliferative responses.

AIDS Vaccines↗

Effectiveness of live, attenuated intranasal influenza virus vaccine in healthy, working adults: a randomized controlled trial.

CONTEXT: Influenza virus is a major cause of illness, disruption to daily life, and increased use of health care in all age groups. OBJECTIVE: To assess the safety and effectiveness of intranasally administered trivalent, live, attenuated influenza virus (LAIV) vaccine for reducing illness, absenteeism, and health care use among healthy, working adults. DESIGN: Randomized, double-blind, placebo-controlled trial conducted from September 1997 through March 1998. SETTING: Thirteen centers across the United States. PARTICIPANTS: A total of 4561 healthy, working adults aged 18 to 64 years recruited through health insurance plans, at work sites, and from the general population. INTERVENTION: Participants were randomized 2:1 to receive intranasally administered trivalent LAIV vaccine (n = 3041) or placebo (n = 1520) in the fall of 1997. MAIN OUTCOME MEASURES: Episodes of febrile illness, severe febrile illness, febrile upper respiratory tract illness, work loss, and health care use during the peak and total influenza outbreak periods, and adverse events. RESULTS: Recipients of LAIV vaccine were as likely to experience 1 or more febrile illnesses as placebo recipients during peak outbreak periods (13.2% for vaccine vs 14.6% for placebo; P=.19). However, vaccination significantly reduced the numbers of severe febrile illnesses (18.8% reduction; 95% confidence interval [CI], 7.4%-28.8%) and febrile upper respiratory tract illnesses (23.6% reduction; 95% CI, 12.7%-33.2%). Vaccination also led to fewer days of illness across all illness syndromes (22.9% reduction for febrile illnesses; 27.3% reduction for severe febrile illnesses), fewer days of work lost (17.9% reduction for severe febrile illnesses; 28.4% reduction for febrile upper respiratory tract illnesses), and fewer days with health care provider visits (24.8% reduction for severe febrile illnesses; 40.9% reduction for febrile upper respiratory tract illnesses). Use of prescription antibiotics and over-the-counter medications was also reduced across all illness syndromes. Vaccine recipients were more likely to experience runny nose or sore throat during the first 7 days after vaccination, but serious adverse events between the groups were not significantly different. The match between the type A(H3N2) vaccine strain and the predominant circulating virus strain (A/Sydney/05/97[H3N2]) for the 1997-1998 season was poor, suggesting that LAIV provided substantial cross-protection against this variant influenza A virus strain. CONCLUSION: Intranasal trivalent LAIV vaccine was safe and effective in healthy, working adults in a year in which a drifted influenza A virus predominated.

Administration, Intranasal↗

MN and IIIB recombinant glycoprotein 120 vaccine-induced binding antibodies to native envelope glycoprotein of human immunodeficiency virus type 1 primary isolates. National Institute of Allergy and Infectious Disease Aids Vaccine Evaluation Group.

The ability of antibody induced by MN and IIIB recombinant gp120 (rgp120) human immunodeficiency virus type 1 (HIV-1) vaccines to bind to oligomeric native HIV-1 envelope glycoproteins of primary isolates of HIV-1 was measured by flow cytometric indirect immunofluorescence assay (FIFA) in 25 uninfected, healthy adults. After three immunizations, MN rgp120 HIV-1 vaccine given alone and coadministered with IIIB rgp120 HIV-1 vaccine elicited antibody that bound to cells infected with each of a panel of six subtype B strains of HIV-1. Lower levels of vaccine-induced binding antibody were detected against envelope subtype A, D, and (EA) strains of HIV-1 than against subtype B strains. Priming immunization with IIIB rgp120 HIV-1 vaccine alone induced low levels of antibody capable of binding to envelope glycoprotein of primary isolate strains of HIV-1, and booster immunizations with MN rgp120 HIV-1 vaccine resulted in much higher antibody levels. We conclude that MN rgp120 HIV-1 vaccine was an effective inducer of antibody to native envelope glycoproteins of antigenically diverse primary isolates of HIV-1.

