Well-known singers are reported to be infected! About one-third of the population may be sick, and doing this can prevent it

On the evening of June 28, in the eighth episode of "Singer 2024", Na Ying appeared on the stage with a veil covering half of her face. The reason behind this look is a bit sad: Na Ying was infected with shingles, and the rash grew on her face and eyes.

After the video was exposed, it aroused netizens' attention to shingles. Data shows that about one-third of people will suffer from shingles in their lifetime.

What is shingles?

The "predecessor" of shingles is chickenpox. Varicella-zoster virus (VZV) is a human herpes virus that can cause two different diseases, chickenpox and shingles. After we were infected with chickenpox as children, the varicella-zoster virus can continue to lurk silently in the human body. When our immunity decreases due to aging or internal and external factors such as fatigue and trauma, the virus may be activated, replicated and multiplied again, causing shingles or what the common people call herpes zoster.

Why is shingles becoming more common?

Herpes zoster increases as population ages

The incidence of herpes zoster generally increases with age, rising sharply after the age of 50. A large-scale epidemiological study in Japan reported that the total annual number of herpes zoster cases increased by 54.5% and the average incidence increased by 68.1% in the 21 years since data collection began [1].

The reason why the incidence of shingles increases with age is mainly because the cellular immunity against varicella-zoster virus weakens with age.

Mass varicella vaccination

Large-scale varicella vaccination of children may increase the incidence of herpes zoster at the population level. A study found that although large-scale varicella vaccination can significantly reduce the prevalence of varicella, the incidence of herpes zoster has increased significantly in the 20-49 age group [2].

In other words, people who previously acquired immunity through contact with children with chickenpox may become more susceptible to shingles as their immunity to varicella-zoster decreases due to a decrease in the prevalence of chickenpox.

What are the symptoms of shingles?

Patients with shingles will develop a rash on their skin, and will feel pain, itching or tingling at the site of the rash. According to patients, these pains feel like cutting, burning, electric shock, and whiplash, and the pain is no less than giving birth.

The rash usually settles in a specific area of ​​the body, often along the rib cage on the back or on the face. Interestingly, it seems to be very well behaved, rarely crossing the "line" down the middle of the body, and generally heals within 2 to 4 weeks.

Clinical manifestations of herpes zoster, source: The Journal of dermatology

However, what is troubling is that even after the rash heals, persistent pain and paresthesia may persist for a long time, which is called "postherpetic neuralgia". This condition is more common in severe cases and the elderly [3].

Everyone also noticed that Na Ying's herpes had grown into her eyes. This is also a common consequence of herpes zoster - ophthalmic herpes zoster, which can cause serious vision damage. It is said that 6%-10% of patients suffer from decreased vision due to ophthalmic herpes zoster[3].

Overall, the symptoms of shingles are usually obvious, and an accurate clinical diagnosis can be made once the rash appears.

What medications are used to treat shingles?

Traditional oral anti-herpes virus drugs

Currently, the main oral drugs used to treat herpes zoster are: acyclovir, valacyclovir and famciclovir. These traditional anti-herpes virus drugs can show antiviral activity by inhibiting the synthesis of viral DNA.

Since these drugs are excreted through the kidneys, high blood drug concentrations in patients with renal insufficiency may lead to neuropsychiatric symptoms such as impaired consciousness. Therefore, the use of these antiviral drugs requires dose adjustment based on renal function.

New oral anti-herpes virus drugs

In 2017, amenavir was introduced as a new oral drug for the treatment of herpes zoster [4]. Unlike traditional anti-herpes virus drugs that are nucleic acid analogs, this drug has a novel mechanism that inhibits the helicase-primase complex of VZV.

The helicase-primase complex plays a key role in viral DNA replication. By inhibiting the activity of this enzyme, amenavir blocks viral DNA synthesis and inhibits viral replication.

The drug's antiviral activity is more than 10 times higher than traditional drugs, and once-daily dosing is clinically equivalent to three-times-daily dosing of valacyclovir.

In addition, this drug is mainly excreted through the feces, which is different from the excretion route of traditional drugs, so there is no need to adjust the dose based on renal function.

Considering that the elderly are a high-risk group for herpes zoster and are often accompanied by renal function decline with aging, amenavir may be a treatment option for these patients.

How to prevent shingles ? Strengthen your immune system

It has long been believed that a decrease in immunity to the varicella-zoster virus is one of the triggers of the disease.

