Study guide
6.1 ACIP Adult Respiratory Vaccines: Influenza, COVID-19, RSV & Pneumococcal
ABFM Family Medicine Certification Study Guide Exam
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1 Chapter 1: Exam Structure, Blueprint & Clinical Decision-Making
1.1 Exam Blueprint, FMCLA vs. One-Day Exam & Board Scoring 1.2 Clinical Reasoning, Test-Taking Strategy & Ambiguity Management 1.3 Evidence-Based Medicine & Clinical Practice Guidelines in Primary Care
2 Chapter 2: Healthcare Systems, Practice Management & Quality
2.1 Practice Management, Billing, Coding & Documentation 2.2 Quality Improvement, Patient Safety & Diagnostic Stewardship 2.3 Interprofessional Team-Based Care & Care Coordination
3 Chapter 3: Ethics, Law, Biostatistics & Health Equity
3.1 Medical Ethics, Informed Consent & Surrogate Decision-Making 3.2 Biostatistics, Clinical Epidemiology & Diagnostic Test Interpretation 3.3 Social Determinants of Health, Health Equity & Cultural Humility 3.4 Physician Wellness, Burnout Prevention & Professionalism
4 Chapter 4: Lifestyle Counseling & Behavior Change
4.1 Alcohol Use Screening & Brief Intervention 4.2 Illicit Drug & Cannabis Counseling 4.3 Tobacco & Vaping Cessation Counseling
5 Chapter 5: Nutrition, Physical Activity & Chronic Disease Prevention
5.1 Dietary Counseling for Obesity & Chronic Disease Prevention 5.2 Exercise Prescription & Physical Activity Counseling 5.3 Genetic Risk Assessment & Family History Counseling
6 Chapter 6: Routine Adult Immunizations
6.1 ACIP Adult Respiratory Vaccines: Influenza, COVID-19, RSV & Pneumococcal 6.2 ACIP Adult Non-Respiratory Vaccines: Tdap, Shingrix, HPV & Hep B 6.3 Immunizations in Special Populations: Pregnancy, Asplenia & Immunocompromise
7 Chapter 7: Pediatric Health Maintenance & Surveillance
7.1 Newborn Examination & Early Postnatal Care 7.2 Well-Child Care, Developmental Surveillance & Milestones 7.3 Pediatric & Adolescent Screening: Vision, Hearing, Anemia & Lead 7.4 Pediatric Oral Health, Dental Screening & Fluoride
8 Chapter 8: Behavioral Health & Safety Screening
8.1 Primary Care Depression, Anxiety & Behavioral Health Screening 8.2 Domestic Violence, Intimate Partner Violence & Firearm Safety 8.3 Occupational Health & Recreational Safety Counseling
9 Chapter 9: Adult Preventive Screening: Cardiovascular & Metabolic
9.1 Cardiovascular Disease & Hypertension Screening 9.2 Type 2 Diabetes Screening & Prediabetes Risk Stratification 9.3 Abdominal Aortic Aneurysm & Osteoporosis Screening
10 Chapter 10: Adult Cancer Screening: Breast & Gynecologic
10.1 Breast Cancer Screening & Risk-Assessment 10.2 Cervical Cancer Screening & ASCCP Algorithms 10.3 Skin Cancer Clinical Assessment & Counseling
11 Chapter 11: Adult Cancer Screening: Colorectal, Lung & Prostate
11.1 Colorectal Cancer Screening Modalities & Intervals 11.2 Lung Cancer Screening with Low-Dose CT 11.3 Prostate Cancer Screening & Shared Decision-Making
12 Chapter 12: Sexual Health, Infectious Disease Screening & Contraception
12.1 Sexual Health Counseling & Risk-Reduction Strategies 12.2 STI Screening: Chlamydia, Gonorrhea, Syphilis & Trichomoniasis 12.3 Bloodborne Infectious Disease Screening: HIV & Hepatitis C
13 Chapter 13: Reproductive Life Planning, Lactation & Preoperative Care
13.1 Preconception Planning & Comprehensive Contraception Management 13.2 Lactation Support & Breastfeeding Counseling 13.3 Preoperative Medical Evaluation & Pre-Participation Sports Exam
14 Chapter 14: Emergent Cardiovascular Conditions
14.1 Acute Coronary Syndromes & Myocardial Infarction 14.2 Acute Chest Pain Risk Stratification & Triage 14.3 Acute or Critical Valvular Heart Emergencies
15 Chapter 15: Cardiac Arrhythmias, Heart Failure & Hypertensive Crises
15.1 Acute Atrial & Ventricular Arrhythmias 15.2 Acute Decompensated Heart Failure & Cardiogenic Shock 15.3 Hypertensive Emergency & Urgency Management
16 Chapter 16: Vascular & Thromboembolic Emergencies
16.1 Pulmonary Embolism & Deep Vein Thrombosis 16.2 Acute Aortic Syndromes & Peripheral Vascular Emergencies 16.3 Critical Limb Ischemia & Acute Arterial Occlusion
17 Chapter 17: Neurologic Emergencies: Stroke & Altered Consciousness
17.1 Acute Ischemic Stroke & Intracranial Hemorrhage 17.2 Syncope Evaluation & Status Epilepticus 17.3 Acute Delirium, Encephalopathy & Severe Confusion