AIDS Vaccines↗

HIV-1MN recombinant glycoprotein 160 vaccine-induced cellular and humoral immunity boosted by HIV-1MN recombinant glycoprotein 120 vaccine. National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group.

We evaluated prime-boost immunization with two recombinant envelope glycoprotein subunit vaccines (HIV-1MN recombinant gp160 vaccine in alum adjuvant [MN rgp160] and HIV-1MN recombinant gp120 vaccine in alum adjuvant [MN rgp120]) for safety and immunogenicity in healthy, HIV-1-uninfected adults. The rationale was to combine the helper T cell memory and binding antibody responses typically induced by rgp160 vaccines with the superior neutralizing antibody responses induced by rgp120 vaccines. In a double-blinded, controlled trial, volunteers were randomly assigned to receive MN rgp160 or adjuvant placebo, and a subset later received MN rgp120. The two vaccines were safe, but reactions to MN rgp160 and its adjuvant placebo exceeded those to MN rgp120. MN rgp160 induced IgG binding antibodies, including all IgG subclasses, to MN rgp160 in all vaccine recipients. HIV-1MN-neutralizing and anti-V3 MN peptide-binding antibodies were observed in a majority of volunteers after the fourth MN rgp160 immunization, but at lower levels compared with immunization with MN rgp120 in historical controls. HIV-1-binding, neutralizing, and fusion inhibition antibodies were boosted to the highest levels among MN rgp160 recipients after MN rgp120 booster injections. MN rgp120 boosting appeared to alter the distribution of MN rgp160 vaccine-induced, anti-MN rgp160 IgG subclass antibodies. MN rgp160 induced helper T cell memory, measured by lymphocyte proliferation, Thl and Th2 cytokine production, and skin testing. Strategies including both subunit vaccines may help maximize antibody and helper T cell memory responses to HIV-1 envelope glycoprotein.

AIDS Vaccines↗

A double-blind, placebo-controlled study of Mycobacterium-specific human immune responses induced by intradermal bacille Calmette-Guérin vaccination.

Recent studies have indicated that type 1 T cell responses (potent interferon-gamma and cytolytic responses, with absence of interleukin-4 production) are important for protective immunity against mycobacteria. These observations suggest that assays of type 1 T cell responses may be useful as surrogate markers of protective immunity in the evaluation of new tuberculosis vaccines. To be useful as surrogate markers, immunologic assays must distinguish between vaccine recipients and control subjects in clinical trials. Previous studies have shown that bacille Calmette-Guérin (BCG) vaccination can induce human type 1 T cell responses, but randomized trials have not been done to determine whether measurement of these responses can distinguish between BCG recipients and control subjects. We have conducted a double-blind, placebo-controlled trial of intradermal vaccination with two different BCG strains. We compared the mean lymphoproliferative, cytotoxic, Th1 and Th2 cytokine, and antibody responses detected in BCG and placebo recipients. These studies demonstrated that significant increases in Mycobacterium-specific T cell proliferative responses and type 1 cytokine responses were induced by BCG when compared with results with a placebo. In addition, BCG induced significant increases in Mycobacterium-specific antibody responses with an isotype profile characteristic of a type 1 cytokine bias. T cell and antibody assays involving the use of mycobacterial whole cell lysates or live BCG were able to discriminate between BCG and placebo recipients better than were assays using mycobacterial culture filtrates. These studies provide important information for the development of immunologic assays that might be useful as surrogate markers of protective immunity in future trials of new tuberculosis vaccines.

Adolescent↗

Induction of immune responses to HIV-1 by canarypox virus (ALVAC) HIV-1 and gp120 SF-2 recombinant vaccines in uninfected volunteers. NIAID AIDS Vaccine Evaluation Group.

