Can the shingles vaccine (Shingrix or Zostavax) activate shingles?

Can the Shingles Vaccine Activate Shingles?

No, the shingles vaccine does not activate shingles in immunocompetent individuals, and the recombinant zoster vaccine (Shingrix) cannot cause shingles in any population because it is not a live vaccine. 1

Types of Shingles Vaccines

There are two types of shingles vaccines available:

1. Live Zoster Vaccine (ZVL/Zostavax):

   • Contains live attenuated varicella zoster virus (Oka strain)
   • No longer marketed in the United States but still used in many parts of the world
   • Potency is at least 14 times that of the varicella vaccine 1

2. Recombinant Zoster Vaccine (RZV/Shingrix):

   • Non-live subunit vaccine containing varicella zoster virus glycoprotein E and adjuvant AS01B
   • Currently preferred due to higher efficacy
   • Approved for adults aged ≥50 years 1

Safety Profile Regarding Shingles Activation

For Recombinant Zoster Vaccine (Shingrix):

• Cannot cause shingles as it does not contain live virus, only a protein component of the virus 1
• Safe for use in immunocompromised patients 2
• More reactogenic than placebo, with injection-site reactions, myalgia and fatigue being common but typically mild to moderate and transient 2

For Live Zoster Vaccine (Zostavax):

• Theoretical risk of vaccine-strain viral replication in immunocompromised patients 1
• Despite theoretical concerns, clinical evidence shows it is safer than initially thought:
  • Among 633 Medicare patients inadvertently vaccinated while on biologics, no cases of shingles occurred in the 6 weeks post-vaccination 1
  • In a study of 600 patients on TNF-inhibitors randomized to receive ZVL vs placebo, no cases of varicella infection or zoster were found within the 42-day risk period 1

Special Considerations for Immunocompromised Patients

• For immunocompromised patients:
  • The live vaccine (Zostavax) is generally contraindicated 1
  • One documented case of cutaneous vaccine dissemination occurred in a patient on MTX who started tofacitinib, but this patient lacked primary immunity to varicella and should not have received the live vaccine 1
  • The recombinant vaccine (Shingrix) is preferred and considered safe 2

Efficacy and Recommendations

• Recombinant zoster vaccine (Shingrix):

  • Vaccine efficacy of >90% in clinical trials 3
  • Real-world effectiveness of 70.1% for two doses and 56.9% for one dose 3
  • Effectiveness maintained across age groups, including those >80 years 3
  • Effective even in those with autoimmune or immunosuppressive conditions 3

• Live zoster vaccine (Zostavax):

  • Reduced burden of illness associated with herpes zoster 4
  • Efficacy wanes over time 5

Common Pitfalls and Caveats

1. Timing with other vaccines: If administering two or more live-virus vaccines parenterally, they should be given either simultaneously or separated by at least 28 days to avoid impaired immune response 1

2. Flares in rheumatic disease patients: Some studies have reported disease flares (7-16%) in rheumatic disease patients after receiving the recombinant vaccine, but these were generally mild and self-limiting 1

3. Immunosuppressive therapy considerations:

   • For live vaccines (Zostavax): Should be given at least 4 weeks before starting immunosuppressive therapy or at least 3 months after stopping 1
   • For recombinant vaccine (Shingrix): Can be administered to patients on immunosuppressive therapy 2

In conclusion, while the live zoster vaccine carries a theoretical risk of causing shingles in severely immunocompromised individuals, this is extremely rare in practice. The recombinant zoster vaccine cannot cause shingles under any circumstances as it does not contain live virus. Both vaccines have been shown to be effective in preventing shingles, with the recombinant vaccine demonstrating superior efficacy.