Varicella vaccine

(Redirected from Chickenpox vaccine)

Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox.[9] One dose of vaccine prevents 95% of moderate disease and 100% of severe disease.[10] Two doses of vaccine are more effective than one.[10] If given to those who are not immune within five days of exposure to chickenpox it prevents most cases of disease.[10] Vaccinating a large portion of the population also protects those who are not vaccinated.[10] It is given by injection just under the skin.[10] Another vaccine, known as zoster vaccine, is used to prevent diseases caused by the same virus – the varicella zoster virus.[11]

Varicella vaccine
Varicella vaccine
Vaccine description
TargetVaricella
Vaccine typeAttenuated
Clinical data
Trade namesVarivax, Varilrix, others
AHFS/Drugs.comMonograph
MedlinePlusa607029
Pregnancy
category
Routes of
administration
subcutaneous
ATC code
Legal status
Legal status
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CAS Number
DrugBank
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The World Health Organization (WHO) recommends routine vaccination only if a country can keep more than 80% of people vaccinated.[10] If only 20% to 80% of people are vaccinated it is possible that more people will get the disease at an older age and outcomes overall may worsen.[10] Either one or two doses of the vaccine is recommended.[10] In the United States two doses are recommended starting at twelve to fifteen months of age.[9] As of 2017, twenty-three countries recommend all non-medically exempt children receive the vaccine, nine recommend it only for high risk groups, three additional countries recommend use in only parts of the country, while other countries make no recommendation.[12] Not all countries provide the vaccine due to its cost.[13] In the United Kingdom, Varilrix, a live viral vaccine[14] is approved from the age of 12 months, but only recommended for certain at risk groups.

Minor side effects may include pain at the site of injection, fever, and rash.[9] Severe side effects are rare and occur mostly in those with poor immune function.[10] Its use in people with HIV/AIDS should be done with care.[10] It is not recommended during pregnancy; however, the few times it has been given during pregnancy no problems resulted.[9][10] The vaccine is available either by itself or along with the MMR vaccine, in a version known as the MMRV vaccine.[10] It is made from weakened virus.[9]

A live attenuated varicella vaccine, the Oka strain, was developed by Michiaki Takahashi and his colleagues in Japan in the early 1970s.[15] American vaccinologist Maurice Hilleman's team developed a chickenpox vaccine in the United States in 1981, based on the "Oka strain" of the varicella virus.[16][17][18] The chickenpox vaccine first became commercially available in 1984.[10] It is on the WHO Model List of Essential Medicines.[19][20]

Medical uses

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Varicella vaccine is 70% to 90% effective for preventing varicella and more than 95% effective for preventing severe varicella.[21] Follow-up evaluations have taken place in the United States of children immunized that revealed protection for at least 11 years. Studies were conducted in Japan which indicated protection for at least 20 years.[21]

People who do not develop enough protection when they get the vaccine may develop a mild case of the disease when in close contact with a person with chickenpox. In these cases, people show very little sign of illness.[22] This has been the case of children who get the vaccine in their early childhood and later have contact with children with chickenpox. Some of these children may develop a mild chickenpox also known as breakthrough disease.[23]

Another vaccine, known as zoster vaccine, is simply a larger-than-normal dose of the same vaccine used against chickenpox, and is used in older adults to reduce the risk of shingles (also called herpes zoster) and postherpetic neuralgia, which are caused by the same virus.[11] The recombinant zoster (shingles) vaccine is recommended for adults aged 50 years and older.[24]

Duration of immunity

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The long-term duration of protection from varicella vaccine is unknown, but there are now persons vaccinated twenty years ago with no evidence of waning immunity, while others have become vulnerable in as few as six years. Assessments of duration of immunity are complicated in an environment where natural disease is still common, which typically leads to an overestimation of effectiveness.[25]

Some vaccinated children have been found to lose their protective antibody in as little as five to eight years.[26] However, according to the World Health Organization (WHO): "After observation of study populations for periods of up to 20 years in Japan and 10 years in the United States, more than 90% of immunocompetent persons who were vaccinated as children were still protected from varicella." However, since only one out of five Japanese children were vaccinated, the annual exposure of these vaccinees to children with natural chickenpox boosted the vaccinees' immune system. In the United States, where universal varicella vaccination has been practiced, the majority of children no longer receive exogenous (outside) boosting, thus, their cell-mediated immunity to VZV (varicella zoster virus) wanes – necessitating booster chickenpox vaccinations.[27] As time goes on, boosters may be necessary. Persons exposed to the virus after vaccination tend to experience milder cases of chickenpox if they develop the disease.[28]