OBJECTIVE: To determine the ability of live attenuated canarypox virus expressing HIV antigens to induce CD8+ cytotoxic T-cell responses and to prime for neutralizing antibody responses to boosting with purified recombinant gp120 subunit vaccine. DESIGN: A prospective, double-blind, randomized, immunogenicity and safety study was conducted in healthy adults at low risk for acquiring HIV infection and who were seronegative for HIV. METHODS: CD8+ cytotoxic T-cells directed against Env or Gag expressing target cells were measured after live recombinant canarypox-HIV-1 vaccine priming (vaccine given at days 0, 7, 14 and 21). Neutralizing antibodies were measured after subunit boosting (vaccine given at days 28 and 84). RESULTS: CD8+ CTL were induced in 64% of volunteers by the live recombinant canarypox-HIV-1 vaccine. All volunteers who received two doses of subunit vaccine after live recombinant canarypox priming developed neutralizing antibodies directed against laboratory strains of HIV-1 and seven out of eight volunteers tested developed neutralizing antibodies to the primary isolate, BZ167, but to none of eight other primary isolates. Unprimed controls had low or absent neutralizing antibodies after two doses of subunit vaccine. CONCLUSIONS: The live canarypox vector was safe, stimulated cytotoxic T-cells and primed for a vigorous neutralizing antibody response upon boosting with subunit gp120 vaccine. This vaccine combination should be evaluated further for inducing protection against HIV infection.

AIDS Vaccines↗

The efficacy of live attenuated, cold-adapted, trivalent, intranasal influenzavirus vaccine in children.

BACKGROUND: Influenzavirus vaccine is used infrequently in healthy children, even though the rates of influenza in this group are high. We conducted a multicenter, double-blind, placebo-controlled trial of a live attenuated, cold-adapted, trivalent influenzavirus vaccine in children 15 to 71 months old. METHODS: Two hundred eighty-eight children were assigned to receive one dose of vaccine or placebo given by intranasal spray, and 1314 were assigned to receive two doses approximately 60 days apart. The strains included in the vaccine were antigenically equivalent to those in the inactivated influenzavirus vaccine in use at the time. The subjects were monitored with viral cultures for influenza during the subsequent influenza season. A case of influenza was defined as an illness associated with the isolation of wild-type influenzavirus from respiratory secretions. RESULTS: The intranasal vaccine was accepted and well tolerated. Among children who were initially seronegative, antibody titers increased by a factor of four in 61 to 96 percent, depending on the influenza strain. Culture-positive influenza was significantly less common in the vaccine group (14 cases among 1070 subjects) than the placebo group (95 cases among 532 subjects). The vaccine efficacy was 93 percent (95 percent confidence interval, 88 to 96 percent) against culture-confirmed influenza. Both the one-dose regimen (89 percent efficacy) and the two-dose regimen (94 percent efficacy) were efficacious, and the vaccine was efficacious against both strains of influenza circulating in 1996-1997, A(H3N2) and B. The vaccinated children had significantly fewer febrile illnesses, including 30 percent fewer episodes of febrile otitis media (95 percent confidence interval, 18 to 45 percent; P<0.001). CONCLUSIONS: A live attenuated, cold-adapted influenzavirus vaccine was safe, immunogenic, and effective against influenza A(H3N2) and B in healthy children.

Administration, Intranasal↗

Modulation of immunologic responses to HIV-1MN recombinant gp160 vaccine by dose and schedule of administration. National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group.

The safety and immunogenicity of HIV-1MN recombinant gp160 (MN rgp160) vaccine in healthy, uninfected volunteers was tested in a double-blind study with a factorial design. By random assignment, 20 volunteers received three 200 micrograms doses of MN rgp160 and four volunteers received placebo at days 0, 28, and 168 or 0, 56, and 224. Of the 24 volunteers, 16 received 200 micrograms or 800 micrograms of MN rgp160 and two received placebo at day 532 (month 18). The vaccine was safe. It induced T cell memory measured by Th1 cytokine production and lymphocyte proliferation, and serum anti-MN rgp160 IgG (all subclasses) and IgA antibodies. Fifteen of 20 vaccinees developed neutralizing antibody. The regimen including immunizations on days 0, 28, and 168 followed by the 800 micrograms fourth dose was most immunogenic.

