USPSTF Grade A/B Screening Guidelines, Pediatric/Adult Immunization Schedules, Travel Prophylaxis & Geriatric Prevention

Memorize the four core USPSTF Grade A/B cancer screening pillars: (1) Lung Cancer Screening (Grade B): Order an annual low-dose computed tomography (LDCT) of the chest in asymptomatic adults aged 50 to 80 years who have at least a 20 pack-year smoking history AND either currently smoke or have quit within the past 15 years. Stop annual LDCT once the patient turns 81, has been smoke-free for more than 15 years, or develops a severe comorbidity that precludes curative lung surgery. (Never order chest X-rays or sputum cytology for lung cancer screening!) (2) Colorectal Cancer Screening (Grade B for ages 45–49; Grade A for ages 50–75): Screen all average-risk adults aged 45 to 75 years using Gold-Standard colonoscopy every 10 years, annual high-sensitivity Fecal Immunochemical Testing (FIT) every 1 year, multitarget stool DNA-FIT (Cologuard) every 1 to 3 years, CT colonography every 5 years, or flexible sigmoidoscopy every 5 years (or every 10 years with annual FIT). For ages 76 to 85, screening is individualized (Grade C), and after age 85 screening is discontinued. If a patient has a first-degree relative diagnosed with colorectal cancer before age 60, start colonoscopy at age 40 OR 10 years younger than the relative's diagnosis (whichever comes first) and repeat every 5 years. (3) Breast Cancer Screening (Grade B): Perform biennial (every 2 years) screening mammography in average-risk women aged 40 to 74 years. (4) Cervical Cancer Screening (Grade A): Begin at age 21 (never screen immunocompetent women under age 21 regardless of sexual debut age!); for ages 21 to 29, perform cervical cytology (Pap smear) alone every 3 years (do NOT perform routine primary HPV testing under age 30 due to high transient HPV clearance); for ages 30 to 65, perform primary high-risk HPV testing every 5 years, Pap + hrHPV co-testing every 5 years, or Pap smear alone every 3 years. Discontinue cervical screening after age 65 if the patient has had adequate negative prior screening (3 consecutive negative Pap smears or 2 consecutive negative HPV/co-tests within the past 10 years, with the most recent within 5 years) and no history of CIN 2/3, OR after a total hysterectomy (with removal of the cervix) performed for benign disease (e.g., uterine fibroids).

Board exams routinely present an anxious, asymptomatic average-risk patient requesting a 'full-body cancer screen' or tumor marker panel. For Prostate Cancer Screening (PSA), the USPSTF assigns Grade C for men aged 55 to 69 years—meaning clinicians should engage in individualized shared decision-making weighing the small reduction in metastatic prostate cancer against the substantial harms of false-positive biopsies, overdiagnosis of indolent tumors, erectile dysfunction, and urinary incontinence—and assigns Grade D (do NOT screen) for men aged 70 years and older. Furthermore, the USPSTF assigns Grade D (recommend AGAINST screening in asymptomatic average-risk adults) for: Ovarian cancer (transvaginal ultrasound and CA-125 in average-risk women lead to unnecessary oophorectomies without reducing mortality), Pancreatic cancer, Testicular cancer, Bladder cancer, and Thyroid cancer (neck palpation or ultrasound).

