**Immunizations Flashcards
Influenza
The Centers for Disease Control and Prevention currently recommends that all persons age ≥6 months be vaccinated annually against influenza regardless of risk factors. Vaccination usually takes place between September and March in the Northern Hemisphere. The trivalent or quadrivalent inactivated virus vaccine is given intramuscularly and is appropriate for all groups, including pregnant women. The intranasal live attenuated vaccine is approved for patients aged 2 to 49 years but should be avoided in pregnant women and in patients with diabetes, immunosuppression, and certain other chronic conditions.
The Advisory Committee on Immunization Practices (ACIP) recommends early antiviral treatment of suspected or confirmed influenza for hospitalized patients; those with severe, complicated, or progressive illness; and those at high risk for influenza complications. Other high-risk medical conditions include cardiovascular disease (except isolated hypertension), active cancer, chronic kidney disease, chronic liver disease, hemoglobinopathies, immunocompromise (including HIV disease), and neurologic diseases that impair handling of respiratory secretions.
When treatment is indicated, it should be started within the first 2 days of symptom onset to reduce the duration of illness and decrease the risk for serious complications. Oseltamivir or zanamivir is indicated for those with influenza A or influenza B virus infection and for those in whom the influenza virus type is unknown.
Amantadine and rimantadine are related antiviral medications in the adamantane class that are active against influenza A viruses but not influenza B viruses. In recent years, widespread adamantane resistance among influenza A strains has been noted. These agents are not recommended for antiviral treatment or chemoprophylaxis for circulating influenza A strains.
Td / Tdap
Current recommendations are that a tetanus and diphtheria (Td) vaccine be routinely administered every 10 years.
Owing to an increased incidence of pertussis, thought in part to be related to waning immunity from childhood vaccination, all adults are recommended to receive a single tetanus, diphtheria, and acellular pertussis (Tdap) vaccination regardless of the interval since their last Td booster (although it may be given in place of a decennial Td booster if scheduled); this is a particularly important recommendation for persons age 65 years or older because of the high burden of associated disease in this patient population. In addition, all postpartum women, health care workers, and adults who have close contact with infants younger than 12 months should receive a one-time Tdap booster if not already given.
Dtap
Diphtheria–tetanus–acellular pertussis immunization
Components
- Diphtheria toxoid
- Tetanus toxoid
- Conjugated pertussis antigen (pertactin)
Schedule
- 5 doses given at ages:
- 2, 4 & 6 months
- 15-18 months
- 4-6 years
Contraindications
- Encephalopathy after previous dose
- Anaphylaxis to vaccine component
The diphtheria–tetanus–acellular pertussis (DTaP) vaccine is a combination vaccine containing acellular pertussis antigen with diphtheria and tetanus toxoids. Combination vaccines are safe, effective at preventing infection, and beneficial in reducing the number of needlesticks required (resulting in decreased pain and improved compliance).
Children should receive 5 doses of the inactivated DTaP vaccine at ages 2, 4, and 6 months; 15-18 months; and 4-6 years.
The risk of an adverse reaction to the DTaP vaccine is low and generally includes minor erythema/swelling at the injection site and/or fever. Seizure, triggered by fever or by the pertussis vaccine component, is rare and is typically short (<5 minutes) and self-limited. Patients with a family history of febrile seizures or epilepsy may be at increased risk. However, neither personal nor family history of seizures is a contraindication to immunization. Specifically, uncomplicated seizure following vaccine administration is not a contraindication to future vaccination. The benefit of DTaP vaccination, especially in the setting of a pertussis outbreak, outweighs the unlikely risk of significant side effects.
Herpes (Varicella) Zoster (Shingles)
The herpes zoster (shingles) vaccine has been available for several years and is currently recommended for adults age 60 years and older to decrease the risk of herpes zoster and postherpetic neuralgia.
The herpes zoster vaccination is currently recommended for adults 60 years of age or older regardless of whether or not they report a prior episode of herpes zoster. The vaccination is not approved for persons younger than the age of 60, though trials are currently underway to assess safety and efficacy in younger age group.