AIDS Vaccines↗

Analysis of intercurrent human immunodeficiency virus type 1 infections in phase I and II trials of candidate AIDS vaccines. AIDS Vaccine Evaluation Group, and the Correlates of HIV Immune Protection Group.

Among 2099 uninfected subjects in phase I and II trials of candidate AIDS vaccines, 23 were diagnosed with intercurrent human immunodeficiency virus type 1 (HIV-1) infection. High-risk sexual exposures accounted for 17 infections, and intravenous drug use accounted for 6. Four subjects received placebo, 13 received a complete immunization schedule (> or = 3 injections), and 6 were partially immunized (< or = 2 injections). There was no significant difference between vaccine recipients and control groups in incidence of HIV-1 infection, virus load, CD4 lymphocyte count, or V3 loop amino acid sequence. In summary, 19 vaccinated subjects acquired HIV-1 infection during phase I and II trials, indicating that immunization with the products described is < 100% effective in preventing or rapidly clearing infection. Laboratory analysis suggested that vaccine-induced immune responses did not significantly affect the genotypic or phenotypic characteristics of transmitted virus or the early clinical course of HIV-1 infection.

AIDS Vaccines↗

Induction of immunologic refractoriness in adults by meningococcal C polysaccharide vaccination.

Thirty-four adults were vaccinated with 1/50 of the usual dose of meningococcal polysaccharide vaccine (1 microg of A, C, Y, and W135 polysaccharides, given intramuscularly). This dose was selected as a probe to assess B cell memory. The probe elicited meningococcal C bactericidal antibody responses in all 18 adults who had been vaccinated 4 years earlier with an investigational meningococcal A and C oligosaccharide-protein conjugate vaccine and in the majority of the 11 subjects vaccinated for the first time. In contrast, the responses of the 5 adults given a full dose of licensed polysaccharide vaccine 4 years earlier were <1/10 of those of the other 2 groups. Thus, adults previously given a full dose of meningococcal polysaccharide vaccine show evidence of immunologic refractoriness to group C polysaccharide, whereas refractoriness is not observed after conjugate vaccination. These findings have implications for the use of meningococcal polysaccharide vaccine when the risk of disease is low.

Adult↗

Safety and immunogenicity of low and high doses of trivalent live cold-adapted influenza vaccine administered intranasally as drops or spray to healthy children.

The safety and immunogenicity of various doses of trivalent cold-adapted influenza vaccine (CAIV-T) administered intranasally by drops or spray to children aged 18-71 months was examined. CAIV-T containing A/Johannesburg/33/94 (H3N2), B/Panama/45/90, and A/Texas/36/91 (H1N1) was safe and well-tolerated. At the highest CAIV-T dose, 90%, 50%, and 16% of initially seronegative subjects seroconverted to the H3N2, B, and H1N1 antigens, respectively. The lower immunologic response to the H1N1 vaccine strain compared with the other strains was associated with a low frequency of H1N1 shedding. No statistically significant differences in reactogenicity or immunogenicity were detected between subjects who received CAIV-T by drops or spray. In conclusion, this CAIV-T was safe and induced acceptable immunologic responses to 2 of the 3 vaccine strains. Studies are needed to confirm previous observations that receipt of two doses of this vaccine results in immunologic responses that confer protection to all 3 circulating influenza virus strains.

Administration, Intranasal↗

Advancing AIDSVAX to phase 3. Safety, immunogenicity, and plans for phase 3.

