Recommended Immunization Schedule for Adults Aged 19 Years or Older, United States, 2018*
Authors: David K. Kim, Laura E. Riley, Paul Hunter
Journal: Annals of Internal Medicine (2018)

Clinical Guidelines6 February 2018Recommended Immunization Schedule for Adults Aged 19 Years or Older, United States, 2018*FREEDavid K. Kim, MD, MA, Laura E. Riley, MD, and Paul Hunter, MD, on behalf of the Advisory Committee on Immunization Practices†David K. Kim, MD, MACenters for Disease Control and Prevention, Atlanta, Georgia (D.K.K., L.E.R., P.H.), Laura E. Riley, MDCenters for Disease Control and Prevention, Atlanta, Georgia (D.K.K., L.E.R., P.H.), and Paul Hunter, MDCenters for Disease Control and Prevention, Atlanta, Georgia (D.K.K., L.E.R., P.H.), on behalf of the Advisory Committee on Immunization Practices†Author, Article, and Disclosure Informationhttps://doi.org/10.7326/M17-3439 Eligible for CME Point-of-Care SectionsSupplemental MaterialAboutVisual AbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail This article has been corrected. The original version (PDF) is appended to this article as a Supplement.In October 2017, the Advisory Committee on Immunization Practices (ACIP) voted to approve the Recommended Immunization Schedule for Adults Aged 19 Years or Older, United States, 2018. The 2018 adult immunization schedule summarizes ACIP recommendations in 2 figures and a table of contraindications and precautions for vaccines recommended for adults (Figure). They can be found at www.cdc.gov/vaccines/schedules. The full ACIP recommendations for each vaccine is available at www.cdc.gov/vaccines/hcp/acip-recs/index.html. The 2018 adult immunization schedule has also been approved by the American College of Physicians, the American Academy of Family Physicians, the American College of Obstetricians and Gynecologists, and the American College of Nurse-Midwives. The ACIP-recommended use of each vaccine is developed after in-depth reviews of vaccine-related data, including disease epidemiology, vaccine efficacy and effectiveness, vaccine safety, feasibility of program implementation, and economic aspects of immunization policy (1). The purpose of the adult immunization schedule is to assist health care providers in implementing the current ACIP recommendations for vaccinating adults. Recommended Immunization Schedule for Adults Aged 19 Years or Older, United States, 2018. Recommended Immunization Schedule for Adults Aged 19 Years or Older, United States, 2018. Download figure Download PowerPoint In addition to the figures that display vaccination recommendations based on age and medical conditions and other indications and a Table of contraindications and precautions for vaccinations, the adult immunization schedule contains information on general principles on immunization for adults; considerations for special populations, such as pregnant women; reference resources pertinent to adult immunization; instructions for reporting adverse events and suspected cases of reportable vaccine-preventable diseases; and an ACIP-approved list of standardized abbreviations for vaccines recommended for adults. The 2 figures in the adult immunization schedule are accompanied by footnotes that should be reviewed with Figures 1 and 2. These footnotes provide important details on vaccination recommendations, such as the number of doses in a vaccination series and dosing intervals. Changes in the 2018 adult immunization schedule from the previous year's schedule include new ACIP recommendations on the use of recombinant zoster vaccine (RZV) for adults aged 50 years or older and the use of an additional dose of measles, mumps, and rubella vaccine (MMR) in a mumps outbreak setting. Table. Table. Contraindications and precautions for vaccines recommended for adults aged 19 years or older Download figure Download PowerPoint Figure 1. Recommended immunization schedule for adults aged 19 years or older, by age group, United States, 2018. Download figure Download PowerPoint Figure 2. Recommended immunization schedule for adults aged 19 years or older, by medical condition and other indications, United States, 2018. Download figure Download PowerPoint Footnotes. Footnotes. Download figure Download PowerPoint Footnotes. Footnotes. Continued Download figure Download PowerPoint Zoster vaccination (2). On 20 October 2017, the U.S. Food and Drug Administration approved the use of RZV (Shingrix, GlaxoSmithKline) for adults aged 50 years or older for the prevention of herpes zoster (shingles) and its complications. On 25 October, the ACIP recommended the use of 1) RZV among immunocompetent adults aged 50 years or older for the prevention of herpes zoster and related complications, 2) RZV among adults aged 50 years or older who previously received the zoster vaccine live (ZVL) (Zostavax, Merck & Co.), and 3) either RZV or ZVL for adults aged 60 years or older (RZV is preferred). On 26 October, the ACIP recommended the following in the 2018 adult immunization schedule:• Administer 2 doses of RZV 2–6 months apart to adults aged 50 years or older regardless of past episode of herpes zoster or receipt of ZVL.