Master the exact demographic rules for vascular, bone, and cardiometabolic prevention: (1) Abdominal Aortic Aneurysm (AAA) Screening (Grade B): Perform a one-time abdominal duplex ultrasonography in men aged 65 to 75 years who have EVER smoked (defined as 100 or more lifetime cigarettes, even if they quit 40 years ago!). In men aged 65 to 75 who have never smoked, offer selective screening (Grade C) only if there is a first-degree family history of AAA; in women who have never smoked and have no family history, routine AAA screening is Grade D. Recall the AAA surveillance and surgical repair thresholds once detected: AAA 3.0 to 3.9 cm = ultrasound every 3 years; AAA 4.0 to 4.9 cm = ultrasound every 12 months; AAA 5.0 to 5.4 cm = ultrasound every 6 months; AAA ≥5.5 cm in men (≥5.0 cm in women), rapid expansion >0.5 cm in 6 months (>1.0 cm/year), or any symptomatic AAA (abdominal/back pain, tenderness) = elective/emergent endovascular (EVAR) or open surgical repair! (2) Osteoporosis Screening (Grade B): Order a central hip and lumbar spine DEXA scan in all women aged 65 years and older, and in postmenopausal women younger than 65 whose 10-year FRAX fracture risk equals or exceeds that of a 65-year-old white woman without risk factors (or patients on chronic systemic glucocorticoids ≥3 months). A T-score of -1.0 or higher is normal; -1.0 to -2.4 is osteopenia; and -2.5 or lower (or a fragility hip/vertebral fracture) defines osteoporosis (treated first-line with oral bisphosphonates like alendronate plus calcium and vitamin D). (3) Hypertension, Diabetes & Statins: Screen blood pressure annually in adults ≥40 (or high risk; confirm out-of-office with ambulatory or home BP monitoring before starting therapy!); screen for prediabetes/type 2 diabetes (HbA1c or fasting glucose) in overweight or obese adults (BMI ≥25) aged 35 to 70 years; and initiate a moderate-intensity statin for primary CVD prevention in adults aged 40 to 75 with ≥1 CVD risk factor (dyslipidemia, diabetes, HTN, smoking) and a 10-year ASCVD risk ≥10% (note: low-dose aspirin initiation for primary CVD prevention in adults ≥60 years is Grade D due to bleeding risk!).

In infectious and maternal-child prevention: (1) Hepatitis C Virus (HCV) (Grade B): Screen all adults aged 18 to 79 years at least once with anti-HCV antibody followed by reflex HCV RNA PCR. (2) HIV Screening (Grade A): Screen all adolescents and adults aged 15 to 65 years and all pregnant women using a 4th-generation HIV-1/2 antigen/antibody combination immunoassay, and prescribe HIV Pre-Exposure Prophylaxis (PrEP) (oral tenofovir-emtricitabine or injectable cabotegravir) to high-risk HIV-negative individuals. (3) Chlamydia and Gonorrhea (Grade B): Screen all sexually active women aged 24 years and younger (and women ≥25 with new/multiple partners) annually via nucleic acid amplification testing (NAAT). (4) Obstetric & Neonatal Prophylaxis: Prescribe daily folic acid (400 to 800 mcg/day; 4,000 mcg = 4 mg/day if prior child had a neural tube defect or mother takes valproate/carbamazepine) starting at least 1 month before conception; initiate low-dose aspirin (81 mg/day) starting at 12 weeks gestation in pregnant women at high risk for preeclampsia (prior preeclampsia, multifetal gestation, chronic HTN, T1DM/T2DM, renal disease, or autoimmune SLE/APS); screen for gestational diabetes at 24 to 28 weeks and Group B Streptococcus (GBS) rectovaginal culture at 36 to 37 weeks; and administer universal erythromycin ophthalmic ointment (prevents gonococcal ophthalmia neonatorum) and intramuscular Vitamin K1 (phytonadione) (prevents vitamin K deficiency bleeding) to all newborns at birth.