AIDSVAX (VaxGen, Inc., South San Francisco, CA), a possible vaccine to protect against human immunodeficiency virus type 1 (HIV-1) infection, is being tested for efficacy in phase 3 studies. It has been tested for potential efficacy in chimpanzees, and tested for safety and immunogenicity in human clinical studies. Four candidate vaccines, each with a different envelope protein antigen or combination of antigens, have been produced in alum formulations. In both design and clinical testing, AIDSVAX has an excellent safety profile. Because these highly purified proteins were prepared using recombinant DNA technology, there is no possibility of these vaccines causing HIV infection. Having been administered to over 1200 people, the only side effects attributable to AIDSVAX have been local pain and inflammation at the injection site. After immunization, essentially all recipients developed a robust antibody response, including binding and neutralizing antibodies. The neutralizing antibodies peaked after a 12-month boost. Excellent memory is induced. Two phase 3 trials of two bivalent formulations will evaluate their efficacy. One trial will use a bivalent subtype B formulation. This trial in North America will involve 5000 men who have sex with men and heterosexual women at high risk. The other study will use a bivalent subtype B/subtype E formulation. This trial in Thailand and will involve 2500 intravenous drug users. Both studies will be randomized, double-blinded and placebo controlled. The volunteers will be followed for 3 years. The end points of the studies are infection, as defined by seroconversion to standard diagnostic tests, and viral load, as defined by commercial polymerase chain reaction (PCR) tests.

AIDS Vaccines↗

Safety profile of phase I and II preventive HIV type 1 envelope vaccination: experience of the NIAID AIDS Vaccine Evaluation Group.

The NIAID-sponsored AIDS Vaccine Evaluation Group was established in 1988 to perform phase I/II clinical trials with candidate preventive HIV-1 vaccines. This report includes safety data from 1398 HIV-negative, healthy volunteers who were enrolled into 25 phase I and 1 phase H multicentered, randomized, double-blind studies evaluating seven recombinant HIV-1 envelope vaccines, two V3 loop synthetic peptide vaccines, and two live poxvirus-vectored recombinant envelope vaccines. All studies but three were placebo controlled; the placebo was either the adjuvant alone or, in studies of recombinant poxvirus vaccines, it was the vector with no gene insert or a non-HIV gene insert. All candidate vaccines were generally well tolerated. The only adverse effects that were clearly related to vaccination were occasional acute local and systemic reactions that were associated with the adjuvants. Three adjuvants in particular were associated with moderate to severe local reactions: alum plus deoxycholate (ImmunoAg), MTP-PE (Biocine Corp.), and QS21 (Genentech, Inc.). MTP-PE was also associated with self-limited severe systemic reactions. There were no serious adverse laboratory toxicities and no evidence of significant immunosuppressive events after receipt of the candidate vaccines. A few volunteers experienced symptoms that might relate to an underlying immunopathologic mechanism (rash, hemolytic anemia, arthralgia), but their presentations were mild and their incidence was low. Eleven volunteers were diagnosed with malignancies during or after their participation, which was within the 95% confidence interval of the number of cases predicted by the National Cancer Institute SEER (Program for cancer surveillance, epidemiology, and end result reporting) database. In conclusion, the envelope-based recombinant or synthetic candidate HIV-1 vaccines appear to be safe and this work has prepared the way for the testing of increasingly complex candidate HIV-1 vaccines.

AIDS Vaccines↗

A dose-ranging study of a prototype synthetic HIV-1MN V3 branched peptide vaccine. The National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group.

A phase I double-blind trial was done to examine the safety and immunogenicity of a prototype synthetic human immunodeficiency virus type 1 MN strain (HIV-1MN) third variable region domain (V3) branched peptide vaccine in HIV-1-uninfected healthy adult volunteers. Subjects were randomly assigned to receive 20, 100, or 500 micrograms of vaccine or alum adjuvant control on days 0, 28, and 168. The vaccine was well-tolerated and appeared safe. Induction of binding antibody to V3 MN branched peptide was vaccine dose-related and was detectable in 9 of 10 subjects in the highest-vaccine-dose group. HIV-1MN-neutralizing antibody was detected after the third 500-micrograms dose in 8 of 10 subjects at the 90% neutralization end point. V3 MN peptide stimulated lymphocyte proliferation in 15 (75%) of 20 subjects after vaccination. In conclusion, this prototype vaccine was safe and it induced humoral and cell-mediated immune responses.