Chickenpox

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Shows gradual decline of varicella-related deaths as underlying cause after introduction of Varicella Vaccine in 1995 in the United States. Data obtained from “Decline in mortality due to varicella after implementation of varicella vaccination in the United States”(Nguyen et al., 2005)

Prior to the widespread introduction of the vaccine in the United States in 1995 (1986 in Japan and 1988 in Korea[29]), there were around 4,000,000 cases per year in the United States, mostly in children, with typically 10,500–13,000 hospital admissions (range, 8,000–18,000), and 100–150 deaths each year.[29][27][10][30] Most of the deaths were among young children.[31]

During 2003, and the first half of 2004, the CDC reported eight deaths from varicella, six of whom were children or adolescents. These deaths and hospital admissions have substantially declined in the US due to vaccination,[32][33] though the rate of shingles infection has increased as adults are less exposed to infected children (which would otherwise help protect against shingles).[34][35][36] Ten years after the vaccine was recommended in the US, the CDC reported as much as a 90% drop in chickenpox cases, a varicella-related hospital admission decline of 71%[30] and a 97% drop in chickenpox deaths among those under 20.[37]

Vaccines are less effective among high-risk patients, as well as being more dangerous because they contain attenuated live virus. In a study performed on children with an impaired immune system, 30% had lost the antibody after five years, and 8% had already caught wild chickenpox in that five-year period.[38]

Herpes zoster

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Herpes zoster (shingles) most often occurs in the elderly and is only rarely seen in children. The incidence of herpes zoster in vaccinated adults is 0.9/1000 person-years, and is 0.33/1000 person-years in vaccinated children; this is lower than the overall incidence of 3.2–4.2/1000 person-years.[39][40]

The risk of developing shingles is reduced for children who receive the varicella vaccine, but not eliminated.[41] The CDC stated in 2014: "Chickenpox vaccines contain weakened live VZV, which may cause latent (dormant) infection. The vaccine-strain VZV can reactivate later in life and cause shingles. However, the risk of getting shingles from vaccine-strain VZV after chickenpox vaccination is much lower than getting shingles after natural infection with wild-type VZV."[42]

The risk of shingles is significantly lower among children who have received varicella vaccination, including those who are immunocompromised. The risk of shingles is approximately 80% lower among healthy vaccinated children compared to unvaccinated children who had wild-type varicella.[41][43] A population with high varicella vaccination also has lower incidence of shingles in unvaccinated children, due to herd immunity.[43]

Schedule

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The WHO recommends one or two doses with the initial dose given at 12 to 18 months of age.[10] The second dose, if given, should occur at least one to three months later.[10] The second dose, if given, provides the additional benefit of improved protection against all varicella.[44] This vaccine is a shot given subcutaneously (under the skin). It is recommended for all children under 13 and for everyone 13 or older who has never had chickenpox.[45]

In the United States, two doses are recommended by the CDC. For a routine vaccination, the first dose is administered at 12 to 15 months of age and a second dose at age 4–6 years. However, the second dose can be given as early as 3 months after the first dose. If an individual misses the timing for the routine vaccination, the individual is eligible to receive a catch-up vaccination. For a catch-up vaccination, individuals between 7 and 12 years old should receive a two-dose series 3 months apart (a minimum interval of 4 weeks). For individuals 13–18 years old, the catch-up vaccination should be given 4 to 8 weeks apart (a minimum interval of 4 weeks).[46] The varicella vaccine did not become widely available in the United States until 1995.[47]

In the UK, the vaccine is only available on the National Health Service for those who are in close contact with someone who is particularly vulnerable to chickenpox.[48] As there is an increased risk of shingles in adults due to possible lack of contact with chickenpox-infected children providing a natural boosting to immunity, and the fact that chickenpox is usually a mild illness, the NHS cites concerns about unvaccinated children catching chickenpox as adults when it is more dangerous.[48] However, the vaccine is approved for 12 months and up and is available privately, with a second dose to be given a year after the first.[14]