• Administer 2 doses of RZV 2–6 months apart to adults who previously received ZVL at least 2 months after ZVL.• For adults aged 60 years or older, administer either RZV or ZVL (RZV is preferred).The clinical trials for RZV excluded pregnancy and confirmed or suspected immunocompromising conditions that can result from disease, such as malignancy and HIV infection, or therapy, such as cancer chemotherapy and treatment for autoimmune disorders (3–6). Therefore, there is currently no ACIP recommendation on the use of RZV among pregnant women (health care providers should consider delaying administration of RZV for pregnant women) or adults with immunocompromising conditions, including HIV infection (additional discussions and recommendations by the ACIP on the use of RZV in adults with immunocompromising conditions are pending).Consistent with the existing recommended use of ZVL, the ACIP recommended RZV for adults who are receiving low-dose immunosuppressive therapy, are anticipating immunosuppression, or have recovered from an immunocompromising illness (7). Additionally, as the clinical trials for RZV did not exclude adults with non-immunocompromising chronic health conditions (3–6), and given the safety and effectiveness profiles of other conjugate vaccines recommended for adults, such as hepatitis B and pneumococcal vaccines, the ACIP recommended that RZV should routinely be used for adults with diabetes mellitus; chronic heart, lung, liver, or kidney disease; functional or anatomical asplenia; or complement deficiencies who meet the age criterion.Note that ZVL is contraindicated for pregnant women and adults with severe primary or acquired immunodeficiency, including those with HIV infection and a CD4 cell count <200 cells/µL (there is no recommendation for ZVL for adults with HIV infection and a CD4 cell count ≥200 cells/µL).MMR vaccination (8). On 25 October, the ACIP updated MMR vaccination recommendations to include the use of a third dose of a mumps-containing vaccine for persons previously vaccinated with 2 doses of a mumps-containing vaccine who are identified to by public health authorities as being a part of a group or population at risk for acquiring mumps because of an outbreak. For implementation purposes, the recommendation is that, during a mumps outbreak, persons identified as being at increased risk and who have received ≤2 doses of mumps virus–containing vaccine or have unknown vaccination status should receive 1 dose of MMR. This change is described in the 2018 adult immunization schedule as:• Administer 1 dose of MMR to adults who previously received ≤2 doses of mumps-containing vaccine and are identified by a public health authority to be at increased risk during a mumps outbreak.Adults without evidence of immunity to mumps (defined as: born before 1957, have documented receipt of MMR, or have laboratory evidence of immunity or disease) are routinely recommended to receive 1 dose of MMR for mumps prevention unless they are students in postsecondary educational institutions, international travelers, or household contacts of immunocompromised persons, in which case they should receive 2 doses of MMR at least 28 days apart. In a mumps outbreak setting, those adults identified by a public health authority to be at risk should receive 1 dose of MMR regardless of whether they previously received 0, 1, or 2 doses of a mumps-containing vaccine.Notable changes in the Figures are:• In Figures 1 and 2, "ZVL" replaced the term "HZV" (herpes zoster vaccine) that was used in past adult immunization schedules to refer to the live zoster vaccine. A row for RZV was added above the row for ZVL to distinguish the 2 zoster vaccines and a dashed line was used to separate RZV and ZVL rows to denote that the 2 zoster vaccines are recommended for the same purpose. In the indication bars for RZV, the text that RZV is preferred over ZVL has been added when either RZV or ZVL can be used for adults aged 60 years or older.• In Figures 1 and 2, "Td/Tdap" (tetanus and reduced diphtheria toxoids/tetanus and reduced diphtheria toxoids and acellular pertussis vaccine) has been replaced by "Tdap or Td" and the text in the indication bar has been revised to "1 dose Tdap, then Td booster every 10 years." One dose of Tdap is recommended for adults who have not previously received Tdap as an adult or child (1 dose of Tdap is routinely recommended at age 11–12 years), except for pregnant women who are recommended to receive 1 dose of Tdap for each pregnancy during the early part of gestational weeks 27–36.