18 Chapter 18: Neurologic Trauma & Acute Cranial Emergencies
18.1 Concussion, Moderate-to-Severe TBI & Intracranial Injury 18.2 Thunderclap & Acute Severe Secondary Headaches 18.3 Acute Ophthalmologic Emergencies
19 Chapter 19: Acute Abdominal, Pelvic & Gastrointestinal Emergencies
19.1 Acute Abdominal & Pelvic Pain Triage 19.2 Upper & Lower Gastrointestinal Bleeding 19.3 Acute Hepatic Failure, Cholangitis & Severe Jaundice
20 Chapter 20: Acute Pulmonary & Airway Emergencies
20.1 Acute Hypoxic Respiratory Failure & ARDS 20.2 Severe Community-Acquired Pneumonia & Empyema 20.3 Acute Severe Epistaxis & Airway Obstruction
21 Chapter 21: Acute Traumatic Injuries & Wound Care
21.1 Major Trauma Resuscitation & Initial Assessment 21.2 Burn Assessment, Inhalation Injury & Resuscitation 21.3 Laceration Management, Complex Wounds & Animal Bites
22 Chapter 22: Acute Orthopedic & Musculoskeletal Emergencies
22.1 Acute Ambulatory Fractures & Initial Splinting 22.2 Compartment Syndrome & Major Orthopedic Trauma 22.3 Septic Arthritis & Acute Microcrystalline Crises
23 Chapter 23: Severe Infections, Sepsis & Systemic Emergencies
23.1 Sepsis, Septic Shock & Initial Fluid Resuscitation 23.2 Necrotizing Soft Tissue Infections & Severe CNS Infections 23.3 Anaphylaxis Diagnosis, Epinephrine Dosing & Airway Protection
24 Chapter 24: Metabolic, Endocrine & Electrolyte Emergencies
24.1 Diabetic Ketoacidosis & Hyperosmolar Hyperglycemic State 24.2 Critical Electrolyte Emergencies: Dyskalemias & Dysnatremias 24.3 Severe Calcium Abnormalities & Acute Adrenal Crisis
25 Chapter 25: Hematologic, Urologic & Dental Emergencies
25.1 Severe Symptomatic Anemias & Coagulopathic Emergencies 25.2 Testicular Torsion, Priapism & Acute Urinary Retention 25.3 Urgent Odontogenic Infections & Dental Trauma
26 Chapter 26: Psychiatric, Behavioral & Obstetric/Gynecologic Emergencies
26.1 Suicidal Ideation, Acute Agitation & Behavioral Emergencies 26.2 Acute Physical & Sexual Assault Care 26.3 Life-Threatening Vaginal Bleeding & Ectopic Pregnancy 26.4 Environmental Heat Stroke & Severe Hypothermia
27 Chapter 27: Acute Head, Neck & Neurologic Symptoms
27.1 Primary Acute Headaches: Migraine, Tension & Cluster 27.2 Concussion & Minor Closed Head Injury Evaluation 27.3 Transient Ischemic Attack Evaluation & ABCD2 Risk Scoring
28 Chapter 28: Acute Cranial Nerves, Hearing & Sensory Symptoms
28.1 Peripheral Neuropathies: Bell's Palsy, Carpal Tunnel & Radiculopathy 28.2 Acute Tinnitus, Sudden Sensorineural Hearing Loss & Cerumen Impaction 28.3 Acute Dizziness, Benign Paroxysmal Positional Vertigo & Vestibular Neuritis
29 Chapter 29: Acute Upper Respiratory Tract Infections
29.1 Acute Viral Rhinosinusitis vs. Bacterial Rhinosinusitis 29.2 Acute Pharyngitis: Group A Streptococcus & Centor Criteria 29.3 Acute Otitis Media, Otitis Externa & Serous Effusion
30 Chapter 30: Acute Lower Respiratory Infections & Cough
30.1 Influenza, COVID-19 & Viral Respiratory Syndromes 30.2 Acute Bronchitis & Lower Respiratory Tract Infections 30.3 Ambulatory Community-Acquired Pneumonia
31 Chapter 31: Allergic, Nasal & Non-Infectious Pulmonary Conditions
31.1 Allergic Rhinitis & Acute Non-Anaphylactic Allergic Reactions 31.2 Acute Dyspnea in Ambulatory Care 31.3 Interstitial Lung Diseases & Sarcoidosis Presentation
32 Chapter 32: Acute Chest, Cardiac & Vascular Symptoms
32.1 Palpitations Evaluation & Arrhythmia Triage in Primary Care 32.2 Deep Vein Thrombosis & Superficial Thrombophlebitis 32.3 Ambulatory Hypotension & Orthostasis Evaluation
33 Chapter 33: Acute Upper Gastrointestinal Conditions
33.1 Peptic Ulcer Disease & Gastritis 33.2 Dysphagia, Esophagitis & Acute Esophageal Disorders 33.3 Acute Nausea, Vomiting & Foodborne Illness
34 Chapter 34: Acute Lower Gastrointestinal Conditions
34.1 Acute Infectious Diarrhea & Gastroenteritis 34.2 Acute Constipation & Functional Bowel Changes 34.3 Ano-Rectal Disorders: Hemorrhoids, Fissures, Abscesses & Pruritus Ani
35 Chapter 35: Inflammatory, Functional & Malabsorptive GI Disorders
35.1 Acute Flares of Inflammatory Bowel Disease 35.2 Irritable Bowel Syndrome: Diagnosis, Subtyping & Management 35.3 Celiac Disease & Malabsorption Syndromes
36 Chapter 36: Acute Abdominal, Hepatic & Biliary Disorders
