Standard immunizations for nonpregnant adults

INTRODUCTION — The immunization schedule for healthy adults, principles behind immunization, and strategies to incorporate these recommendations into practice will be reviewed here.

Recommendations regarding the indications and use of COVID-19 vaccines is discussed in detail elsewhere. (See "COVID-19: Vaccines".)

The rationale and risk-benefit considerations for the administration of each vaccine as well as immunizations for selected groups such as immunocompromised individuals, healthy women who are pregnant or breast feeding, the health care worker, and international travelers are discussed separately.

●(See "Immunizations in solid organ transplant candidates and recipients".)

●(See "Immunizations in hematopoietic cell transplant candidates and recipients".)

●(See "Immunizations in autoimmune inflammatory rheumatic disease in adults".)

●(See "Immunizations during pregnancy".)

●(See "Immunizations for health care providers".)

●(See "Immunizations for travel".)

IMMUNIZATION SCHEDULE FOR NONPREGNANT ADULTS — Immunization recommendations in the United States result from policies developed by the Advisory Committee on Immunization Practices (ACIP) of the United States Centers for Disease Control and Prevention (CDC) (figure 1 and figure 2) [1].

ACIP statements are published in the Morbidity and Mortality Weekly Report and may be obtained from the CDC's Immunization Hotline (1-800-232-2522) or downloaded from the CDC's website. Additional advice can be obtained from the Division of Immunization at the CDC (1-404-639-8225).

PRINCIPLES OF IMMUNIZATION — A number of factors are important when administering vaccines to healthy adults. These issues include the type of immunization to be used, safety, the responsibilities of the individual giving the vaccination, and proper storage.

Type of immunization — Most vaccinations induce active immunity by promoting the development of antibody in the recipient, a response which is expected to be durable. Passive immunization, which usually involves the administration of a globulin product, produces transient immunity for a specific exposure through the transfer of antibody directly.

Active — The goal of active immunization of a vaccine or toxoid is to stimulate the host to produce a primary immune response (usually by inducing B-cell proliferation, antibody response, and T-cell sensitization). If an individual is subsequently exposed to the pathogen against which the vaccine is directed, the exposure results in a secondary response that includes increased proliferation of B cells and formation of antibodies. The secondary response protects the individual from developing disease, ideally for life.

Some vaccines require boosters to sustain protection. Vaccines used for active immunization are derived from whole killed bacteria, live attenuated bacteria or viruses, or antigenic subunits of organisms. Toxoids used for active immunization are bacterial toxins that are modified to render them nontoxic. Toxoids induce the formation of antitoxin antibody. If the host is exposed to the bacterial toxin after immunization, the antitoxin antibody binds to the bacterial toxin, thereby preventing toxin-mediated disease.

Passive — Passive immunization involves administration of antibodies (as intramuscular immune globulin derived from pooled human serum or antitoxin derived from serum harvested from immunized animals). Passive immunization offers short-term protection to people who have been or will be exposed to a specific pathogen and is typically used by immunocompromised patients who are unable to produce an effective immune response with active immunization. Passive immunization is not routinely recommended for healthy adults because the majority of adults are capable of producing a durable immune response through active immunization. Passive immunization is occasionally used for health care workers, pregnant women, and international travelers. (See appropriate topic reviews).

Administration

General principles — The recommended method of storage, preparation, and route of administration of each vaccine is described in the package insert; these instructions must be followed precisely (table 1). Use of doses other than those specified in the package insert is not recommended.

Recommendations regarding practical issues, such as vaccination spacing and timing, injection techniques, and storage and handling, are also available in the Advisory Committee on Immunization Practices (ACIP) guidelines, which are available at the United States Center for Disease Control and Prevention's (CDC's) National Center for Immunization and Respiratory Diseases website [2].

While every effort should be made to adhere to the recommended immunization schedule, it is not necessary to restart the series of any vaccine, even when the interval between doses is prolonged. Subsequent immunizations should continue on the originally recommended immunization schedule.

Technique — Most adult vaccines are administered intramuscularly or subcutaneously, usually in or over the deltoid muscle. Anticoagulation is not a contraindication to vaccination. One study evaluated the safety of influenza vaccine administered either subcutaneously or intramuscularly and found no greater adverse effects, including hemorrhage, with the intramuscular route [3].

Even though vaccination is recommended, the ACIP suggests that a 23-gauge or smaller caliber needle be used for intramuscular vaccination of patients with bleeding disorders or those taking anticoagulants. Firm pressure should be applied to the vaccination site, without rubbing for two minutes [4].

Deltoid intramuscular injections should be administered at the midpoint of the muscle, two to three fingers' width below the acromion process (figure 3). The injection should be administered at a 90° angle; no aspiration is needed. In addition, the correct needle length should be used, which depends on weight and sex. The objective is to inject into the muscle, rather than through it (which can increase risk for bursitis). The CDC recommends needle lengths of 5/8 inch for individuals <60 kg, 1 inch for individuals 60 to 70 kg, 1.0 to 1.5 inch for women 70 to 90 kg and men 70 to 118 kg, and 1.5 inch for women >90 kg and men >118 kg [5].