Organize the pediatric schedule by milestone visits: (1) At Birth: Administer the first dose of monovalent Hepatitis B vaccine before hospital discharge (if the mother is HBsAg-positive, give HepB vaccine PLUS Hepatitis B Immune Globulin [HBIG] within 12 hours of birth; if birth weight is under 2,000 grams in an HBsAg-negative mother, delay the first HepB dose until 1 month of age or hospital discharge). (2) At 2, 4, and 6 Months ('2-4-6 Core Pentad'): Administer Oral Rotavirus (RV) (2 doses at 2 and 4 months for Rotarix, or 3 doses at 2, 4, and 6 months for RotaTeq—note that the first dose must be given before 15 weeks of age and all doses completed by 8 months of age, and rotavirus is strictly contraindicated if the infant has a history of intussusception or SCID!), DTaP (diphtheria, tetanus, acellular pertussis at 2, 4, 6, 15–18 months, and 4–6 years), Haemophilus influenzae type b (Hib) conjugate vaccine, Pneumococcal conjugate vaccine (PCV15/PCV20), and Inactivated Poliovirus (IPV) (plus HepB #2 at 1–2 months and #3 at 6–18 months, and annual inactivated influenza starting at 6 months of age). (3) At 12 to 15 Months ('1-Year Live Viral & Hepatitis A Milestone'): Administer the first dose of MMR (measles, mumps, rubella) and Varicella (never given routinely before 12 months because persistent maternal transplacental IgG antibodies neutralize the live-attenuated virus—except between 6 and 11 months prior to international travel, which still requires 2 full doses after age 12 months!), plus the 2-dose Hepatitis A series (12–23 months, 6 months apart) and booster doses of Hib, PCV, and DTaP. (4) At 4 to 6 Years ('Kindergarten Entry Boosters'): Administer second doses of MMR #2 and Varicella #2 alongside DTaP #5 and IPV #4. (5) At 11 to 12 Years ('Adolescent Platform'): Administer a single booster of Tdap (note lower diphtheria/pertussis antigen dose 'd/ap' for ages ≥7 years), the Quadrivalent Meningococcal Conjugate vaccine (MenACWY) (with a mandatory booster at age 16; plus shared decision-making for Serogroup B Meningococcal [MenB] at ages 16 to 23), and the 9-valent Human Papillomavirus (HPV) vaccine (routinely initiated at age 11–12, can start at age 9: requires only 2 doses spaced 6–12 months apart if started before age 15, but requires 3 doses [0, 1–2, 6 months] if started at age 15 or older or in immunocompromised patients!).

Board questions frequently try to trick examinees into delaying vaccinations for benign reasons. NEVER delay routine childhood vaccinations for: (1) mild acute illness (low-grade fever, viral upper respiratory infection, otitis media, or mild diarrhea), (2) current antimicrobial therapy, (3) household contact with a pregnant woman or immunosuppressed family member (with the sole exception of avoiding oral poliovirus, smallpox, and recommending that severely immunocompromised bone-marrow transplant recipients avoid changing the diapers of an infant for 4 weeks after oral rotavirus vaccination; MMR and Varicella do NOT shed dangerously to pregnant household contacts!), (4) breastfeeding, or (5) prematurity (preterm infants must be vaccinated according to their chronological age from birth, NOT gestational-corrected age!). Furthermore, egg allergy (even anaphylaxis to egg!) is NO LONGER a contraindication to MMR or Influenza vaccines (only Yellow Fever vaccine requires specialist desensitization in severe egg anaphylaxis). Conversely, TRUE absolute contraindications include: (1) anaphylaxis to a prior dose or vaccine component (such as neomycin or gelatin in MMR/Varicella, or baker's yeast in Hepatitis B), (2) encephalopathy within 7 days of a prior DTaP/Tdap dose (switch to Td without pertussis; note that a simple febrile seizure or fever is NOT a contraindication to future DTaP!), (3) history of intussusception or SCID for Rotavirus, and (4) pregnancy or severe T-cell immunodeficiency (CD4 <200) for all live-attenuated vaccines.

Master the four high-yield adult immunization protocols: (1) Pneumococcal Vaccination: Indicated universally in all adults aged 65 years and older, AND in adults aged 19 to 64 years with chronic medical or immunocompromising conditions (chronic heart, lung [COPD/asthma], liver, or kidney disease, diabetes mellitus, cigarette smoking, alcoholism, cochlear implants, CSF leaks, functional/anatomic asplenia [sickle cell/splenectomy], HIV, malignancy, or immunosuppressive therapy). Under current ACIP guidelines, administer either a single dose of PCV20 (or PCV21) alone (which completes the series!) OR 1 dose of PCV15 followed by 1 dose of PPSV23 at least 1 year later (or at least 8 weeks later in immunocompromised patients, asplenia, CSF leak, or cochlear implant!). (2) Herpes Zoster (Shingles) Vaccination: Administer 2 doses (2 to 6 months apart) of the recombinant adjuvanted zoster vaccine (RZV / Shingrix) to all immunocompetent adults aged 50 years and older AND immunocompromised adults aged 19 years and older—regardless of whether they recall having chickenpox, have already had an episode of shingles, or previously received the older live Zostavax vaccine! Because Shingrix is a recombinant subunit vaccine (NOT live), it is safe in HIV and immunosuppressed patients. (3) Pregnancy Immunization Mandate: Every pregnant woman must receive Tdap between 27 and 36 weeks gestation during EVERY pregnancy (even if she received Tdap 10 months ago in a prior pregnancy!) to maximize transplacental maternal anti-pertussis IgG transfer to the newborn, plus inactivated influenza vaccine (any trimester) and seasonal maternal RSV bivalent prefusion F vaccine (Abrysvo) at 32 to 36 weeks gestation (or administer the long-acting monoclonal antibody nirsevimab directly to the infant aged <8 months entering their first RSV season). (4) Adult RSV Vaccination: Recommended for all adults aged 75 years and older and adults aged 60 to 74 years with chronic cardiopulmonary or metabolic comorbidities.