Contraindications

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The varicella vaccine is not recommended for seriously ill people, pregnant women, people who have tuberculosis, people who have experienced a serious allergic reaction to the varicella vaccine in the past, people who are allergic to gelatin, people allergic to neomycin, people receiving high doses of steroids, people receiving treatment for cancer with x-rays or chemotherapy, as well as people who have received blood products or transfusions during the past five months.[49][50] Additionally, the varicella vaccine is not recommended for people who are taking salicylates (e.g. aspirin).[50] After receiving the varicella vaccine, the use of salicylates should be avoided for at least six weeks.[50] The varicella vaccine is also not recommended for individuals who have received a live vaccine in the last four weeks,[50] because live vaccines that are administered too soon within one another may not be as effective.[50] It may be usable in people with HIV infections who have a good blood count and are receiving appropriate treatment.[10] Specific antiviral medication, such as acyclovir, famciclovir, or valacyclovir, are not recommended 24 hours before and 14 days after vaccination.[51]

Side effects

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Serious side effects are very rare. From 1998 to 2013, only one vaccine-related death was reported: an English child with pre-existent leukemia. On some occasions, severe reactions such as meningitis and pneumonia have been reported (mainly in inadvertently vaccinated immunocompromised children) as well as anaphylaxis.[39]

The possible mild side effects include redness, stiffness, and soreness at the injection site, as well as fever. A few people may develop a mild rash, which usually appears around the injection site.[52]

There is a short-term risk of developing herpes zoster (shingles) following vaccination. However, this risk is less than the risk due to a natural infection resulting in chickenpox.[53]: 378  Most of the cases reported have been mild and have not been associated with serious complications.[54]

Approximately 5% of children who receive the vaccine develop a fever or rash. Adverse reaction reports for the period 1995 to 2005 found no deaths attributed to the vaccine despite approximately 55.7 million doses being delivered.[55] Cases of vaccine-related chickenpox have been reported in patients with a weakened immune system,[56][57] but no deaths.

The literature contains several reports of adverse reactions following varicella vaccination, including vaccine-strain zoster in children and adults.[58]

History

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The varicella zoster vaccine is made from the Oka/Merck strain of live attenuated varicella virus. The Oka virus was initially obtained from a child with natural varicella, introduced into human embryonic lung cell cultures, adapted to and propagated in embryonic guinea pig cell cultures, and finally propagated in a human diploid cell line originally derived from fetal tissues (WI-38).[4][5][6] Takahashi and his colleagues used the Oka strain to develop a live attenuated varicella vaccine in Japan in the early 1970s.[15] This strain was further developed by pharmaceutical companies such as Merck & Co. and GlaxoSmithKline.[59] American vaccinologist Maurice Hilleman's team at Merck then used the Oka strain to prepare a chickenpox vaccine in 1981.[16][17][18]

Japan was among the first countries to vaccinate for chickenpox. The vaccine developed by Hilleman was first licensed in the United States in 1995.[16][60] Routine vaccination against varicella zoster virus is also performed in the United States, and the incidence of chickenpox has been dramatically reduced there (from four million cases per year in the pre-vaccine era to approximately 390,000 cases per year as of 2014).[61]

As of 2019, standalone varicella vaccines are available in all 27 European Union member countries, and 16 countries also offer a combined measles, mumps, rubella and varicella vaccine (MMRV).[62] Twelve European countries (Austria, Andorra, Cyprus, Czech Republic, Finland, Germany, Greece, Hungary, Italy, Latvia, Luxembourg and Spain) have universal varicella vaccination (UVV) policies, though only six of these countries have made it available at no cost via government funding.[62] EU member states that have not implemented UVV cite reasons such as "a perceived low disease burden and low public health priority," the cost and cost-effectiveness, the possible risk of herpes zoster when vaccinating older adults, and rare fevers leading to seizures after the first dose of the MMRV vaccine.[62] "Countries that implemented UVV experienced decreases in varicella incidence, hospitalizations and complications, showing overall beneficial impact."[62]

Varicella vaccination is recommended in Canada for all healthy children aged 1 to 12, as well as susceptible adolescents and adults 50 years of age and younger; "may be considered for people with select immunodeficiency disorders;[22] and "should be prioritized" for susceptible individuals, including "non-pregnant women of childbearing age, household contacts of immunocompromised individuals, members of a household expecting a newborn, health care workers, adults who may be exposed occupationally to varicella (for example, people who work with young children), immigrants and refugees from tropical regions, people receiving chronic salicylate therapy (for example, acetylsalicylic acid [ASA])," and others.[63]