• In Figures 1 and 2, the text in the indication bar for MenACWY (serogroups A, C, W, and Y meningococcal vaccine) has been revised to "1 or 2 doses depending on indication, then booster every 5 years if risk remains." Adults with functional or anatomical asplenia, persistent complement component deficiencies, or HIV infection should receive 2 doses of MenACWY and revaccinate every 5 years. One dose of MenACWY is recommended for microbiologists who to work with isolates of Neisseria meningitidis and travelers in countries with endemic or epidemic meningococcal disease, and a booster dose of MenACWY is indicated every 5 years if the risk remains. First-year college students living in residence halls and military recruits are also recommended to receive 1 dose of MenACWY. MPSV4 (4-valent meningococcal polysaccharide vaccine) is no longer available and has been removed from the adult immunization schedule.• In Figure 1, the text in the indication bar for MMR has been changed to "1 or 2 doses depending on indication (if born in 1957 or later)." Adults born in 1957 or later who do not have evidence of immunity to measles, mumps, or rubella are routinely recommended to receive 1 dose of MMR. However, students in postsecondary educational institutions, international travelers, and household contacts of immunocompromised persons are routinely recommended to receive 2 doses of MMR at least 28 days apart.• In Figure 1, the text in the indication bars for human papillomavirus (HPV) vaccine for females and males has been revised to "2 or 3 doses depending on age at series initiation." In 2016, the recommended number of doses of HPV vaccine was revised to 2 or 3 depending on the age at which the HPV vaccination series began (9). Before 2016, 3 doses of HPV vaccine was recommended for adolescents and young adults. In 2016, for adolescents and young adults whose HPV vaccination series was initiated before age 15 years, 2 doses of HPV vaccine was recommended. That is, adult females through age 26 years and adult males through age 21 years (and adult males aged 22 through 26 years who may be vaccinated based on individual clinical decision) who received 2 doses of HPV vaccine at least 5 months apart at age 9–14 years are considered fully immunized. Those who received 1 dose of HPV vaccine or 2 doses of HPV vaccine less than 5 months apart at age 9–14 years are recommended to receive 1 additional dose of HPV vaccine at least 5 months after the last dose. Those who previously have not received any HPV vaccine should receive 3 doses at 0, 1-2, and 6 months (minimum intervals: 4 weeks between doses 1 and 2, 12 weeks between doses 2 and 3, and 5 months between doses 1 and 3; repeat doses if they were given too soon). Males and females through age 26 years with immunocompromising conditions, including HIV infection, are recommended to receive 3 doses of HPV vaccine. Men who have sex with men and transgender persons through age 26 years are recommended to receive 2 or 3 doses of HPV vaccine depending on the age at which they started their HPV vaccination series.The (footnotes in the 2018 adult immunization schedule should be read when reviewing Figures 1 and 2. The (footnotes contain additional general information, such as dosing intervals for vaccination series, and considerations for special populations, such as pregnant women and adults with HIV infection. The (footnotes in the adult immunization schedule and the child and adolescent immunization schedule have been harmonized to read more consistently (10).Although modest increases in vaccination coverage rates were observed in several groups of adult population in 2015, the overall vaccination coverage rates for adults in the United States have remained low (11). Among adults, modest increases in influenza vaccination (44.8%, an increase of 1.6 percentage points), Tdap vaccination (23.1%, an increase of 3.1 percentage points), pneumococcal vaccination among adults aged 19–64 years who are at increased risk for pneumococcal disease (23.0%, an increase of 3.3 percentage points), and zoster vaccination among adults aged 60 years or older (30.6%, an increase of 2.7 percentage points) were observed when compared with 2014. Except for the gradual but consistent increase in zoster vaccination among adults aged 60 years or older, no sustained increases in vaccination coverage for adults were seen over several years.In response to the persistently low vaccination coverage rates among adults, the National Vaccine Advisory Committee updated the standards for adult immunization practice to promote the integration of vaccinations as a part of routine clinical care for adults (12). The standards for adult immunization practice is a call to action for health care providers to 1) assess the vaccination status of adult patients at every clinical encounter, 2) strongly recommend needed