Recently we’ve received many questions about whether to get the shingles (herpes zoster) vaccine. As always, the issue is not as black and white as some would have us believe, so here we discuss what you may not read in the mainstream about the shingles vaccine.
The US Centers for Disease Control and Prevention (CDC) recommends that anyone over the age of 60 receive the shingles vaccine manufactured by vaccine giant Merck. CDC also says that the shingles vaccine is only 51% effective in all those over 60 years of age but this effectiveness, or efficacy, falls to 38% in those over 70.1
So what are the facts around the shingles vaccine?
1) The shingles vaccine is essentially a souped up chicken pox vaccine. The shingles vaccine is made using the same strain of weakened chicken pox used in the pediatric chicken pox vaccine but the shingles vaccine contains at least 14 times as much chicken pox antigen.2
2) Shingles is a live virus vaccine and transmission of shingles from vaccine recipients to susceptible individuals has been documented.3
3) Shingles vaccine contains: aborted fetal tissue, pig gelatin, MSG, bovine calf serum, antibiotics, and more.4
4) Adverse reactions to shingles vaccine include: headache, anaphylaxis, pain in the extremities, pain, erythema (redness of the skin), pruritus (itching), swelling, and chicken pox-like rash at injection site5. In one studied mentioned on the package insert, these reactions were not infrequent with 53.9% of the vaccine group reporting pain, 48.1% reporting erythema, and 40% reporting swelling.6
5) Any immunity induced by the vaccine is not permanent. According to CDC research shows the vaccine lasts 6 years.7
6) Merck and CDC both claim that the vaccine is 51% effective, i.e. that the vaccine reduces an individual’s risk of contracting shingles by 50%. While that 50% reduction sounds impressive, how do they arrive at that figure? The study looked at 19, 254 patients and found that 642 (3.3%)of the placebo or control group developed shingles whereas only 315 (1.6%) of the vaccinated group developed shingles. So while it is true that 1.6% is indeed half or 51% less than 3.3% a more telling way to interpret the numbers would be according to absolute risk. If you aren’t vaccinated for shingles your risk of contracting shingles in the study was 3.3% and the risk of developing shingles in the vaccinated groups was 1.6%. The improvement in risk of developing shingles from being vaccinated is therefore only 1.7% (3.3%-1.6%)!8 Not quite so impressive as the 50% reduction claimed!
7) The biggest concern with shingles is the post-herpetic neuralgia (PHN) or nerve pain that can persist after one has developed shingles. This can be very painful and very debilitating so it is understandable that folks would want to protect against PNH but what do the data say on this front? Merck claims that the vaccine reduces one’s risk of developing PNH by 35%. That said, in the data reported on the package insert, Merck reports that 80 of the control group developed PNH whereas 27 of the vaccinated group developed PNH out of a total of 19,254 patients. So .415% of the control group developed PNH compared to .14% of the vaccinated group and yes .14% is 34% less than .415% but the absolute chances of developing PNH are improved only .275% by being vaccinated. That doesn’t seem very effective to me. Can you imagine being charged for a car repair that only improved your chances of getting back on the road by .275%? I don’t think that car mechanic would be in business for very long!
As always, vaccine choices are personal choices so we aim to provide you with all the information you need to make an informed choice for yourself. You can read more about this and other issues in our Catalogue of Science.