Australia has adopted recommendations for routine immunization of children and susceptible adults against chickenpox.[64]

Other countries, such as the United Kingdom, have targeted recommendations for the vaccine, e.g., for susceptible health care workers at risk of varicella exposure. In the UK, varicella antibodies are measured as part of the routine of prenatal care, and by 2005 all National Health Service personnel had determined their immunity and been immunized if they were non-immune and have direct patient contact. Population-based immunization against varicella is not otherwise practised in the UK.[65]

Since 2013, the MMRV vaccine is offered for free to all Brazilian citizens.[66]

Society and culture

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Catholic Church

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The Roman Catholic Church is opposed to abortion. Nevertheless, the Pontifical Academy for Life stated in 2017 that "clinically recommended vaccinations can be used with a clear conscience and that the use of such vaccines does not signify some sort of cooperation with voluntary abortion".[67] On 21 December 2020, the Vatican's doctrinal office, the Congregation for the Doctrine of the Faith, further clarified that it is "morally licit" for Catholics to receive vaccines derived from fetal cell lines or in which such lines were used in testing or development, because "passive material cooperation in the procured abortion from which these cell lines originate is, on the part of those making use of the resulting vaccines, remote" and "does not and should not in any way imply that there is a moral endorsement of the use of cell lines proceeding from aborted fetuses".[68]