When an unvaccinated or susceptible patient is exposed to a contagious pathogen, rapid post-exposure prophylaxis prevents clinical disease: (1) Varicella Exposure: In a susceptible, immunocompetent, non-pregnant child or adult exposed to chickenpox, administer the live Varicella vaccine within 3 to 5 days of exposure; in a susceptible pregnant woman, immunocompromised patient, or premature neonate (where live vaccine is contraindicated!), administer passive Varicella-Zoster Immune Globulin (VariZIG) within 10 days (or oral acyclovir/valacyclovir if VariZIG is unavailable). (2) Measles Exposure: In susceptible immunocompetent contacts (≥6 months old), give the MMR vaccine within 72 hours of exposure; in pregnant women, infants <6 months, and severely immunocompromised contacts, give Intravenous/Intramuscular Immune Globulin (IG) within 6 days. (3) Hepatitis A Exposure: Give single-antigen Hepatitis A vaccine within 2 weeks of exposure for healthy individuals aged 1 to 40 years (add passive Immune Globulin for adults >40, immunocompromised, or chronic liver disease patients). (4) Neisseria meningitidis Exposure: All close household, childcare, or direct respiratory droplet contacts must receive immediate antibiotic chemoprophylaxis with rifampin (2 days, turns body fluids orange and induces CYP450), single-dose oral ciprofloxacin (avoid in pregnancy), or single-dose IM ceftriaxone (drug of choice in pregnancy!). (5) Bordetella pertussis Exposure: Administer post-exposure macrolide prophylaxis (azithromycin) to ALL household contacts regardless of vaccination status!

Most malaria-endemic regions (Sub-Saharan Africa, South/Southeast Asia, Amazon basin) harbor chloroquine-resistant Plasmodium falciparum, requiring one of three first-line prophylactic agents: (1) Atovaquone-Proguanil (Malarone): Taken daily starting only 1 to 2 days before travel and continued for only 7 days after leaving the endemic zone (because it has causal prophylactic activity against hepatic schizonts!). It is the ideal choice for last-minute travelers and short trips, is very well tolerated, and is contraindicated in severe renal impairment (CrCl <30 mL/min) and pregnancy. (2) Doxycycline: Taken daily starting 1 to 2 days before travel and continued for 4 weeks after leaving; inexpensive and additionally prevents leptospirosis and rickettsial infections, but causes phototoxicity (sunburn rash), pill esophagitis, and is strictly contraindicated in pregnancy and children under age 8 (tooth enamel discoloration/bone suppression). (3) Mefloquine: Taken once weekly starting 2 weeks before travel and continued for 4 weeks after leaving; it is the drug of choice for pregnant women traveling to chloroquine-resistant zones, but is strictly contraindicated in patients with a history of depression, anxiety, psychosis, seizures/epilepsy, or cardiac conduction abnormalities (QT prolongation) due to vivid nightmares and neuropsychiatric toxicity! For the few regions with chloroquine-sensitive malaria (Central America west of the Panama Canal, Haiti, Dominican Republic, and parts of the Middle East), weekly chloroquine (or hydroxychloroquine) is safe in all trimesters of pregnancy. For regions heavy in Plasmodium vivax or Plasmodium ovale, primaquine or tafenoquine eradicates dormant hepatic hypnozoites, but requires mandatory quantitative G6PD deficiency testing prior to administration to prevent life-threatening hemolysis.