Varicella immunization is recommended for adults who have not had evidence of infection or immunization. US-born people born before 1980 are generally considered immune, with the exception of health care workers and pregnant women. Two doses of vaccine are required, 4 to 8 weeks apart, regardless of a person’s age, unless they have evidence of receiving one vaccine dose in the past. While many people who do not remember having chicken pox have serologic evidence of immunity, testing is not necessary, as the vaccine is well-tolerated in those already immune. While non-immune pregnant women should not receive the vaccine until after delivery, household contacts of immunocompetent pregnant women do not need to delay vaccination. Rarely, people receiving the vaccine may develop infection. This occurs in approximately 1% of people vaccinated. However, the case is mild, and does not appear to be contagious.
PPSV23
Pneumococcal pneumonia is caused by a variety of Streptococcus pneumoniae serotypes. Each infectious serotype produces a distinct capsular polysaccharide, and anti-capsular antibodies formed during an immune response provide immunity against only a single serotype. As such, at-risk patients are given a pneumococcal vaccine containing multiple capsular antigens. Two types of vaccines are currently available for use in the United States:
Pneumococcal polysaccharide vaccine (PPSV23) contains capsular material from 23 serotypes that have historically been responsible for the majority of pneumococcal infections. Because polysaccharides alone cannot be presented to T cells, the vaccine induces a relatively T-cell-independent B-cell response that is less effective in young children and the elderly.
Protects against 60% of bacteremic disease and is associated with substantial reductions in morbidity and mortality among elderly and high-risk adults and is therefore recommended for all adults age ≥65 years and for adults with other risk factors (asthma, diabetes, cirrhosis, asplenia)
PCV13 (prevnar 13)
PCV13 is more antigenic and has been used primarily in patients with significant immunocompromising conditions, such as asplenia, cerebrospinal fluid leaks, or cochlear implants. However, it has been shown that the combination of PPSV23 and PCV13 together provides the most comprehensive protection against pneumococcal disease in patients age 65 years and older. Therefore, dual immunization is recommended, although to achieve maximal immune response, the two vaccines are not administered together.
Pneumococcal conjugate vaccine (PCV13) consists of capsular polysaccharides from 13 of the most common serotypes that have been covalently attached to inactivated diphtheria toxin protein. This polysaccharide-protein conjugate induces a T-cell-dependent B-cell response, resulting in improved immunogenicity due to the formation of higher-affinity antibodies and memory cells.
In patients 65 years or older who have never been vaccinated against pneumococcal pneumonia or who do not know their vaccination status, the vaccines should be administered sequentially with PCV13 given first, followed by the PPSV23 vaccine 6 to 12 months later.
Routine administration of the PCV13 is recommended for all infants and young children. PPSV23 is administered to adults age <65 with predisposing comorbidities (eg, chronic heart or lung disease, diabetes mellitus, cirrhosis). Immunocompromised patients and all individuals age >65 should receive both vaccines to maximize protection.
Sequential vaccination with the 13-valent pneumococcal conjugate vaccine (PCV13) FOLLOWED (at a later time) by the 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for all adults age >65 and for those age <65 with certain very high-risk comorbid conditions (eg, cerebrospinal fluid leaks, sickle cell disease, cochlear implants, congenital or acquired asplenia, immunocompromised patients).
❗ For adults age <65 with other chronic medical conditions that increase the risk of invasive pneumococcal disease (eg, heart or lung disease, diabetes, smoking, chronic liver disease), PPSV23 ALONE is recommended, followed by sequential PCV13 and PPSV23 at age 65
HPV
The quadrivalent HPV vaccination has been shown to be highly immunogenic, safe, and well-tolerated in females aged 9 to 26. To be most effective, the vaccine should be given before a female becomes sexually active. It can be administered when a patient has an abnormal Pap test or when a woman is breast-feeding. It can also be given when a patient is immunocompromised because of a disease or medication. It is not recommended for use during pregnancy. The vaccine was recently approved for use in males aged 9 to 26 to reduce the likelihood of genital warts. As in women, it is most effective if administered before exposure to HPV through sexual contact.
Both vaccines protect against high-risk HPV subtypes (HPV-16 and HPV-18), and the quadrivalent additionally protects against subtypes that cause genital warts (HPV-6 and HPV-11). Either vaccine is recommended for use in women. Both vaccines are administered in three doses: time zero and then 1 to 2 months later, with the third dose being given 6 months after the initial dose. Pregnant women should not receive the vaccine because there is a lack of safety data in this population.
