Research has shown that two doses of Shingrix provide strong protection against shingles and postherpetic neuralgia (PHN), the most common complication of shingles, specifically:
• In adults 50 to 69 years old with normal immune systems, Shingrix was about 97% effective in preventing shingles; in adults 70 years and older, Shingrix was 91% effective.
• In adults 50 years and older, Shingrix was 91% effective in preventing PHN; in adults 70 years and older, Shingrix was 89% effective.
• In adults with weakened immune systems, Shingrix was between 68% and 91% effective in preventing shingles, depending on the adult’s underlying immunocompromising condition.
• In people 70 years and older who had normal immune systems, Shingrix immunity remained high even seven years after being vaccinated.
Source: https://www.cdc.gov/vaccines/vpd/shingles/public/shingrix/index.html