INFECTIOUS DISEASE: HERPES ZOSTER
RZV is recommended for the prevention of HZ and related complications for immunocompetent adults previously administered ZVL. in the US in 1995, more than 3.5 million cases of varicella, 9000 hospitalizations, and 100 deaths have been prevented each year by varicella vaccination.1 Children who have been vaccinated against varicella have a lower risk for HZ compared with children who became infected with the varicella virus.1,2 The most common complication of HZ is postherpetic neuralgia (PHN), which occurs in 10% to 18% of those affected. The chronic nerve pain lasts after the blisters have healed.The course of PHN can be severe and life-changing, lasting months to years.3 Early treatment of HZ can reduce the severity and incidence of PHN. Less common but severe complications of HZ include blindness caused by secondary bacterial infection, pneumonia, and hearing problems.1-3 Treatment of Shingles
Treatment of shingles includes antiviral medications, which reduce both the acute pain of herpes zoster and risk for PHN. Antiviral treatment should be started as soon as possible and is most effective when started within 72 hours of rash onset (Table).4
for adults 50 years and older and is preferred over zoster vaccine live (ZVL, Zostavax), which was approved in 2006 and removed from the market in November 2020 because of the superior efficacy of RZV.6,7 RZV is recommended for the prevention of HZ and related complications for immunocompetent adults who previously received ZVL.6 The vaccination consists of 2 doses (0.5 mL each) administered intramuscularly 2 to 6 months apart.6,7 Two doses of RZV are more than 90% effective at preventing HZ and PHN. The vaccine’s effectiveness against HZ remains greater than 85% for at least the first 4 years after vaccination.2 The ACIP also recommended that people with a history of HZ should be vaccinated because HZ can recur. Individuals with a current outbreak of HZ should wait until the acute phase of the disease is over and all lesions have completely healed before getting vaccinated. It is not necessary to screen for a history of varicella before administering the shingles vaccine. However, an individual who presents with negative laboratory evidence of chickenpox probably would not benefit from the vaccine because it does not protect against chickenpox infection.7
Shingles Prevention During COVID-19
According to the Centers for Disease Control and Prevention (CDC), HZ vaccination is an essential preventive care service for older adults that should not be delayed or discontinued during the COVID-19 pandemic unless a patient is suspected or confirmed to have COVID-19.5 Only 1 Food and Drug Administration (FDA)-approved vaccine for the prevention of HZ is available: recombinant zoster vaccine (RZV, Shingrix). According to the Advisory Committee on Immunization Practices (ACIP), RZV is recommended for the prevention of HZ and related complications TABLE. Antiviral Therapies for Herpes Zoster in Adults4 Name
Usual Dosage
Length of Treatment
Acyclovir
800 mg 5 times a day
7-10 days
Famciclovir
500 mg 3 times a day
7 days
Valacyclovir
1000 mg 3 times a day
7 days
All dosages are for oral administration.
Safety and Side Effects
Postlicensure surveillance data on RZV from October 2017 through June 2018 reaffirm that the vaccine is safe and highly effective. Serious adverse events were rare. However, as was seen in clinical trials, local and systemic reactions can occur including pain, swelling, and redness at the injection site as well as fever, chills, and body aches.7 Counseling patients about potential side effects is especially important during the COVID-19 pandemic because some side effects of shingles vaccination may be similar to symptoms of COVID-19.5 These reactions are self-limited and resolve in a few days.8 Because the shingles vaccine stimulates the immune system, patients can expect such reactions to occur. The immune system responses are not a sign of allergy to the vaccination, and patients should not omit the second dose if such reactions occur, especially because the effectiveness of a single dose of RZV has not been studied.7 Reactions to the first dose of the vaccine have not been shown to predict reactions to the second dose. The only contraindication to RZV is a severe allergic reaction to components of the vaccine. Adults with chronic medical conditions including diabetes mellitus, chronic pulmonary disease, and chronic renal failure should receive RZV. The vaccine also is indicated for immunocompromised persons,
22 THE CLINICAL ADVISOR • JULY/AUGUST 2021 • www.ClinicalAdvisor.com
