{"id":158,"date":"2024-05-08T17:18:01","date_gmt":"2024-05-08T17:18:01","guid":{"rendered":"https:\/\/www.merckvaccines.com\/vaqta\/?page_id=158"},"modified":"2026-03-26T09:24:40","modified_gmt":"2026-03-26T09:24:40","slug":"adult-efficacy-immunogenicity","status":"publish","type":"page","link":"https:\/\/www.merckvaccines.com\/vaqta\/adult-efficacy-immunogenicity\/","title":{"rendered":"Efficacy and Immunogenicity \u2013 Adult"},"content":{"rendered":"\n\n
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VAQTA\u00ae (Hepatitis A Vaccine, Inactivated) \u2028Adult clinical data \u2013 efficacy and \u2028immunogenicity<\/strong><\/h1>

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Proven efficacy in adult patients. VAQTA showed:<\/strong><\/h2><\/div>\n\n\n\n
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\"Robust\"Robust<\/figure><\/div>\n<\/div>\n\n\n\n
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\"Sustained\"Sustained<\/figure><\/div>\n<\/div>\n\n\n\n
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Clinical study design<\/strong><\/h3><\/div>\n\n\n\n
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a<\/sup>Immunogenicity data were combined from 5 randomized clinical studies in adults 19 years of age and older who received 2 total doses of VAQTA (50 U\/1-mL) given 6 months apart. These patients had a geometric mean titer (GMT) of 6013 mIU\/mL (95% CI: 5592, 6467) after the second dose. The efficacy of VAQTA in adults 19 years of age and older was based upon immunogenicity measured 4 to 6 weeks following vaccination.

b<\/sup>In another clinical study that evaluated adults who received VAQTA at 0 and 6 months, 99.4% (170\/171) of subjects still had detectable levels of anti-hepatitis A antibodies 6 years later. Six years postvaccination, patients had a GMT of 684 mIU\/mL.

Anti-HAV antibodies \u226510 mIU\/mL indicate seroconversion.<\/p>\n\n\n\n

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Antibody persistence<\/strong><\/h2><\/div>\n\n\n\n
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6-year response demonstrated in adults who received VAQTA<\/strong><\/h3><\/div>\n\n\n\n

In a clinical study, hepatitis A antibody response in adults who were administered 2 doses of VAQTA 6 months apart was shown to persist for at least 6 years.<\/p><\/div><\/div>\n\n\n\n

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\"Detectable\"Detectable<\/figure><\/div>\n\n\n\n
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HAV, hepatitis A virus.

Anti-HAV antibodies \u226510 mIU\/mL indicate seroconversion.

The total duration of the protective effect of VAQTA in healthy vaccinees is unknown at present.<\/p><\/div><\/div>\n\n\n\n

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View Adult Flexible Dosing Schedule<\/a><\/p><\/div><\/div>\n\n\n\n

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aImmunogenicity data were combined from 5 randomized clinical studies in adults 19 years of age and older who received 2 total doses…<\/p>\n","protected":false},"author":709,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_trash_the_other_posts":false,"editor_notices":[],"footnotes":""},"ga4_page_audience":[],"ga4_page_birn_id":[],"ga4_page_branding":[226],"ga4_page_businessunit":[234],"ga4_page_campaign":[],"ga4_page_content_purpose":[275],"ga4_page_customer_journey_stage":[294],"ga4_page_customer_specialty":[348],"ga4_page_experience":[],"ga4_page_indication":[405],"ga4_page_material_intent":[481],"ga4_page_product":[621],"ga4_page_region":[708],"ga4_page_therapeuticarea":[724],"class_list":["post-158","page","type-page","status-publish"],"yoast_head":"\nAdult Efficacy & Immunogenicity With VAQTA\u00ae (Hepatitis A Vaccine, Inactivated)<\/title>\n<meta name=\"description\" content=\"Find 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