Shingles is a viral disease that manifests itself in painful skin rashes and blisters.
Triggered by the same virus that causes chickenpox, it is expected that one in four people will develop shingles at some point in life, predominantly after the age of 50.
Shingles can be prevented with the use of live-attenuated vaccines, where a weakened form of the virus is introduced into the body. However, their efficacy decreases after the age of 70, and there are certain cases where live-attenuated vaccines are contraindicated, such as in individuals under immunosuppressive therapy.
Recombinant vaccines, on the other hand, use recombinant DNA technology to expose the body to specific viral protein subunits as opposed to the live virus.
These types of vaccines are designed to overcome some of the limitations of live-attenuated vaccines.
Last year, a new recombinant vaccine received regulatory approval and is currently marketed in Canada as Shingrix. Researchers at St. Michael’s Hospital in Toronto recently published a systematic review in the BMJ comparing the live-attenuated shingles vaccine against the recombinant subunit vaccine.
A total of 27 studies representing over 2 million patients above the age of 50 were included in the review.
The recombinant vaccine was found to be 85% more effective in reducing the incidence of shingles but was associated with a 30% greater chance of adverse effects occurring at the site of injection. No significant differences in the rate of severe adverse events were found between vaccines.
The authors suggest that despite its higher risk of side effects, the recombinant subunit vaccine is superior to the live-attenuated vaccine in the prevention of shingles. They recommend future studies to analyze the cost-effectiveness of both treatments, considering that the recombinant vaccine does require two doses compared to only one of the live-attenuated vaccines.
References:
- Tricco AC et al. Efficacy, effectiveness, and safety of herpes zoster vaccines in adults aged 50 and older: systematic review and network meta-analysis. BMJ. 2018 Oct 25;363:k4029. doi: 10.1136/bmj.k4029.
- St. Michael’s Hospital. Systematic review of clinical studies suggests newer shingles vaccine far more effective. https://www.eurekalert.org/pub_releases/2018-10/smh-sro102518.php. Published October 25, 2018
- GSK Canada. SHINGRIX approved in Canada as the first non-live adjuvanted vaccine to help protect against shingles. http://ca.gsk.com/en-ca/media/press-releases/2017/shingrix-approved-in-canada-as-the-first-non-live-adjuvanted-vaccine-to-help-protect-against-shingles/. Published October 13, 2017.
