Herpes zoster vaccine. Poorly effective in those who need it most

The results of a clinical trial suggest that zoster vaccination (Zostavax, Sanofi Pasteur MSD) of 1000 healthy persons aged 60 years or over prevents approximately one case of postherpetic neuralgia each year over the next 3 years. Vaccination is less effective in persons over 70 years of age. The results of another clinical trial suggest that vaccination of 1000 healthy persons aged 50 to 59 years prevents about 5 cases of herpes zoster over the following year. The impact on the frequency of postherpetic neuralgia is not known. The vaccine might not be protective in persons who subsequently become immunocompromised. In the trial in persons aged 50 years or older, 50% of vaccinees had mild local adverse effects. It should be noted that the protocol excluded immunocompromised patients, in whom the live vaccine virus could potentially cause clinically significant infection. In one study, the immune response to the vaccine was lower after simultaneous immunisation with a 23-valent pneumococcal polysaccharide vaccine. This live zoster vaccine is contraindicated in immunocompromised individuals, yet they are at highest risk of severe zoster. In practice, zoster vaccination is not sufficiently effective in the elderly to justify its widespread use.