36.1 Ambulatory Abdominal & Pelvic Pain Triage 36.2 Acute Cholecystitis, Biliary Colic & Pancreatitis 36.3 Acute Liver Injury & Viral Hepatitis
37 Chapter 37: Acute Abdominal Wall, Hernias & Dental Conditions
37.1 Abdominal Wall, Inguinal & Ventral Hernias 37.2 Acute Dental Pain, Odontogenic Abscess & Aphthous Ulcers 37.3 Acute Edema: Unilateral vs. Bilateral Diagnostic Evaluation
38 Chapter 38: Acute Infectious Dermatoses
38.1 Bacterial Skin Infections: Impetigo, Cellulitis & Cutaneous Abscesses 38.2 Fungal Skin Infections: Tinea Corporis, Cruris, Pedis & Onychomycosis 38.3 Viral Cutaneous Infections: Herpes Simplex, Zoster & Molluscum Contagiosum
39 Chapter 39: Inflammatory, Allergic & Autoimmune Dermatoses
39.1 Atopic Dermatitis, Contact Dermatitis & Eczematous Flares 39.2 Non-Infectious Rashes: Urticaria, Drug Eruptions & Erythema Multiforme 39.3 Cutaneous Malignancies & Premalignant Lesions: AK, BCC, SCC & Melanoma
40 Chapter 40: Acute Shoulder, Elbow & Upper Extremity Injuries
40.1 Rotator Cuff Pathology, Tendinopathy & Shoulder Impingement 40.2 Lateral & Medial Epicondylitis, Olecranon Bursitis & Elbow Sprains 40.3 Wrist & Hand Soft-Tissue Injuries: De Quervain, TFCC & Finger Sprains
41 Chapter 41: Acute Knee, Ankle & Lower Extremity Injuries
41.1 Meniscal Tears, Ligamentous Knee Injuries & Patellofemoral Pain 41.2 Ankle Sprains, Ottawa Ankle Rules & Achilles Tendinopathy 41.3 Plantar Fasciitis, Shin Splints & Overuse Syndromes
42 Chapter 42: Acute Ambulatory Fractures & Dislocations
42.1 Distal Radius, Scaphoid & Common Upper Extremity Fractures 42.2 Metatarsal, Clavicle & Common Lower Extremity Fractures 42.3 Joint Dislocation Management: Nursemaid's Elbow & Shoulder Subluxation
43 Chapter 43: Acute Axial Musculoskeletal Pain & Falls
43.1 Acute Low Back Pain: Red Flags, Strain & Disc Herniation 43.2 Acute Cervical Strain, Whiplash & Axial Neck Pain 43.3 Evaluation of Falls in Ambulatory & Older Patients
44 Chapter 44: Acute Inflammatory Arthropathies & Generalized Pain
44.1 Acute Inflammatory Arthritis & Spondyloarthropathies 44.2 Myalgias, Rhabdomyolysis & Post-Viral Pain Syndromes 44.3 Acute Non-Headache Pain Management Strategies
45 Chapter 45: Acute Renal, Urinary & Genitourinary Conditions
45.1 Uncomplicated UTI, Pyelonephritis & Acute Urethritis 45.2 Hematuria Workup & Glomerulonephritis 45.3 Nephrolithiasis & Acute Urinary Tract Obstruction
46 Chapter 46: Acute Male Genitourinary & Prostatic Conditions
46.1 Acute Prostatitis, Epididymitis & Orchitis 46.2 Acute Scrotal Pain: Torsion vs Appendage, BPH & Male Genital Emergencies 46.3 Acute Urinary Retention & Incontinence Evaluation
47 Chapter 47: Acute Women's Health & Early Pregnancy Care
47.1 Early Pregnancy Diagnosis, Dating & Initial Complications 47.2 Abnormal Uterine Bleeding & Acute Menstrual Disorders 47.3 Premenstrual Syndrome & Premenstrual Dysphoric Disorder
48 Chapter 48: Breast Disorders, STIs & Pediatric Elimination
48.1 Palpable Breast Mass, Mastitis & Nipple Discharge 48.2 Sexually Transmitted Infections: Diagnosis, Staging & CDC Guidelines 48.3 Pediatric Enuresis & Encopresis
49 Chapter 49: Systemic Signs, Metabolic Dysregulation & Miscellaneous Infections
49.1 Acute Fever, Sepsis Screening & FUO in Primary Care 49.2 Acute Hyperglycemia & Symptomatic Hypoglycemia 49.3 Electrolyte Abnormalities: Mild-to-Moderate Disturbances 49.4 Vector-Borne, Tick-Borne & Rickettsial Illnesses
50 Chapter 50: Chronic Cardiovascular Diseases: Hypertension & Ischemia
50.1 Essential Hypertension Management: 2025 AHA/ACC Guideline & JNC Strategies 50.2 Chronic Coronary Artery Disease & Post-MI Secondary Prevention 50.3 Chronic Heart Failure: HFrEF, HFpEF & Quadruple GDMT
51 Chapter 51: Chronic Vascular, Valvular & Dyslipidemic Diseases
51.1 Peripheral Arterial Disease & Claudication 51.2 Chronic Valvular Heart Disease & Murmur Evaluation 51.3 Lipid Disorders & ASCVD Risk-Based Statin Therapy
52 Chapter 52: Chronic Respiratory Diseases: Asthma & COPD
52.1 Chronic Asthma Management: GINA Stepwise SMART Therapy 52.2 Chronic Obstructive Pulmonary Disease: GOLD Recommendations 52.3 Solitary Pulmonary Nodule Evaluation & Fleischner Society Criteria
53 Chapter 53: Chronic Metabolic Diseases: Diabetes Mellitus
