What causes chickenpox and how can you get it?
Chickenpox (varicella) is caused by a DNA virus [2, 3] called varicella zoster virus (VZV) [1, 2, 3, 4]. VZV can spread in the air [1, 2, 3, 4], but direct contact is also a route of infection [1, 2, 3]. After the virus enters the body, a so-called latency period lasts for about 14 days [1]. During this period the virus spreads inside the body (primary viremia), then replicates further (secondary viremia), infecting the skin [1, 2]. Malaise or fever may occur [1, 2, 3] before the itchy skin rash appears [2, 3].
What about vaccines?
VZV infection usually leads to lifelong immunity, although in rare cases, a second chickenpox attack can happen [2, 3]. For immunization, monovalent and combined (with measles, mumps, rubella) preventive vaccines are available [2, 3, 4]. Vaccination appears to provide long-lasting immunity [2]. Although breakthrough infection may occur, it is usually accompanied with milder symptoms than the ones caused by chickenpox in unvaccinated individuals [2].
Image source [6]: https://pixabay.com/vectors/syringe-vaccination-injection-5801045/
Are there any complications of chickenpox?
In healthy children, chickenpox is mostly benign [2, 3, 4], but the severity can increase with age [1, 2, 3]. Possible complications include secondary bacterial infections, pneumonia, and neurological manifestations, among others [1, 2, 3, 4]. Vaccination can decrease the risk for all these chickenpox-related complications in the population [2, 4].
If you want to learn more about chickenpox, you will find many useful information on the website of the European Centre for Disease Prevention and Control (ECDC) [5]: https://www.ecdc.europa.eu/en/varicella.
References
1. Brentjens MH, Yeung-Yue KA, Lee PC, Tyring SK. Vaccines for viral diseases with dermatologic manifestations. Dermatol Clin. 2003;21(2):349-369. doi:10.1016/s0733-8635(02)00098-0
2. Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. Hamborsky J, Kroger A, Wolfe S, eds. 13th ed. Washington D.C. Public Health Foundation, 2015. p.353-376.
3. Varicella and herpes zoster vaccines: WHO position paper, June 2014. Wkly Epidemiol Rec. 2014;89(25):265-288.
4. Lo Presti C, Curti C, Montana M, Bornet C, Vanelle P. Chickenpox: An update. Med Mal Infect. 2019;49(1):1-8. doi:10.1016/j.medmal.2018.04.395
5. https://www.ecdc.europa.eu/en/varicella [Accessed on 22 May 2021]
6. https://pixabay.com/vectors/syringe-vaccination-injection-5801045/ [Accessed on 20 May 2021]