vaccines to patients, 3) offer vaccines recommended to patients (providers who do not stock vaccines should refer patients to another provider or pharmacist who stocks and administers vaccines), and 4) document vaccines administered in the state or local immunization information system (IIS). The standards for adult immunization practice is the framework with which health care providers are encouraged to implement specific evidence-based strategies to improve the uptake of vaccines by their adult patients, such as designing patient flow to include immunization services, recommending and offering vaccines during the same clinical visit, utilizing standing orders to routinely administer vaccines, and using the IIS to document patient vaccination records and to assess their vaccination status (12).Also known as vaccination registries, IIS are confidential, electronic systems that collect and consolidate vaccination data from vaccination service providers (13). When automated and interoperable with electronic health record (EHR) systems, IIS can lend clinical decision support for the provider, generate reminders for providers, create notifications for patients, generate vaccination data reports for individual patients or groups of patients, help manage vaccine inventories, and other vaccination activities. Immunization programs in all states and municipalities have the authority to collect vaccination records for all age groups ("lifelong IIS"), except Rhode Island and Connecticut, where IIS are limited to vaccination records for children (14). Fifty-five immunization programs in 49 states (the New Hampshire legislature approved the establishment and use of statewide IIS in 2016 and its implementation is pending) and 6 cities (Chicago, District of Columbia, Houston, New York city, Philadelphia, and San Antonio) operate IIS (13). IIS in these state and city immunization programs have matured individually and their capabilities vary. Collectively, they are increasingly becoming important infrastructure for clinical point-of-care and population-level vaccination strategies.Reports submitted by immunization programs estimate that the percentage of adults with 1 or more vaccinations documented in IIS was 25% in 2008, 25% in 2012, and 44% in 2016 (15–17). Note that these percentages reflect a minimum of 1 routinely recommended vaccination documented for adults documented in IIS, far fewer than what they need to be current. In contrast, IIS participation by children younger than 6 years of age with 2 or more vaccinations documented in IIS was 63% in 2006, 86% in 2012, and 94% in 2016 (15, 18).Historically, the primary focus of IIS has been on pediatric populations, particularly with the role of the IIS in supporting Vaccines for Children, a federally funded program that provides vaccines at no cost to children who might not otherwise get vaccinated (19). IIS for children have been successful largely through partnerships with pediatricians and family practitioners who provide "medical homes" for children and routinely use IIS to assess and document pediatric vaccination records. In addition, mandates for vaccinating children, such as vaccination requirements for school entry, compel pediatricians and family practitioners to maintain accurate and current vaccination records for children in IIS. In contrast, adults are vaccinated by multiple health care providers, including specialty care providers, such as obstetricians and cardiologists, in frequently changing "medical homes" due to changes in employment status or health insurance plans, and often in settings outside of health care provider offices or health centers, such as pharmacies, retail clinics, and the workplace. That is, vaccination records for adults are often scattered, incomplete, and difficult to keep up to date. Consolidated adult vaccination records maintained in IIS would, therefore, play an important role in providing point-of-care clinical support for health care providers for adults. Having consolidated vaccination records for adults in IIS necessarily means that health care providers submit adult vaccination records to IIS. In a 2016 survey of approximately 1,300 health care providers whose practices included vaccination services for adults, more than 90% reported routinely assessing their patients for vaccinations, but only 32% reported that their practices submitted adult vaccination records to the IIS in their state or city (Lutz CS, Kim D, Black CL, et al. Implementation of adultimmunization practice standards by US clinicians and pharmacists. In preparation.). In contrast, in a 2013 survey of 627 pediatricians who offered vaccinations to their patients, approximately 90% reported using the IIS in their state or city (20).Health care providers and state and municipal immunization programs increasingly depend on technology