53.1 Type 2 Diabetes Management: ADA Pharmacotherapy Algorithms 53.2 Type 1 Diabetes: Basal-Bolus Insulin, CGMs & Diabetic Complications 53.3 Diabetic Microvascular & Macrovascular Disease Surveillance
54 Chapter 54: Obesity, Nutrition & Metabolic Bone Diseases
54.1 Medical & Behavioral Management of Obesity & Incretin Mimetics 54.2 Osteoporosis & Metabolic Bone Disease: DEXA, FRAX & Antiresorptives 54.3 Nutritional Deficiencies: Vitamin D, B12, Iron & Malnutrition
55 Chapter 55: Chronic Endocrine Disorders
55.1 Primary & Subclinical Hypothyroidism, Hyperthyroidism & Nodules 55.2 Adrenal Disorders: Addison's Disease & Cushing's Syndrome 55.3 Hypercalcemia, Hyperparathyroidism & Pituitary Disorders
56 Chapter 56: Chronic Kidney Disease & Venous Disorders
56.1 Chronic Kidney Disease: KDIGO Staging & Renoprotective Therapy 56.2 Chronic Venous Insufficiency, Stasis Dermatitis & Lymphedema 56.3 Chronic Electrolyte & Acid-Base Management in CKD
57 Chapter 57: Chronic Gastrointestinal & Hepatic Diseases
57.1 Gastroesophageal Reflux Disease, Barrett's Esophagus & Dyspepsia 57.2 Chronic Liver Disease: MASLD/NAFLD, Cirrhosis & Portal Hypertension 57.3 Viral Hepatitis B & C: Long-Term Monitoring & DAA Therapy
58 Chapter 58: Colorectal Surveillance & Chronic Pancreaticobiliary Care
58.1 Post-Polypectomy Colorectal Polyp Surveillance Guidelines 58.2 Chronic Pancreatitis & Exocrine Pancreatic Insufficiency 58.3 Chronic Nausea, Gastroparesis & Functional GI Disorders
59 Chapter 59: Chronic Musculoskeletal & Rheumatologic Disorders
59.1 Osteoarthritis: Hip, Knee & Hand Management 59.2 Spinal Conditions: Spinal Stenosis, Spondylolisthesis & Compression Fractures 59.3 Chronic Myopathies & Fibromyalgia Syndrome
60 Chapter 60: Chronic Neurologic & Neurodegenerative Disorders
60.1 Dementia: Alzheimer's, Vascular & Lewy Body Disease 60.2 Parkinson's Disease & Essential Tremor 60.3 Epilepsy: Chronic Antiseizure Medications & Post-Stroke Care
61 Chapter 61: Chronic Peripheral Nerves, Pain & Sensory Disorders
61.1 Diabetic & Chronic Peripheral Neuropathies 61.2 Chronic Pain Syndromes & Chronic Daily Headaches 61.3 Chronic Tinnitus, Presbycusis & Persistent Dizziness
62 Chapter 62: Chronic Psychiatric Disorders
62.1 Major Depressive Disorder & Generalized Anxiety Disorder 62.2 Bipolar Disorder: Maintenance Pharmacotherapy & Lithium Monitoring 62.3 Adult & Pediatric Attention-Deficit/Hyperactivity Disorder
63 Chapter 63: Chronic Behavioral Health & Neurodevelopmental Conditions
63.1 Chronic Behavioral Conditions: PTSD, OCD & Somatization 63.2 Autism Spectrum Disorder & Intellectual Disabilities 63.3 Eating Disorders: Anorexia Nervosa, Bulimia & Binge Eating
64 Chapter 64: Chronic Substance Use Disorders & Tobacco Cessation
64.1 Alcohol Use Disorder: Pharmacotherapy & Relapse Prevention 64.2 Opioid & Stimulant Use Disorders: MOUD & Harm Reduction 64.3 Longitudinal Tobacco Cessation Pharmacotherapy
65 Chapter 65: Chronic Dermatologic Conditions
65.1 Acne Vulgaris, Rosacea & Seborrheic Dermatitis 65.2 Chronic Plaque Psoriasis & Biologic Therapies 65.3 Chronic Eczema, Hidradenitis Suppurativa & Cutaneous Lupus
66 Chapter 66: Chronic Reproductive, Infectious & Geriatric Special Care
66.1 Chronic Menstrual Disorders, Infertility & Sexual Dysfunction 66.2 Menopause Management & Hormone Replacement Therapy 66.3 Chronic HIV Infection Management & Primary Care Integration 66.4 Gender-Affirming Primary Care & Hormone Therapy 66.5 Advance Care Planning, Palliative Care & End-of-Life Symptom Control
67 Chapter 67: Continuity Care: Sleep, Fatigue, Cancer, Pregnancy & the Adult Preventive Visit
67.1 Chronic Insomnia & Obstructive Sleep Apnea 67.2 Chronic Malaise, Fatigue & ME/CFS 67.3 Primary Care During Cancer Treatment & Survivorship 67.4 Routine Prenatal Care & Longitudinal Pregnancy Management 67.5 The Periodic Adult Health Examination & Medicare Annual Wellness Visit
6.1 ACIP Adult Respiratory Vaccines: Influenza, COVID-19, RSV & Pneumococcal
Key Takeaways Explain This Topic AI
Adults aged 65 and older should preferentially receive one of three enhanced influenza vaccines: Quadrivalent High-Dose inactivated vaccine (Fluzone High-Dose), Adjuvanted inactivated vaccine (Fluad), or Quadrivalent Recombinant vaccine (Flublok); if none is available, standard-dose unadjuvanted vaccine should be given.