References

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  1. ^ "Varicella virus vaccine (Varivax) Use During Pregnancy". Drugs.com. 6 February 2019. Archived from the original on 23 October 2019. Retrieved 28 December 2019.
  2. ^ "Varivax – Summary of Product Characteristics (SmPC)". (emc). 29 November 2018. Archived from the original on 7 March 2022. Retrieved 28 December 2019.
  3. ^ "Varilrix 10 3.3 PFU/0.5ml, powder and solvent for solution for injection – Summary of Product Characteristics (SmPC)". (emc). 20 February 2020. Archived from the original on 26 January 2021. Retrieved 27 February 2021.
  4. ^ a b "Varivax – varicella virus vaccine live injection, powder, lyophilized, for suspension". DailyMed. Archived from the original on 24 March 2021. Retrieved 27 February 2021.
  5. ^ a b "Varivax". U.S. Food and Drug Administration (FDA). 16 September 2020. Archived from the original on 7 March 2021. Retrieved 27 February 2021.
  6. ^ a b "Varivax". U.S. Food and Drug Administration (FDA). 22 July 2017. Archived from the original on 22 July 2017. Retrieved 8 March 2023.
  7. ^ "Varilrix". European Medicines Agency (EMA). 26 June 2020. Archived from the original on 1 March 2021. Retrieved 27 February 2021.
  8. ^ "List of nationally authorised medicinal products" (PDF). ema.europa.eu. 27 October 2022. Archived (PDF) from the original on 29 May 2024. Retrieved 23 April 2023.
  9. ^ a b c d e "Chickenpox (Varicella) Vaccine Safety". Centers for Disease Control and Prevention (CDC). 27 October 2015. Archived from the original on 22 December 2015. Retrieved 15 December 2015.
  10. ^ a b c d e f g h i j k l m n o p q "Varicella and herpes zoster vaccines: WHO position paper, June 2014". Relevé Épidémiologique Hebdomadaire. 89 (25): 265–287. June 2014. hdl:10665/242227. PMID 24983077.
  11. ^ a b "Herpes Zoster Vaccination". Centers for Disease Control and Prevention. 31 July 2015. Archived from the original on 26 October 2021. Retrieved 26 October 2021.
  12. ^ Wutzler P, Bonanni P, Burgess M, Gershon A, Sáfadi MA, Casabona G (August 2017). "Varicella vaccination - the global experience". Expert Review of Vaccines. 16 (8): 833–843. doi:10.1080/14760584.2017.1343669. PMC 5739310. PMID 28644696.
  13. ^ Flatt A, Breuer J (September 2012). "Varicella vaccines". British Medical Bulletin. 103 (1): 115–127. doi:10.1093/bmb/lds019. PMID 22859715.
  14. ^ a b "Varilrix". Archived from the original on 28 July 2023. Retrieved 21 November 2021.
  15. ^ a b Gershon AA (2007). "Varicella-zoster vaccine". In Arvin A, Campadelli-Fiume G, Mocarski E, Moore PS (eds.). Human Herpesviruses: Biology, Therapy, and Immunoprophylaxis. Cambridge: Cambridge University Press. ISBN 978-0521827140. PMID 21348127. Archived from the original on 23 November 2020. Retrieved 6 February 2021.
  16. ^ a b c Schillie S, Vellozzi C, Reingold A, Harris A, Haber P, Ward JW, Nelson NP (January 2018). "Prevention of Hepatitis B Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices". MMWR. Recommendations and Reports. 67 (1): 443–470. doi:10.1016/B978-0-12-804571-8.00003-2. ISBN 9780128045718. PMC 7150172. PMID 29939980.
  17. ^ a b "Chickenpox (Varicella)". History of Vaccines. Archived from the original on 22 January 2021. Retrieved 6 February 2021.
  18. ^ a b "Maurice Ralph Hilleman (1919–2005)". The Embryo Project Encyclopedia. Archived from the original on 27 August 2017. Retrieved 6 February 2021.
  19. ^ World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  20. ^ World Health Organization (2021). World Health Organization model list of essential medicines: 22nd list (2021). Geneva: World Health Organization. hdl:10665/345533. WHO/MHP/HPS/EML/2021.02.
  21. ^ a b Committee on Infectious Diseases (July 2007). "Prevention of varicella: recommendations for use of varicella vaccines in children, including a recommendation for a routine 2-dose varicella immunization schedule". Pediatrics. 120 (1): 221–231. doi:10.1542/peds.2007-1089. PMID 17606582.
  22. ^ a b "Chickenpox (Varicella) Vaccination". www.cdc.gov. 25 February 2021. Archived from the original on 12 December 2018. Retrieved 27 April 2022.
  23. ^ "Varicella Vaccine (Chickenpox)". Archived from the original on 15 March 2010. Retrieved 5 May 2010.
  24. ^ "Recombinant Shingles VIS". U.S. Centers for Disease Control and Prevention (CDC). February 2022. Archived from the original on 23 October 2019. Retrieved 22 October 2019.
  25. ^ Goldman GS (2005). "Universal varicella vaccination: efficacy trends and effect on herpes zoster". International Journal of Toxicology. 24 (4): 205–213. CiteSeerX 10.1.1.540.9230. doi:10.1080/10915810591000659. PMID 16126614. S2CID 34310228.
  26. ^ Chaves SS, Gargiullo P, Zhang JX, Civen R, Guris D, Mascola L, Seward JF (March 2007). "Loss of vaccine-induced immunity to varicella over time". The New England Journal of Medicine. 356 (11): 1121–1129. doi:10.1056/NEJMoa064040. PMID 17360990.
  27. ^ a b The Vaccines and other Biologicals department (May 2003). "Varicella vaccine". World Health Organization (WHO). Archived from the original on 13 August 2006. Retrieved 18 August 2006.