to document and maintain updated vaccination records. IIS are an underused tool for primary care providers, including primary care providers; specialty care providers, such as obstetricians and gynecologists; occupational health clinic providers; and pharmacists. The use of IIS is a proven systematic approach that can help health care systems and providers make efficient and effective decisions on vaccinating their adult patients (21, 22). IIS can assist health care providers utilize adult vaccination as a quality measure to report to different payers. For example, health care providers who participate in the Medicare Quality Payment Program's Merit-based Incentive Payment System could use IIS data, such as pneumococcal vaccination records for adults aged 65 years or older, to submit as a quality measure (23). Bidirectional data exchanges between provider EHRs and IIS automate vaccination updates and promote high vaccination coverage. In 2016, IIS in 91% of 49 states and 6 cities received patient vaccination records submitted by health care providers, and 67% received and responded to provider requests for patient vaccination records (18). In addition, IIS can exchange data with health information systems and forecast vaccinations needed by patients that are consistent with ACIP recommendations. Eligible health care providers also have a financial incentive to acquire certified EHR products and demonstrate their meaningful use, defined in part by the Centers for Medicare & Medicaid Services as the data exchange between EHR and IIS (24).There are challenges in the common use of IIS to document vaccinations for adults. First, there are different state regulations regarding consent to retain information in the state or city IIS. Most IIS jurisdictions have the authority to operate an IIS for adults with implied consent and with or without the right to opt out by patients (14). In several IIS jurisdictions, an explicit patient consent is required before adult vaccination information can be submitted to IIS. Second, not all immunization programs have IIS for adults (as mentioned earlier, Rhode Island and Connecticut have IISs for children only). Third, although infrastructure and functional standards describe the operations, data quality, and technology needed by the IIS (9), not all IIS have met all of the functional standards.Multiple factors contribute to low adult vaccination rates. At the individual level, adult patients may not have the awareness or interest in vaccines routinely recommended for adults. Health care providers for adults have a myriad of competing clinical priorities that they feel take precedence over vaccinations and are challenged by coding and billing processes and perceived inadequate payments associated with vaccination services (25–30). At the systems level, health care providers have difficulties ascertaining which vaccines their adult patients need because of incomplete vaccination records, and their EHRs may not be able to systematically assess vaccination records from IISs. Health care systems and providers and immunization programs continue to collaborate to automate bidirectional flow of vaccination data between EHRs and IIS.Plans for IIS include immunization programs continuing to onboard adult vaccination service providers into IIS and automate EHRs to submit and import vaccination data, continuing to develop up-to-date clinical decision-support tools that interface between EHRs and IIS to forecast vaccination needs of adult patients, and sharing adult vaccination data securely and efficiently (13). In addition to developing vaccination procedural coding manuals to help health care providers administer vaccines to their adult patients (31, 33), the American College of Physicians, the American Academy of Family Physicians, and the American College of Obstetricians and Gynecologists, among other organizations, promote the use of IIS to document and manage adult vaccination records. Consistent use of IIS by health care providers will improve clinical and preventive health services delivery and reduce the burden of illnesses, hospitalizations, and mortality associated with vaccine-preventable diseases among adults.AppendixRecommendations for routine use of vaccines in children, adolescents, and adults are developed by the Advisory Committee on Immunization Practices (ACIP). ACIP is chartered as a federal advisory committee to provide expert external advice and guidance to the Director of the Centers for Disease Control and Prevention (CDC) on the use of vaccines and related agents to control vaccine-preventable diseases in the civilian population of the United States. Recommendations for routine use of vaccines in children and adolescents are harmonized to the greatest extent possible with recommendations made by the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG). Recommendations