What are the recommendations for the shingles vaccine in adults aged 50 and older, including those with a history of shingles or weakened immune systems?

Shingles Vaccine Recommendations

All adults aged 50 years and older should receive Shingrix (recombinant zoster vaccine, RZV) as a two-dose series given 2-6 months apart, regardless of prior shingles history, previous Zostavax vaccination, or most immunocompromising conditions. 1, 2

Standard Vaccination Schedule

• Administer Shingrix as two intramuscular doses with the second dose given 2-6 months after the first dose. 1, 2
• The minimum interval between doses is 4 weeks; if given earlier than this, the dose should be repeated. 1
• For immunocompromised adults aged ≥18 years, use a shorter schedule with the second dose given 1-2 months after the first dose. 1, 2

Who Should Receive the Vaccine

Standard Population

• All immunocompetent adults aged ≥50 years should receive Shingrix, with vaccination starting at age 50 (not earlier). 1, 2
• The vaccine demonstrates 97.2% efficacy in preventing herpes zoster in adults aged 50 and older, with protection persisting for at least 8 years with minimal waning (maintaining efficacy above 83.3%). 1

Immunocompromised Adults

• Immunocompromised adults aged ≥18 years should receive Shingrix, including those with:
  • HIV infection 1, 2
  • Hematologic malignancies or solid cancers 1
  • Solid organ or stem cell transplant recipients 1, 2
  • Autoimmune diseases requiring immunosuppressive therapy 1, 2
  • Patients on JAK inhibitors, biologics, or other immunomodulators 1
• Shingrix is the only appropriate vaccine for immunocompromised patients—never use live-attenuated Zostavax in this population. 1, 2

Special Circumstances

Prior Shingles History:

• Vaccinate regardless of prior herpes zoster history, as having had shingles does not provide reliable protection against recurrence (10.3% cumulative recurrence risk at 10 years). 1, 2
• Wait at least 2 months after acute shingles symptoms have resolved before administering the vaccine. 1, 2

Previous Zostavax Vaccination:

• All adults who previously received Zostavax should receive the full 2-dose Shingrix series, as Zostavax efficacy declines to only 14.1% by year 10. 1, 2
• Administer Shingrix at least 2 months after the last Zostavax dose. 1, 2

Patients on Glucocorticoids:

• Shingrix can be safely administered to patients taking low-dose glucocorticoids (prednisone equivalent <10 mg/day) without adversely impacting vaccine response. 1
• Studies show only mild disease flares (4-17%) after vaccination with no serious adverse events. 1

Patients Starting Immunosuppressive Therapy (e.g., Tofacitinib):

• Complete the full 2-dose Shingrix series before starting tofacitinib whenever possible to maximize immune response. 1
• If urgent initiation is required, administer at least the first dose before starting therapy, with the second dose completed 1-2 months later. 1
• Never use live-attenuated Zostavax in patients on or about to start JAK inhibitors. 1

Efficacy Comparison: Shingrix vs. Zostavax

• Shingrix (RZV) demonstrates 92-97.2% effectiveness in preventing herpes zoster at 3.2 years follow-up. 1, 3
• Zostavax (LZV) shows only 51% effectiveness initially, declining to 14.1% by year 10. 1, 3
• Shingrix maintains high efficacy across all age groups, while Zostavax efficacy decreases significantly with age (70% in ages 50-59 vs. 18% in those ≥80 years). 1

Expected Adverse Events

Common Side Effects:

• Injection-site reactions (pain, redness, swelling) occur commonly, with 9.5% experiencing grade 3 injection site reactions compared to 0.4% with placebo. 1
• Systemic symptoms (myalgia, fatigue, headache) were reported in 11.4% of vaccine recipients versus 2.4% in placebo recipients. 1
• Most adverse events are mild to moderate in intensity and resolve within 4 days. 1, 2

Serious Adverse Events:

• No serious safety concerns have been identified in large clinical trials, with similar rates of serious adverse events and deaths between vaccine and placebo groups. 1, 3

Impact on Completion:

• The dropout rate (not returning for the second dose) is higher in the vaccine group than placebo (RR 1.25), with 1% additional risk. 1, 3
• Concerns about tolerability are the leading reason for both non-initiation and non-completion of the vaccine series. 4

Important Clinical Caveats

• No booster doses beyond the initial two-dose series are currently recommended. 1
• If the second dose is administered beyond 6 months, effectiveness is not impaired—do not restart the series. 1
• Shingrix can be administered simultaneously with inactivated influenza vaccines without required waiting periods. 1
• Wait until acute flu symptoms have resolved before vaccinating, but no specific waiting period is required after influenza illness. 1
• Do not delay vaccination to conduct varicella serology in immunocompetent adults aged 50 and older—most adults (88-91%) are VZV-seropositive even without recalled chickenpox history. 5