The ACIP also recommends that boys and men age 11 to 21 years receive the quadrivalent vaccine, although the vaccine may be given to boys as young as 9 years of age.
PCV7
All healthy children aged 24 to 59 months who have not completed their primary immunization for PCV7 be given one dose of PCV7. If the child had received less than three doses of the PCV7 during his/her primary immunization series, two doses should be given at least 8 weeks apart. The usual schedule for the series is one vaccination at 2, 4, 6, and 12 to 15 months.
Chlamydia
All sexually active women age younger than 25 years should undergo screening for chlamydial infection.
Any man or woman deemed to have risk behaviors (high-risk sexual encounters, history of a sexually transmitted infection, history of sex work, inconsistent condom use) should be screened for chlamydial infection, syphilis, and gonorrhea.
Rubella
Rubella is normally a mild self-limited illness, but infection during pregnancy can result in fetal death or congenital defects known as congenital rubella syndrome (CRS). CRS is devastating, and rubella immunity is important for women considering pregnancy. If a woman is found to be rubella nonimmune, vaccination should not occur if she is pregnant or planning pregnancy in the next 4 weeks. Although the vaccine is contraindicated in pregnancy, inadvertent vaccination is not an indication for therapeutic abortion. If the patient is currently pregnant and nonimmune, she should be vaccinated as early in the postpartum period as possible.
Hepatitis A
Hepatitis A vaccination is indicated for men who have sex with men or users of injection drugs. Occupational indications include persons working with hepatitis A virus (HAV)-infected primates or with HAV in a research laboratory setting. Medical indications include chronic liver disease and persons that receive clotting factor concentrates.
Hepatitis B
The hepatitis B vaccine is indicated for all children and adolescents through age 18 years, persons with HIV or other recent sexually transmitted infections, persons who are sexually active but not monogamous, workers with occupational exposure to blood, clients and staff of institutions for developmentally disabled individuals, correctional facility inmates, illicit drug users, persons with diabetes mellitus who are younger than 60 years, and persons with advanced chronic kidney disease who are approaching hemodialysis. Hepatitis B vaccination is also indicated for those planning travel to an endemic area and those with an increased risk for morbidity related to the disease, as well as for persons who request vaccination.
If a person were to be hepatitis B surface antibody negative, the immunization schedule would be one injection at time 0, one between 1 and 2 months after that, and a third injection between 4 and 6 months after the second.
HIV
The guidelines recommend that all persons between the ages of 13 and 64 years be screened for HIV infection. This recommendation is based on evidence from several studies that have demonstrated that screening for HIV is effective even in low-prevalence settings. This is particularly true when screening is coupled with the availability of antiretroviral therapy. Recommended screening is with a combination assay detecting serum HIV antibody and p24 antigen. In contrast to the CDC guidelines, the U.S. Preventive Services Task Force (USPSTF) assigns a C grade to HIV screening, making no recommendation for or against routine HIV screening.
Meningococcal vaccination
Meningococcal vaccination
Regular schedule (vaccinate at age 11-18)
- Primary vaccination preferably at age 11-12
- Booster at age 16-21 (if primary vaccination at age <16)
High-risk patients (vaccinate even if age >18)
- Complement deficiency, asplenia
- College students in residential housing (age <21), military recruits
- Travel to endemic area, exposure to community outbreaks
Meningococcal vaccination with a quadrivalent (serotypes A, C, Y, W135) conjugate vaccine is recommended for all adolescents.
In general, a booster vaccine should be provided at age 16 (up to age 21) if the primary vaccine was at age <16.
Meningococcal vaccination is also recommended before travel to highly endemic environments, such as most of sub-Saharan Africa and the Muslim hajj pilgrimage to Mecca, Saudi Arabia.
In addition, an increased risk of meningococcal meningitis is found among young adults in large groups living in close proximity, such as military recruits and first-year college students residing in dormitories (although the details of this patient’s arrangements are unknown).
Primary vaccination can also be given to adults age >18 who are at increased risk for invasive meningococcal disease (eg, complement deficiency, functional or anatomic asplenia).