for routine use of vaccines in adults are harmonized with recommendations of AAFP, ACOG, the American College of Physicians (ACP), and the American College of Nurse-Midwives (ACNM). ACIP recommendations adopted by the CDC Director become agency guidelines on the date published in the Morbidity and Mortality Weekly Report (MMWR). Additional information on ACIP is available at www.cdc.gov/vaccines/acip.Members of the ACIPNancy Bennett, MD, MS, University of Rochester, Rochester, New York (Chair); Amanda Cohn, MD, Centers for Disease Control and Prevention, Atlanta, Georgia (Executive Secretary); Robert L. Atmar, MD, Baylor University, Houston, Texas; Edward Belongia, MD, Marshfield Clinic Research Foundation, Marshfield, Wisconsin; Echezona Ezeanolue, MD, MPH, University of Nevada, Las Vegas, Nevada; Paul Hunter, MD, University of Wisconsin, Madison, Wisconsin; Allison Kempe, MD, MPH, University of Colorado, Denver, Colorado; Grace M. Lee, MD, MPH, Lucile Packard Children's Hospital, Stanford, California; Kelly Moore, MD, MPH, Tennessee Department of Health, Nashville, Tennessee; Cynthia Pellegrini, March of Dimes, Washington, DC; Arthur L. Reingold, MD, University of California, Berkeley, California; Laura E. Riley, MD, Harvard University, Cambridge, Massachusetts; José R. Romero, MD, University of Arkansas, Little Rock, Arkansas; David Stephens, MD, Emory University, Atlanta, Georgia; Peter Szilagyi, MD, MPH, University of California, Los Angeles, California; Emmanuel (Chip) Walter Jr., MD, MPH, Duke University, Durham, North Carolina. A list of current ACIP members is available at www.cdc.gov/vaccines/acip/committee/members.html.ACIP Adult Immunization Work GroupWork Group Chair: Laura E. Riley, MD, Cambridge, Massachusetts.Work Group Members: John Epling, MD, MSEd, Syracuse, New York; Sandra Fryhofer, MD, Atlanta, Georgia; Robert H. Hopkins Jr., MD, Little Rock, Arkansas; Paul Hunter, MD, Madison, Wisconsin; Jane Kim, MD, Durham, North Carolina; Laura Pinkston Koenigs, MD, Springfield, Massachusetts; Maria Lanzi, ANP, MPH, Philadelphia, Pennsylvania; Marie-Michele Leger, MPH, PA-C, Alexandria, Virginia; Susan M. Lett, MD, Boston, Massachusetts; Gregory Poland, MD, Rochester, Minnesota; Joni Reynolds, MPH, Denver, Colorado; Charles Rittle, DNP, MPH, RN, Pittsburgh, Pennsylvania; William Schaffner, MD, Nashville, Tennessee; Kenneth Schmader, MD, Durham, North Carolina; Rhoda Sperling, MD, New York, New York; David Weber, MD, MPH, Chapel Hill, North Carolina.Work Group Contributors: Anna Acosta, MD, Atlanta, Georgia; Mitesh Desai, MD, MPH, Atlanta, Georgia; Kathleen Dooling, MD, MPH, Atlanta, Georgia; Lisa Grohskopf, MD, MPH, Atlanta, Georgia; Susan Hairiri, PhD, MPH, Atlanta, Georgia; Lauri Markowitz, MD, Atlanta, Georgia; Sarah Meyer, MD, MPH, Atlanta, Georgia; Sara Oliver, MD, MSPH, Atlanta, Georgia; Tamara Pilishvili, MPH, Atlanta, Georgia; Candice Robinson, MD, MPH, Atlanta, Georgia; Sarah Schillie, MD, Atlanta, Georgia; Raymond A. Strikas, MD, MPH, Atlanta, Georgia; Walter W. Williams, MD, MPH, Atlanta, Georgia.Work Group Consultants: Carolyn Bridges, MD, Boise, Idaho; Tamera Coyne-Beasley, MD, MPH, Chapel Hill, North Carolina; Kathleen Harriman, PhD, MPH, RN, Richmond, California; Molly Howell, MPH, Bismarck, North Dakota; Diane Peterson, Saint Paul, Minnesota; Angela Shen, ScD, MPH, Washington, DC; Litjen Tan, PhD, Chicago, Illinois.Work Group Secretariat: David K. Kim, MD, MA, Atlanta, Georgia.References1. Smith JC. The structure, role, and procedures of the U.S. Advisory Committee on Immunization Practices (ACIP). Vaccine. 2010;28 Suppl 1:A68-75. [PMID: 20413002] doi:10.1016/j.vaccine.2010.02.037 CrossrefMedlineGoogle Scholar2. Advisory Committee on Immunization Practices. Updated 2017 ACIP statement on October 2017 zoster vaccination recommendations. MMWR. [Forthcoming]. Google Scholar3. Lal H, Cunningham AL, Godeaux O, Chlibek R, Diez-Domingo J, Hwang S, et al. Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults. N Engl J Med. 2015;372:2087-96. doi:10.1056/NEJMoa1501184 CrossrefMedlineGoogle Scholar4. Supplement to: Lal H, Cunningham AL, Godeaux O, Chlibek R, Diez-Domingo J, Hwang S, et al. Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults. N Engl J Med. 2015;372:2087-96. Accessed at www.nejm.org/doi/suppl/10.1056/NEJMoa1501184/suppl_file/nejmoa1501184_appendix.pdf on 15 December 2017 Google Scholar5. Cunningham AL, Lal H, Kovac M, Chlibek R, Hwang S, Diez-Domingo J, et al. Efficacy of the herpes zoster subunit vaccine in adults 70 years of age or older. N Engl J Med. 2016;375:1019-32. doi:10.1056/NEJMoa1603800 CrossrefMedlineGoogle Scholar6. Supplement to: Cunningham AL, Lal H, Kovac M, Chlibek R, Hwang S, Diez-Domingo J, et al. Efficacy of the herpes zoster subunit vaccine in adults 70 years of age or older. N Engl J Med 20