The ACIP egg allergy guidance explicitly states that any licensed, age-appropriate influenza vaccine (egg-based or non-egg-based) can be administered to individuals with egg allergy of any severity without special observation periods or allergy consultation.
RSV vaccination is recommended as a single lifetime dose for all adults aged 75 and older, and for adults aged 50-74 with high-risk conditions (chronic heart failure, COPD, asthma, CKD, diabetes mellitus, severe obesity, nursing home residency) using Arexvy, Abrysvo, or mResvia; CDC adopted the 50-74 band in June 2025, replacing the earlier 60-74 band. Maternal RSV (Abrysvo only) is administered at 32-36 weeks gestation.
ACIP lowered the age-based pneumococcal conjugate recommendation from 65 to 50 years on October 23, 2024, so all PCV-naive adults aged 50 and older are due on age alone, plus adults aged 19-49 with chronic medical conditions, asplenia, or immunocompromise; preferred options are single-dose PCV20, single-dose PCV21 (Capvaxive, covering 84% of adult IPD serotypes), or PCV15 followed by PPSV23 at least 1 year later (at least 8 weeks for immunocompromised hosts).
Updated COVID-19 vaccination is recommended annually for all individuals aged 6 months and older; moderately or severely immunocompromised adults qualify for additional doses (e.g., an additional updated dose 2 months after the prior dose) to optimize humoral protection.
Last updated: September 2026
Epidemiology and Burden of Vaccine-Preventable Adult Respiratory Diseases
Acute respiratory infections represent one of the leading causes of preventable adult morbidity, functional decline, hospitalization, and mortality in the United States. Four major respiratory pathogens— Influenza viruses (types A and B) , Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) , Respiratory Syncytial Virus (RSV) , and Streptococcus pneumoniae (pneumococcus) —disproportionately afflict older adults (aged ≥ 65 years) and individuals with underlying chronic cardiopulmonary, renal, hepatic, or metabolic multimorbidity.
In older adults, the physiological process of immunosenescence —characterized by thymic involution, reduced naive T-cell diversity, blunted germinal center responses, and impaired plasma cell antibody affinity maturation—substantially weakens host defense against respiratory pathogens. Consequently, infection frequently triggers catastrophic cascades, including acute exacerbations of heart failure, chronic obstructive pulmonary disease (COPD) decompensation, secondary bacterial superinfections, acute kidney injury, and accelerated functional disability. Maintaining comprehensive, up-to-date knowledge of the Advisory Committee on Immunization Practices (ACIP) adult immunization schedule is therefore essential for board certification and ambulatory clinical excellence.
- Annual Influenza Immunization: Formulations, Enhanced Vaccines & Egg Allergy
- Universal Recommendation & Seasonality
The ACIP recommends universal annual influenza vaccination for all individuals aged 6 months and older who do not have specific contraindications. Because influenza viruses undergo continuous antigenic variation through point mutations in surface glycoproteins ( antigenic drift ), annual reformulation of vaccines is required.
Vaccination Timing : Vaccination should ideally be offered during September and October . Vaccination in July and August should generally be avoided for non-pregnant adults because antibody titers wane over the course of the 6- to 8-month season, potentially leaving patients vulnerable during late-winter peaks (February–March). Exceptions to avoid delayed administration include pregnant individuals in their third trimester (to protect the infant) and children requiring a 2-dose series.
Unvaccinated Encounters : Vaccination should continue to be offered throughout the entire influenza season (even into February, March, or later) as long as influenza viruses are circulating.
Enhanced Formulations for Adults Aged ≥ 65 Years
Standard-dose unadjuvanted inactivated influenza vaccines elicit lower seroconversion rates and faster antibody waning in older adults. To overcome immunosenescence, ACIP preferentially recommends that adults aged 65 and older receive one of three enhanced influenza vaccines :
Quadrivalent High-Dose Inactivated Influenza Vaccine (HD-IIV4, Fluzone High-Dose Quadrivalent) :
Antigen Content : Contains 60 μg of hemagglutinin (HA) per vaccine strain (total of 240 μg across 4 strains)—precisely 4 times the antigen content of standard-dose vaccines (15 μg HA per strain).
Clinical Evidence : Randomized double-blind trials demonstrate a 24% relative efficacy improvement in preventing laboratory-confirmed influenza compared to standard-dose vaccine, with substantial reductions in pneumonia hospitalizations and all-cause mortality.
Adjuvanted Inactivated Influenza Vaccine (aIIV4, Fluad Quadrivalent) :
Mechanism : Contains standard-dose HA (15 μg per strain) formulated with MF59 , an oil-in-water emulsion of squalene.
Immunologic Effect : MF59 recruits antigen-presenting cells (monocytes, macrophages, dendritic cells) to the local injection site, enhances antigen uptake, and stimulates broader, cross-reactive antibody responses against drifted viral strains.
Quadrivalent Recombinant Influenza Vaccine (RIV4, Flublok Quadrivalent) :
Production Technology : Produced via recombinant DNA technology using a baculovirus expression vector system in a continuous insect cell line ( Spodoptera frugiperda ), completely free of chicken eggs, antibiotics, and live influenza virus.