Traveler's diarrhea is most commonly caused by enterotoxigenic Escherichia coli (ETEC) (watery diarrhea via heat-labile [LT, increases cAMP] and heat-stable [ST, increases cGMP] enterotoxins), followed by Campylobacter jejuni (especially in Southeast Asia), Shigella, Salmonella, and norovirus/Giardia. Prevention centers on strict food and water hygiene ("boil it, cook it, peel it, or forget it"—drink only sealed bottled or boiled water, avoid ice cubes, raw salads, and unpasteurized dairy); routine antibiotic prophylaxis is not recommended for healthy travelers (bismuth subsalicylate can be used for prophylaxis, and azithromycin is the first-line self-treatment for moderate-to-severe or dysenteric traveler's diarrhea). Before travel to developing regions, administer Hepatitis A vaccine and Typhoid vaccination—choosing between the intramuscular Vi capsular polysaccharide vaccine (single dose ≥2 weeks pre-travel; safe in immunocompromised patients and children ≥2 years) and the oral live-attenuated Ty21a vaccine (4 capsules taken every other day for 1 week; contraindicated in pregnancy and immunosuppression). For travel to equatorial Africa or South America, the live-attenuated Yellow Fever vaccine must be administered at least 10 days before arrival for official International Certificate of Vaccination validity (contraindicated in infants <6 months, severe egg allergy, thymus disorders/myasthenia gravis, and severe immunosuppression). For rapid ascents above 2,500 meters, prevent Acute Mountain Sickness (AMS) with gradual ascent and oral acetazolamide (carbonic anhydrase inhibitor that induces a mild proximal renal tubular metabolic acidosis to stimulate central nocturnal hyperventilation).

Every older adult should be screened annually for falls by asking three questions: (1) Have you fallen in the past year? (2) Do you feel unsteady when standing or walking? and (3) Do you worry about falling? Gait and balance are objectively quantified at the bedside using the Timed Up and Go (TUG) test—measuring the time in seconds required for the patient to rise from an armchair, walk 3 meters (10 feet) at a comfortable pace, turn around, walk back, and sit down (a TUG time of 12 seconds or longer indicates high fall risk!). Under USPSTF Grade B guidelines, the single most effective primary care intervention to prevent falls in community-dwelling adults aged ≥65 at increased fall risk is supervised exercise and physical therapy (focusing on balance, gait training, and lower-extremity strength, such as Tai Chi), paired with multifactorial assessment: checking orthostatic vital signs (a drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing), correcting visual acuity (cataract surgery and avoiding multifocal/bifocal lenses while walking on stairs), eliminating home hazards (removing loose throw rugs, adding bathroom grab bars and nightlights), and deprescribing fall-inducing medications (note: routine Vitamin D supplementation in non-deficient community seniors without osteoporosis is NOT recommended by the USPSTF solely for fall prevention).

Polypharmacy (taking ≥5 daily medications) is the most rapidly reversible cause of geriatric delirium, orthostatic syncope, and falls. Under the AGS Beers Criteria, avoid or deprescribe: (1) First-generation antihistamines (diphenhydramine, hydroxyzine, chlorpheniramine), tricyclic antidepressants (amitriptyline), and bladder antimuscarinics (oxybutynin)—potent anticholinergics that cross the blood-brain barrier to precipitate acute delirium, cognitive decline, blurry vision, urinary retention (overflow incontinence in BPH), and constipation; (2) Benzodiazepines (alprazolam, diazepam, lorazepam) and non-benzodiazepine Z-drugs (zolpidem, eszopiclone)—double the risk of nocturnal hip fracture falls and delirium; (3) Peripheral alpha-1 blockers (prazosin, terazosin, doxazosin)—cause severe first-dose orthostatic hypotension and syncope; (4) Long-acting sulfonylureas (glyburide, glimepiride) and sliding-scale insulin—cause severe neuroglycopenic falls; and (5) Chronic NSAIDs—cause peptic ulcer hemorrhage, AKI, and heart failure exacerbation. Additionally, screen for presbycusis (age-related bilateral symmetric high-frequency sensorineural hearing loss caused by cochlear hair cell degeneration), as untreated hearing loss accelerates social isolation and cognitive decline (amplification with hearing aids improves communication and quality of life). Finally, when an older adult with moderate-to-severe Alzheimer dementia (or a patient with uncontrolled epileptic seizures or recurrent syncope) gets lost while driving or has minor fender-benders, counsel the patient and family to cease driving immediately, arrange alternative transportation, and follow state Department of Motor Vehicles (DMV) reporting statutes.