AIDS Vaccines↗

Immunization with envelope subunit vaccine products elicits neutralizing antibodies against laboratory-adapted but not primary isolates of human immunodeficiency virus type 1. The National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group.

Phase I studies of volunteers not infected with human immunodeficiency virus type 1 (HIV-1) have shown that immunization with envelope subunit vaccine products elicits antibodies that neutralize laboratory-adapted (prototype) HIV-1 strains in vitro. Prototype strains are adapted to grow in continuous (neoplastic) cell lines and are more susceptible to neutralization than are primary isolates cultured in human peripheral blood mononuclear cells. In this study, 50 sera from nine phase I vaccine trials and 16 from HIV-1-infected persons were evaluated for neutralizing antibody activity against 3 laboratory-adapted and 5 primary HIV-1 isolates. Of 50 sera, 49 neutralized at least 1 of the prototype strains; however, none displayed neutralizing activity against primary isolates of HIV-1. Serum from most HIV-1-infected persons neutralized both laboratory-adapted and primary HIV-1 isolates. These data demonstrate a qualitative, or large quantitative, difference in the neutralizing antibody response induced by envelope subunit vaccination and natural HIV-1 infection.

AIDS Vaccines↗

Evaluation of live attenuated influenza vaccines in children 6-18 months of age: safety, immunogenicity, and efficacy. National Institute of Allergy and Infectious Diseases, Vaccine and Treatment Evaluation Program and the Wyeth-Ayerst ca Influenza Vaccine Investigators Group.

Live attenuated, cold-adapted (ca) monovalent and bivalent influenza A vaccines were evaluated in seronegative infants (ages 6-18 months) in a double-blind placebo-controlled trial to assess safety and immunogenicity. A total of 182 seronegative subjects received a single intranasal dose (10(6.2) TCID50) of ca A/Kawasaki/9/86 (H1N1) or ca A/Los Angeles/2/87 (H3N2), both as a bivalent vaccine, or placebo. Respiratory and systemic symptoms did not differ between groups after vaccination. Hemagglutination antibody seroconversions (> or = 1:8) to H3N2 exceeded 90%. In contrast, seroconversions to A/Kawasaki/9/86 (H1N1) were significantly less frequent in bivalent ca vaccine recipients (31%) than in monovalent ca H1N1 recipients (83%) (P < .002). During a subsequent H3N2 epidemic, nasal washes were cultured for viruses from any subject with respiratory illness. H3N2 infections documented by virus isolation were reduced by 65% in ca H3N2 recipients compared with placebo or ca HIM recipients (P = .01).

Adaptation, Physiological↗

Evaluation of a recombinant hemagglutinin expressed in insect cells as an influenza vaccine in young and elderly adults.

Healthy subjects <45 years old (young adults) or >65 (elderly adults) were randomized in double-blind fashion to receive intramuscularly subvirion trivalent influenza vaccine, placebo, or 15, 45, or 135 microgram of the hemagglutinin (HA) of the influenza A/Beijing/32/92 (H3N2) virus expressed in insect cells by a recombinant baculovirus (rHA0). All vaccines were well tolerated. Both young and elderly adults manifested serum hemagglutination-inhibition, virus neutralizing, and HA-specific IgG ELISA antibody responses to rHA0 vaccine. In young adults given 135 microgram of rHA0, the vaccine was significantly more immunogenic than subvirion influenza vaccine. Elderly adults also had increased antibody responses to 135 microgram of rHA0 compared with subvirion vaccine, but the difference was not statistically significant. These results demonstrate that high-dose rHA0 vaccines are well tolerated and effectively induce both functional and binding serum HA-specific antibody in young and elderly adults.

Adolescent↗