Antigen Content : Contains 45 μg of hemagglutinin per strain ( 3 times the standard dose ).
Clinical Evidence : Demonstrates superior relative efficacy compared to standard-dose inactivated vaccines in adults aged 50 and older.
Important
Clinical Rule on Vaccine Availability : If none of the three preferentially recommended enhanced influenza vaccines (HD-IIV4, aIIV4, RIV4) is available at the clinical encounter, the patient should NOT be turned away or have vaccination delayed. An age-appropriate standard-dose unadjuvanted quadrivalent inactivated influenza vaccine should be administered immediately.
ACIP Guidance on Egg Allergy: The Complete Paradigm Shift
Historically, influenza vaccine guidance involved complex screening questionnaires dividing egg-allergic patients into those experiencing mild hives versus angioedema, respiratory distress, or anaphylaxis. Patients were subjected to 30-minute waiting periods, skin testing, or restricted exclusively to egg-free formulations (Flublok or Flucelvax).
The Current ACIP Guideline is Universal and Unconditional :
Any licensed, recommended, age-appropriate influenza vaccine (egg-based or non-egg-based) may be administered to any person with an egg allergy of any severity.
Egg allergy of any degree—including severe life-threatening anaphylaxis requiring epinephrine, emergency room resuscitation, or ICU admission—is no longer an ACIP contraindication or precaution to any influenza vaccine.
No special post-vaccination observation periods (beyond the standard 15 minutes recommended for all vaccines to prevent syncope-related injury) or allergy subspecialty consultations are required.
The only absolute contraindication is a documented history of severe allergic reaction (anaphylaxis) to a prior dose of influenza vaccine or a known severe allergy to a non-egg component of the vaccine.
Live Attenuated Influenza Vaccine (LAIV4, FluMist)
Format & Target Population : Intranasal spray approved exclusively for healthy, non-pregnant individuals aged 2 through 49 years .
Absolute Contraindications : Pregnancy, immunocompromising conditions (HIV with low CD4, chemotherapy, immunosuppressants), anatomical or functional asplenia, cerebrospinal fluid (CSF) leaks, cochlear implants, close contacts or caregivers of severely immunocompromised persons requiring protective isolation, and concurrent use of aspirin-containing therapy in children/adolescents.
Antiviral Interaction : Antiviral medications (oseltamivir, zanamivir within 48 hours; peramivir within 5 days; baloxavir within 17 days) inhibit replication of the live attenuated vaccine virus, blunting efficacy. If taken, LAIV must be delayed or revaccination scheduled.
- COVID-19 Immunization: Formulations, Schedules & Immunocompromise
- Vaccine Platforms and Formulations
COVID-19 vaccination continues to provide essential protection against hospitalization, intensive care admission, and post-acute sequelae of COVID-19 (PASC / Long COVID). Formulations are updated annually to target predominant circulating SARS-CoV-2 spike protein lineages (e.g., JN.1 and KP lineages):
mRNA Vaccines :
BNT162b2 (Pfizer-BioNTech / Comirnaty) : Formulated in lipid nanoparticles encoding full-length prefusion-stabilized spike glycoprotein.
mRNA-1273 (Moderna / Spikevax) : Lipid nanoparticle mRNA formulation.
Protein Subunit Vaccine :
NVX-CoV2373 (Novavax) : Recombinant SARS-CoV-2 spike protein nanoparticles formulated with Matrix-M adjuvant (saponin-based). Useful alternative for patients with mRNA vaccine hesitancy or confirmed polyethylene glycol (PEG) allergy.
ACIP Routine Schedule for Immunocompetent Adults
All adults aged 19 and older should receive 1 dose of the updated annual seasonal COVID-19 vaccine , regardless of their prior vaccination history, provided at least 8 weeks have elapsed since their most recent prior COVID-19 vaccine dose.
Regimen for Moderately or Severely Immunocompromised Adults
Eligible Cohort : Solid organ transplant recipients, hematologic malignancy patients on active chemotherapy, CAR-T cell or hematopoietic stem cell transplant (HSCT) recipients within 2 years, advanced or untreated HIV (CD4 < 200 cells/μL), patients taking high-dose corticosteroids (≥ 20 mg prednisone equivalent daily for ≥ 14 days), and patients receiving B-cell depleting biologics (rituximab) or TNF inhibitors.
Regimen : Recommended to receive an initial 3-dose series of updated mRNA vaccine, with the option to receive 1 or more additional updated doses at least 2 months following the last updated dose , guided by clinical judgment and shared decision-making to optimize circulating neutralizing antibody titers.
Rare Adverse Events: Myocarditis and Pericarditis
Epidemiology : Rare cases of myocarditis and pericarditis have been observed following mRNA vaccination, predominantly in adolescent and young adult males (ages 12–29 years), typically within 7 days of the second dose .
Clinical Course : The clinical presentation is overwhelmingly mild, with rapid resolution following short courses of nonsteroidal anti-inflammatory drugs (NSAIDs) and rest.
Risk-Benefit Calculus : The risk of severe myocardial injury, arrhythmias, multisystem inflammatory syndrome (MIS), and death from wild-type SARS-CoV-2 infection vastly exceeds the risk of post-vaccination myocarditis across all age demographics.