Subcutaneous injection should be given with a 23 to 25 gauge needle with a needle length of 5/8 to 3/4 inch.

In general, gluteal administration should be avoided for standard immunizations. The immunogenicity of the hepatitis B vaccine is diminished when given in the buttock. (See "Hepatitis B virus immunization in adults".)

Vaccine coadministration — Most vaccines can be administered simultaneously at different sites without compromising efficacy. For adults of all ages, coadministration of the pneumococcal and influenza vaccine appears safe and does not compromise efficacy of either vaccine. In a Finnish study of 9336 individuals ages 65 years and older, the group of 4755 who received simultaneous pneumococcal and influenza vaccines experienced approximately double the number of mild local reactions and fevers compared to the 4581 receiving influenza vaccine alone (441 per 1000 vaccinations versus 284 per 1000 for local reactions and 10 per 1000 versus 24 per 1000 for fever) [6]. (See "Pneumococcal vaccination in adults" and "Seasonal influenza vaccination in adults".)

Limitations of coadministration of vaccines include:

●Live virus vaccines should either be administered on the same day or subsequent immunization with live virus vaccines should be delayed one month to avoid the theoretical concern that the immune response to one or both might be impaired.

●Immune globulins should not be administered along with live virus vaccines because the passively administered antibodies can interfere with the vaccine response (this limitation does not apply to inactivated vaccines or oral polio and yellow fever vaccines).

Recent use of immune globulin — If administration of immune globulin (or blood products containing significant amounts of immune globulin) becomes necessary within 14 days of administration of the measles, mumps, and rubella (MMR) vaccine, either vaccination antibody titers should be checked to ensure that the MMR vaccine was effective or the MMR vaccine should be repeated 3 to 11 months after the initial vaccination [7].

Health care provider responsibilities — The National Childhood Vaccine Injury Act of 1986 requires that health care providers who administer vaccines to adults or children follow vaccine directives, maintain records, and report adverse events.

All providers are expected to provide vaccine information statements (VIS) to their patients prior to administering a vaccine. VIS statements are created by the CDC and can be found at the following link: Current CDC VIS statements.

It is also vital to maintain permanent immunization records that include:

●The type of vaccine and dose

●The site and route of administration

●The date that the vaccine was administered

●The date that the next dose is due

●The manufacturer and lot number

●The name, address, and title of the person administering the vaccine

Safety

General principles — Most vaccines are safe to administer, causing only minor side effects. The more common problem with immunization is the missed opportunity to vaccinate based in part upon public misconceptions about the safety of immunization. Many vaccines and toxoids cause side effects such as fever, local reactions at the site of injection, or even serum sickness-like reactions. These adverse reactions can be caused by the immunogenic moiety in the vaccine or by trace amounts of antibiotics, preservatives, stabilizers, and residual animal proteins [8]. These side effects are not considered true contraindications to vaccination.

Contraindications — True contraindications to vaccination are rare and include severe hypersensitivity reactions, such as anaphylaxis and severe neurologic complications. Administration of live virus vaccines to immunocompromised patients is also contraindicated. Vaccination should be avoided only if true contraindications are present (table 2) [7,9].

The following are NOT contraindications to immunization:

●Current or recent mild illness, with or without low grade fever

●Current or recent antibiotic therapy

●Previous mild to moderate local tenderness, redness, swelling, or fever less than 40.5ºC after any vaccination

●Personal history of allergies, except those listed in the following table (table 2)

●Egg allergy (see "Allergic reactions to vaccines", section on 'Hen's egg')

●Family history of adverse reactions to immunization

Patients on anticoagulation — Anticoagulation is not a contraindication to intramuscular vaccination, and in most cases, no special modifications are needed. Data from intramuscular administration of influenza vaccine suggest that excess bleeding is unlikely [3]. We advise patients on anticoagulation therapy to hold pressure at the injection site following vaccine administration. Patients on a direct oral anticoagulant who are especially concerned about bleeding can time the injection to occur approximately two hours prior the next dose. Patients on warfarin who have poor international normalized ratio (INR) control can confirm the INR is within the desired range prior to vaccination.

Adverse event reporting — Adverse events associated with vaccines should be reported to the United States Department of Health and Human Services using the Vaccine Adverse Events Reporting System (VAERS; http://vaers.hhs.gov/index, 1-800-822-7967).

In the United States, providers are required by law to report certain vaccine-associated adverse events. A table listing these requirements is found at the following link: VAERS Table of reportable events following vaccination.

Serious adverse events following COVID-19 vaccines must also be reported, and such events can be found at the following link: VAERS Reporting requirements for COVID-19 vaccines.

Vaccine manufacturers are also required by US regulation to report to VAERS all adverse events made known to them for any vaccine.