The immune response to varicella-zoster virus infection involves humoral immunity and cell-mediated immunity. Studies have shown that varicella-zoster virus-specific cell-mediated immunity plays an important role in preventing the occurrence and severity of herpes zoster and postherpetic neuralgia, while varicella-zoster virus-specific humoral immunity has no effect on preventing herpes zoster or postherpetic neuralgia [3].

Therefore, medical researchers believe that the prevention of shingles can start with enhancing the varicella-zoster virus-specific cellular immune function.

Get the chickenpox vaccine

The varicella vaccine not only prevents the initial varicella infection, but also prevents shingles to a certain extent.

A 2003 study showed that varicella vaccination in people aged 50-79 years enhanced varicella-zoster virus-specific cellular immunity, suggesting that the vaccine may also help prevent herpes zoster [5].

The varicella vaccine is a great way to kill two birds with one stone. A study of more than 30,000 participants aged 60 and above showed that varicella vaccination reduced the incidence of herpes zoster by 51.3% and the incidence of postherpetic neuralgia by 66.5%[6].

The preventive effect of a varicella vaccine (Zostavax live attenuated vaccine). The cumulative incidence of herpes zoster (a) and postherpetic neuralgia (b) was significantly reduced after vaccination with Zostavax. Source: The Journal of dermatology

In Japan, the same vaccine used to prevent chickenpox in children was approved for use in March 2016 to prevent shingles in people 50 years and older. However, there is currently no varicella vaccine approved for use in adults to prevent shingles in the country.

Getting the shingles vaccine

Compared with the varicella vaccine, the herpes zoster vaccine may be more effective in preventing herpes zoster. A trial of more than 15,000 healthy subjects aged 50 years and over showed that the incidence of herpes zoster was reduced by 97.2% after two doses of vaccination (intramuscular injection)[7].

The preventive effect of a shingles vaccine (Shinglix). The cumulative incidence of herpes zoster (a) and postherpetic neuralgia (b) was significantly reduced after Shinglix vaccination. Source: The Journal of dermatology

At present, both domestic and international expert guidelines recommend vaccination with the herpes zoster vaccine as a primary preventive measure for herpes zoster. In March 2022, the Chinese Medical Journal published my country’s first “Expert Consensus on Herpes Zoster Vaccination”, which clearly recommends vaccination with the herpes zoster vaccine for people aged 50 years and above with normal immune function[8].

In January 2023, the domestically produced shingles vaccine was launched on the market, becoming the first live attenuated shingles vaccine suitable for people aged 40 and above in China. Only one shot of this vaccine is needed to provide more than 10 years of immunity. With the continuous access across the country, the majority of people of appropriate age can receive the domestically produced shingles vaccine at nearby vaccination clinics.

If you're concerned about your risk of shingles, talk to your doctor about whether you're a candidate for a specific shingles vaccine.

References:

[1] Toyama N. “Invasive meningococcal infection, April 2013-October 2017”, Japan. IASR. 2018;39:139–41

[2] Toyama, Nozomu et al. “Universal varicella vaccination increased the incidence of herpes zoster in the child-rearing generation as its short-term effect.” Journal of dermatological science vol. 92,1 (2018): 89-96. doi:10.1016/j.jdermsci.2018.07.003

[3] Hakami, Mohammed Ageeli et al. “Varicella-zoster virus-related neurological complications: From infection to immunomodulatory therapies.” Reviews in medical virology vol. 34,4 (2024): e2554. doi:10.1002/rmv.2554

[4] Asada, Hideo. “Recent topics in the management of herpes zoster.” The Journal of dermatology vol. 50,3 (2023): 305-310. doi:10.1111/1346-8138.16666

[5] Takahashi, Michiaki et al. “Enhancement of immunity against VZV by giving live varicella vaccine to the elderly assessed by VZV skin test and IAHA, gpELISA antibody assay.” Vaccine vol. 21,25-26 (2003): 3845-53. doi:10.1016/s0264-410x(03)00303-7

[6] Oxman, MN et al. “A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults.” The New England journal of medicine vol. 352,22 (2005): 2271-84. doi:10.1056/NEJMoa051016

[7] Lal, Himal et al. “Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults.” The New England journal of medicine vol. 372,22 (2015): 2087-96. doi:10.1056/NEJMoa1501184

[8] Dermatology Branch of China Association for International Exchange of Medical Care, and Research Center for Geriatric Dermatology of Chinese Medical Association Dermatology and Venereology. "Expert consensus on shingles vaccination." Chinese Medical Journal 102.8(2022):6.