- Respiratory Syncytial Virus (RSV) Immunization in Older Adults & Pregnancy
- Disease Burden and Pathophysiology
Respiratory syncytial virus is an enveloped, negative-sense single-stranded RNA pneumovirus that causes severe lower respiratory tract disease (LRTD) in older adults. In the United States, RSV is responsible for an estimated 60,000–160,000 hospitalizations and 6,000–10,000 deaths annually among adults aged 65 and older. The primary antigenic target for protective neutralizing antibodies is the RSV Fusion (F) glycoprotein , specifically stabilized in its prefusion conformation (preF) .
Approved Adult Formulations
Arexvy (GSK) : Recombinant RSV glycoprotein F stabilized in prefusion conformation (RSVPreF3, 120 μg) formulated with the AS01E adjuvant system (containing QS-21 saponin and monophosphoryl lipid A). FDA-approved for adults aged ≥ 60 years and, since June 2024, for adults aged 50–59 years at increased risk of RSV lower respiratory tract disease (LRTD).
Abrysvo (Pfizer) : Bivalent recombinant RSV prefusion F protein containing 60 μg of subgroup A and 60 μg of subgroup B prefusion F antigens ( unadjuvanted ). FDA-approved for adults aged ≥ 60 years, for adults aged 18–59 years at increased risk of LRTD, AND for pregnant individuals at 32–36 weeks gestation.
mResvia (Moderna) : mRNA vaccine (mRNA-1345) encoding the stabilized prefusion F glycoprotein encapsulated in lipid nanoparticles. FDA-approved for adults aged ≥ 60 years and for adults aged 18–59 years at increased risk of LRTD.
Note
Licensure is broader than the recommendation. Abrysvo and mResvia are licensed down to age 18 for at-risk adults, but as of the current schedule ACIP judged the evidence insufficient to recommend routine RSV vaccination in adults aged 18–49. Answer recommendation questions from the ACIP band (≥ 75 universal; 50–74 risk-based), not from the package insert.
ACIP Recommendations for Older Adults
Adults Aged ≥ 75 Years : Universal recommendation for a single lifetime dose of any approved RSV vaccine (Arexvy, Abrysvo, or mResvia).
Adults Aged 50–74 Years : Risk-stratified recommendation for a single lifetime dose if they have one or more high-risk conditions for severe RSV disease. ACIP voted in April 2025 to extend this band down from 60 to 50 years , and CDC adopted it in June 2025 ; the current CDC adult schedule reads "50 through 74 years." High-risk conditions include:
- Chronic cardiovascular disease : Heart failure, coronary artery disease, cardiomyopathies
- Chronic pulmonary disease : COPD, asthma, interstitial lung disease, cystic fibrosis
- Chronic renal disease : End-stage renal disease (ESRD), hemodialysis, stage 4–5 CKD
- Chronic liver disease : Cirrhosis, hepatic failure
- Diabetes mellitus : Especially with end-organ damage or requiring pharmacotherapy
- Severe obesity : Body mass index (BMI) ≥ 40 kg/m²
- Immune compromise : Moderate or severe immunocompromising conditions
- Congregate living : Residence in a nursing home or long-term care facility
Dosing Frequency : RSV vaccination is currently administered as a single lifetime dose . It is not an annual seasonal booster. It may be coadministered with influenza and COVID-19 vaccines during the same encounter at distinct anatomical sites.
Safety Profile : Post-licensure safety surveillance identified a rare association with Guillain-Barré syndrome (GBS) , estimated at approximately 1 to 2 cases per 100,000 doses administered.
Maternal RSV Immunization (Protecting the Infant)
Sole Approved Formulation : Abrysvo ONLY . (Arexvy is NOT approved in pregnancy due to a non-statistically significant imbalance in preterm births observed in clinical development).
Gestational Window : Administered strictly between 32 0/7 and 36 6/7 weeks of gestation .
Seasonality : Administered seasonally from September through January in most of the continental United States (timed to protect infants born during peak winter RSV transmission).
Infant Protection Strategy : Maternal vaccination stimulates high titers of maternal neutralizing anti-F IgG, which actively cross the placenta via Fc receptors, conferring >80% protection against severe infant RSV lower respiratory tract disease during the first 6 months of life. If the mother receives Abrysvo at least 14 days prior to delivery, the infant does not need the long-acting monoclonal antibody nirsevimab (Beyfortus) , unless born <34 weeks gestation or undergoing cardiopulmonary bypass.
- Streptococcus pneumoniae Immunization: The Modern Conjugate Era
- Pathophysiology & Polysaccharide vs Conjugate Immunobiology
Streptococcus pneumoniae is an encapsulated gram-positive diplococcus with more than 100 known capsular serotypes. The polysaccharide capsule protects the bacterium from phagocytosis, facilitating colonization, mucosal invasion (otitis media, sinusitis, non-bacteremic community-acquired pneumonia), and Invasive Pneumococcal Disease (IPD) —defined as isolation of pneumococcus from normally sterile body sites (bacteremic pneumonia, meningitis, and septic shock), which carries a 10–20% mortality in older adults.
