Zoster vaccine

Zoster vaccination is used to prevent shingles and its complications, including postherpetic neuralgia., which is given as a single shot, Shingrix is given as two identical intramuscular doses, two to six months apart. Shingrix provides high levels of immunity for at least 7 years after vaccination, but it is possible the vaccine may provide protection for much longer. A large randomized clinical trial showed Shingrix reduced the incidence of shingles 96.6% (relative risk reduction, RRR) in the 50–59 age group, and 91.3% (relative risk reduction, RRR) in those over age 70. The absolute decrease in risk (absolute risk reduction, ARR) of herpes zoster following immunization over three and a half years is 3.3% (3.54% down to 0.28%) while the decrease in the risk of postherpetic neuralgia is 0.3% (0.34% down to 0.06%). Zostavax The Zostavax vaccine (both single dose and two-dose regime) is likely effective at protecting people from herpes zoster disease for a duration of up to three years. The degree of longer term protection (beyond 4 years from the initial vaccination) is not clear. The need for re-vaccination after the first full vaccine schedule is complete remains to be confirmed. The FDA originally recommended it for individuals 60 years of age or older who are not severely allergic to any of its components and who meet the following requirements: • do not have a weakened immune system due to HIV/AIDS or another disease or medications (such as steroids, radiation and chemotherapy) that affect the immune system; • do not have a history of cancer affecting the bone marrow or lymphatic system, such as leukemia or lymphoma; and • do not have active, untreated tuberculosis. In 2006, the US Advisory Committee on Immunization Practices (ACIP) recommended that the live vaccine be given to all adults age 60 and over, including those who have had a previous episode of shingles, and those who do not recall having had chickenpox, since more than 99% of Americans ages 40 and older have had chickenpox. ==Side effects==

Shingrix Temporary side effects from the Shingrix shots are likely and can be severe enough in one out of six people to affect normal daily activities for up to three days. Side effects with Shingrix are greater than those with Zostavax and occur more frequently in individuals aged 50 to 69 years compared with those 70 years and older. Zostavax The live vaccine (Zostavax) is very safe; one to a few percent of people develop a mild form of chickenpox, often with about five or six blisters around the injection site, and without fever. The blisters are harmless and temporary. In one study 64% of the Zostavax group and 14% of the controls had some adverse reaction. However, the rates of serious adverse events were comparable between the Zostavax group (0.6%) and those receiving the placebo (0.5%). A study including children with leukaemia found that the risk of getting shingles after vaccination is much lower than the risk of getting shingles for children with natural chicken pox in their history. Data from healthy children and adults point in the same direction. == Composition ==

Shingrix Shingrix is a suspension for intramuscular injection consisting of a lyophilized recombinant varicella zoster virus glycoprotein E antigen that is reconstituted at the time of use with AS01B suspension as an immunological adjuvant. The antigen is a purified truncated form of the glycoprotein, expressed in Chinese hamster ovary cells. The AS01B adjuvant suspension is composed of 3-O-desacyl-4'-monophosphoryl lipid A (MPL) from Salmonella (Minnesota strain) and a saponin molecule (QS-21) purified from Quillaja saponaria (soap bark tree) extract, combined in a liposomal formulation consisting of dioleoyl phosphatidylcholine (DOPC) and cholesterol in phosphate-buffered saline solution. Zostavax Zostavax contains live attenuated varicella-zoster virus. It is injected subcutaneously (under the skin) in the upper arm. The live vaccine is produced using the MRC-5 line of fetal cells. ==Cost effectiveness==

A 2007 study found that the live vaccine is likely to be cost-effective in the US, projecting an annual savings of to million in healthcare costs with cost-effectiveness ratios ranging from to per quality-adjusted life year gained. In 2007, the live vaccine was officially recommended in the US for healthy adults aged 60 and over, but is no longer given out in the United States , given the superiority of Shingrix. In Canada the cost of Shingrix is about for the two doses. ==History==

European Union In 2006, the European Medicines Agency (EMA) issued a marketing authorization for the zoster vaccine to Sanofi Pasteur for routine vaccination in individuals aged 60 and over. Shingrix was approved for medical use in the European Union in March 2018, with an indication for the prevention of herpes zoster (HZ) and post-herpetic neuralgia (PHN) in adults 50 years of age or older. United Kingdom From 2013, the UK National Health Service (NHS) started offering shingles vaccination to elderly people. People aged either 70 or 79 on 1 September 2013, were offered the vaccine. People aged 71 to 78 on that date would only have an opportunity to have the shingles vaccine after reaching the age of 79. The original intention was for people aged between 70 and 79 to be vaccinated, but the NHS later said that the vaccination program was being staggered as it would be impractical to vaccinate everyone in their 70s in a single year. In 2021, vaccination against shingles is available on the NHS to people aged 70 to 79. Since 2023, the shingles vaccines is being offered to healthy people turning 65. United States Zostavax was developed by Merck & Co. and approved and licensed by the US Food and Drug Administration (FDA) in May 2006, Shingrix is a zoster vaccine developed by GlaxoSmithKline that was approved in the United States in October 2017. Shingrix, which provides strong protection against shingles and PHN, was preferred over Zostavax before Zostavax was discontinued. In June 2020, Merck discontinued the sale of Zostavax in the US. Vaccine doses already held by practitioners could still be administered up to the expiration date (none expired later than November 2020). Adults 19 years and older who are immunocompromised because of disease or therapy are also recommended to receive two doses of Shingrix. == Link to lower dementia risk ==

Researchers analyzing the health records of Welsh older adults discovered that those who received Zostavax were 20% less likely to develop dementia over the next seven years than those who did not receive the vaccine. Shingrix appears to have a stronger effect than Zostavax, providing 164 additional days lived without a diagnosis of dementia in those subsequently affected. A June 2025 study suggests that the difference may be attributable to the AS01 adjuvant used in Shingrix as the AS01-containing RSV vaccine (Arexvy) shows a very similar reduction in dementia risks. This hypothesis is corroborated by mouse studies showing a possible anti-dementia effect of AS01. ==References==