In addition to events that must be reported by law, US providers are encouraged to report any clinically significant or unexpected adverse event for any vaccine, even if it is unclear whether the vaccine caused the event.

INCREASING IMMUNIZATION RATES — There have been marked improvements in immunization rates in adults 65 years and older. The national goals of Healthy People 2020 focus on increasing immunization rates and reducing preventable infectious diseases in adults as well as children. Specific goals directed at adults include increasing coverage of 17 vaccines administered across the life span [10].

Administration of the vaccines included in this topic review is recommended by the Advisory Committee on Immunization Practices (ACIP), the American College of Physicians, the American Academy of Family Physicians, and the American Academy of Pediatrics. Medicare Part B reimburses for both the influenza and pneumococcal vaccine. Despite the institutional support for immunization, vaccine delivery to adults is poor. Barriers to immunization of adults include:

●Missed opportunities during contacts with health care providers in offices, outpatient clinics, and hospitals [11]

●Lack of vaccine delivery systems in the public and private sectors that can reach adults in different settings (eg, the workplace)

●Patient and provider fears about adverse events following vaccination

●Provider concerns about efficacy of individual vaccines

There are limited data on the effectiveness of various strategies to improve adult immunization and many unanswered questions. Possible strategies include the following:

●Age-based strategies – Any encounter with an adult aged 50 and over can be used to review immunization status [7].

●Provider-based strategies – Practice-based tracking systems that identify high-risk adults remind physicians of the need to improve immunization rates as does the use of preventative checklists [12,13]. Health maintenance sheets can be placed at the front of all patient charts and can be used to generate standing orders.

●Hospital-based strategies – Using a standing order (eg, on admission or discharge), rather than requiring a physician's signature, has been successfully used by certain institutions for high-risk patients [14]. High-risk patients can be identified by physicians, nurses, pharmacists, and infection control practitioners or by computerized systems searching for high-risk diagnoses and patient age. By contrast, inclusion of a guideline to administer pneumococcal vaccine prior to discharge as part of a pneumonia clinical pathway in Connecticut did not result in increased vaccination rates among adults [15].

●Community-based programs – Vaccine coverage improves when public health departments specifically promote and offer vaccines [16].

●Immunization as a measure of quality of care – The Infectious Diseases Society of America issued an Executive Summary on Immunization Coverage in the US, which cited the need to promote immunization as an important indicator of health care quality in managed care and other organizations [17].

A meta-analysis of 41 studies on the use of reminders to patients found that immunization rates improved for those reminded in 80 percent of the studies [18]. This was true for all of the different practice settings; telephone reminders were the most effective but also the most costly.

A systematic review by the Task Force on Community Preventive Services evaluated 35 studies on the effectiveness of interventions to improve targeted vaccination coverage for influenza, pneumococcal, and hepatitis B vaccines [19]. Provider reminder systems were the only strategy identified to be effective when implemented alone.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Immunizations in adults" and "Society guideline links: Pertussis" and "Society guideline links: Hepatitis B vaccination".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Vaccines for adults (The Basics)" and "Patient education: What you should know about vaccines (The Basics)" and "Patient education: Vaccines and pregnancy (The Basics)")

●Beyond the Basics topics (see "Patient education: Vaccines for adults (Beyond the Basics)" and "Patient education: Vaccination during pregnancy (Beyond the Basics)")

SUMMARY

●Immunization recommendations from the CDC – Immunization recommendations in the United States are detailed in the figures (figure 1 and figure 2). The recommendations result from policies developed by the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC). (See 'Immunization schedule for nonpregnant adults' above.)

●Immunization rates – Pediatric immunization programs in the United States have been very successful; the majority of preschool children are immunized against targeted diseases and few children die annually of vaccine-preventable diseases. There have also been marked improvements in immunization rates in adults 65 years and older, although the rates are lower than in children. Immunization rates for younger adults at risk for pneumococcus and influenza remain unacceptably low. (See 'Introduction' above.)

A number of strategies have been proposed for improving adult immunization rates, including age-based strategies, provider-based strategies, hospital-based strategies, and community-based programs. (See 'Increasing immunization rates' above.)

●Types of immunization – Most vaccinations induce active immunity by promoting the development of antibody in the recipient, a response which is expected to be durable. Passive immunization, which usually involves the administration of a globulin product, produces transient immunity for a specific exposure through the transfer of antibody directly. (See 'Type of immunization' above.)

●Administration of vaccine – The recommended method of storage, preparation, and route of administration of each vaccine is described in the package insert; these instructions must be followed precisely (table 1). (See 'Administration' above.)

●Reporting of adverse events – Adverse events associated with vaccines should be reported to the United States Department of Health and Human Services using the Vaccine Adverse Events Reporting System (VAERS; http://vaers.hhs.gov/index, 1-800-822-7967). Reportable events are listed above. (See 'Adverse event reporting' above.)

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