Immunological Feature Pneumococcal Polysaccharide Vaccine (PPSV23) Pneumococcal Conjugate Vaccines (PCV15, PCV20, PCV21)
Mechanism of Activation T-cell-independent B-cell receptor cross-linking T-cell-dependent antigen presentation via MHC Class II
Carrier Protein None (pure capsular polysaccharide antigens) Covalently conjugated to non-toxic diphtheria protein CRM₁₉₇
Immunologic Memory Does NOT induce memory B cells; transient antibody surge Induces robust, durable memory B cells and plasma cells
Mucosal Immunity Minimal mucosal IgA; no reduction in mucosal carriage Stimulates mucosal IgA; eradicates nasopharyngeal carriage (herd immunity)
Repeat Dosing Effect Risk of immune hyporesponsiveness (blunted antibody responses) Priming effect; durable, boosterable memory responses
Efficacy in Young/Old Poorly immunogenic in infants <2 years and frail older adults Highly immunogenic across all age groups including infants and immunocompromised
ACIP Pneumococcal Recommendations for Vaccine-Naive Adults
Important
The age-based threshold moved from 65 to 50. On October 23, 2024 ACIP voted to recommend a single dose of PCV for all PCV-naive adults aged ≥ 50 years , down from the previous age ≥ 65 trigger (published as MMWR Morb Mortal Wkly Rep 2025;74:1–8). Questions written to the pre-2024 rule are now wrong; "defer the conjugate until age 65" is a classic stale distractor.
Adults eligible for pneumococcal immunization include:
All adults aged ≥ 50 years who have not previously received a pneumococcal conjugate vaccine (age-based recommendation, no risk condition required).
Adults aged 19–49 years with underlying medical conditions or risk factors:
Chronic medical conditions : Alcoholism, chronic heart disease (CHF, cardiomyopathies; excluding isolated hypertension), chronic liver disease (cirrhosis), chronic lung disease (COPD, asthma), cigarette smoking, diabetes mellitus.
High-risk conditions (immunocompromise, asplenia, leaks) : Functional or anatomical asplenia (sickle cell disease, splenectomy), CSF leak, cochlear implant, chronic renal failure, nephrotic syndrome, congenital or acquired immunodeficiency, generalized malignancy, HIV infection, Hodgkin disease, immunosuppressive therapy (chemotherapy, systemic corticosteroids), solid organ transplant, multiple myeloma.
The Three Conjugate Options for Vaccine-Naive Adults
Option 1: Single-Dose PCV20 (Prevnar 20) alone.
Administer 1 dose of PCV20. The pneumococcal series is complete . No subsequent PPSV23 is needed.
Option 2: Single-Dose PCV21 (Capvaxive) alone (2024 ACIP Addition):
Contains capsular polysaccharides from 21 serotypes, 8 of which are unique to PCV21 (15A, 16F, 23A, 23B, 24F, 31, 35B, 39) and absent from PCV20 and PPSV23.
Specifically engineered to cover 84% of adult invasive pneumococcal disease serotypes (compared to ~52% covered by PCV20).
Administer 1 dose of PCV21. The series is complete . No subsequent PPSV23 is needed.
Option 3: PCV15 (Vaxneuvance) Followed by PPSV23 (Pneumovax 23) :
Administer 1 dose of PCV15, followed by a dose of PPSV23.
Standard Interval : Administer PPSV23 ≥ 1 year later for immunocompetent adults without high-risk conditions.
Shortened Interval : Administer PPSV23 ≥ 8 weeks later for adults with immunocompromising conditions, functional or anatomical asplenia, CSF leak, or cochlear implants.
Catch-Up Protocols for Adults Previously Vaccinated
Previously Received PPSV23 Alone : Administer 1 dose of PCV20 or PCV21 at least 1 year after the last PPSV23 dose. The series is complete.
Previously Received PCV13 Alone : Administer 1 dose of PCV20 or PCV21 at least 1 year after PCV13; OR complete the previously recommended series by administering PPSV23 (at least 1 year after PCV13 for immunocompetent, or at least 8 weeks for immunocompromised).
Previously Received Both PCV13 and PPSV23 : If all recommended prior doses were received, the patient is considered protected. However, clinicians may administer 1 dose of PCV20 or PCV21 at least 5 years after the last pneumococcal dose based on shared clinical decision-making, particularly in adults with high-risk conditions.
Adult Respiratory Vaccine Master Summary Table
Vaccine Target Population Regimen & Interval High-Yield Board Exam Pearls
Influenza Universal ≥ 6 months Annual single dose (September–October) Prefer HD-IIV4, aIIV4, or RIV4 for age ≥ 65. Universal egg allergy guidance: any licensed vaccine may be given regardless of allergy severity.
COVID-19 Universal ≥ 6 months Annual updated dose (≥ 8 weeks post-prior dose) Moderately/severely immunocompromised may receive additional updated doses ≥ 2 months apart. mRNA vs protein subunit (Novavax).
RSV (Adults) Age ≥ 75 universal; age 50–74 with chronic conditions Single lifetime dose (Arexvy, Abrysvo, or mResvia) Single dose; not annual. Rare Guillain-Barré syndrome risk (~1–2/100,000). May coadminister with influenza/COVID-19.
RSV (Maternal) Pregnant females at 32 0/7–36 6/7 weeks gestation Single dose (Abrysvo ONLY) administered Sept–Jan Arexvy contraindicated in pregnancy. Protects infant for first 6 months. Replaces nirsevimab if given ≥ 14 days before birth.
Pneumococcal (Naive) All adults ≥ 50 (ACIP, October 23, 2024); adults 19–49 with chronic/high-risk conditions PCV20 alone; OR PCV21 alone; OR PCV15 followed by PPSV23 PCV21 covers 84% of adult IPD serotypes (8 unique serotypes). Interval between PCV15 and PPSV23 is ≥ 1 year (≥ 8 weeks if immunocompromised).