  28. ^ "General questions about the disease". Varicella Disease (Chickenpox). CDCP. 20 December 2001. Archived from the original on 25 August 2006. Retrieved 18 August 2006.
  29. ^ a b Takahashi M (2001). "25 years' experience with the Biken Oka strain varicella vaccine: a clinical overview". Paediatric Drugs. 3 (4): 285–292. doi:10.2165/00128072-200103040-00005. PMID 11354700. S2CID 25328919.
  30. ^ a b Lopez A, Schmid S, Bialek S (2011). "Chapter 17: Varicella". In Roush SW, McIntyre L, Baldy LM (eds.). Manual for the surveillance of vaccine-preventable diseases (5th ed.). Atlanta GA: Centers for Disease Control and Prevention (CDC). Archived from the original on 25 April 2012.
  31. ^ Altman L (18 March 1995). "After Long Debate, Vaccine For Chicken Pox Is Approved". New York Times. Archived from the original on 29 September 2021. Retrieved 29 September 2021. Up to 100 deaths occur from chicken pox each year, and most of the victims are young children.
  32. ^ Seward JF, Watson BM, Peterson CL, Mascola L, Pelosi JW, Zhang JX, et al. (February 2002). "Varicella disease after introduction of varicella vaccine in the United States, 1995–2000". JAMA. 287 (5): 606–611. doi:10.1001/jama.287.5.606. PMID 11829699.
  33. ^ Nguyen HQ, Jumaan AO, Seward JF (February 2005). "Decline in mortality due to varicella after implementation of varicella vaccination in the United States". The New England Journal of Medicine. 352 (5): 450–458. doi:10.1056/NEJMoa042271. PMID 15689583.
  34. ^ Patel MS, Gebremariam A, Davis MM (December 2008). "Herpes zoster-related hospitalizations and expenditures before and after introduction of the varicella vaccine in the United States". Infection Control and Hospital Epidemiology. 29 (12): 1157–1163. doi:10.1086/591975. PMID 18999945. S2CID 21934553.
  35. ^ Yih WK, Brooks DR, Lett SM, Jumaan AO, Zhang Z, Clements KM, Seward JF (June 2005). "The incidence of varicella and herpes zoster in Massachusetts as measured by the Behavioral Risk Factor Surveillance System (BRFSS) during a period of increasing varicella vaccine coverage, 1998–2003". BMC Public Health. 5: 68. doi:10.1186/1471-2458-5-68. PMC 1177968. PMID 15960856.
  36. ^ Yawn BP, Saddier P, Wollan PC, St Sauver JL, Kurland MJ, Sy LS (November 2007). "A population-based study of the incidence and complication rates of herpes zoster before zoster vaccine introduction". Mayo Clinic Proceedings. 82 (11): 1341–1349. doi:10.4065/82.11.1341. PMID 17976353.
  37. ^ Szabo L (25 July 2011). "Vaccine has nearly eliminated chickenpox deaths in children". USA Today. Archived from the original on 26 September 2011. Retrieved 15 November 2011.
  38. ^ Pirofski LA, Casadevall A (January 1998). "Use of licensed vaccines for active immunization of the immunocompromised host". Clinical Microbiology Reviews. 11 (1): 1–26. doi:10.1128/CMR.11.1.1. PMC 121373. PMID 9457426.
  39. ^ a b Gershon AA (January 2013). "Varicella zoster vaccines and their implications for development of HSV vaccines". Virology. 435 (1): 29–36. doi:10.1016/j.virol.2012.10.006. PMC 3595154. PMID 23217613.
  40. ^ Harpaz R, Ortega-Sanchez IR, Seward JF (June 2008). "Prevention of herpes zoster: recommendations of the Advisory Committee on Immunization Practices (ACIP)" (PDF). MMWR. Recommendations and Reports. 57 (RR-5): 1–30, quiz CE2–4. PMID 18528318. Archived (PDF) from the original on 8 June 2021. Retrieved 9 October 2020.
  41. ^ a b "Chickenpox (Varicella) for Healthcare Professionals". Centers for Disease Control and Prevention. 21 October 2022. Archived from the original on 6 December 2011. Retrieved 8 March 2023.
  42. ^ "CDC – Varicella Vaccine – Vaccine Safety". Centers for Disease Control and Prevention (CDC). Archived from the original on 25 August 2015.
  43. ^ a b Haelle T (October 2019). "Two-for-One: Chickenpox Vaccine Lowers Shingles Risk in Children - Immunization reduces the likelihood of a painful reemergence of the virus in kids". Scientific American. Archived from the original on 20 February 2020. Retrieved 8 March 2023.
  44. ^ Marin M, Marti M, Kambhampati A, Jeram SM, Seward JF (March 2016). "Global Varicella Vaccine Effectiveness: A Meta-analysis". Pediatrics. 137 (3): e20153741. doi:10.1542/peds.2015-3741. PMID 26908671. Archived from the original on 2 August 2019. Retrieved 2 August 2019.
  45. ^ "Chickenpox Vaccination: What Everyone Should Know". Centers for Disease Control and Prevention (CDC). 7 August 2019. Archived from the original on 22 October 2021. Retrieved 26 October 2021.
  46. ^ "Recommended Child and Adolescent Immunization Schedule for ages 18 years or younger, United States, 2019". Centers for Disease Control and Prevention (CDC). 5 February 2019. Archived from the original on 6 March 2016. Retrieved 2 August 2019.
  47. ^ "Monitoring the Impact of Varicella Vaccination". Centers for Disease Control and Prevention (CDC). 1 July 2016. Archived from the original on 17 June 2017. Retrieved 14 July 2017.
  48. ^ a b "Chickenpox vaccine FAQs". NHS website for England. 31 July 2019. Archived from the original on 12 April 2020. Retrieved 4 July 2022.
  49. ^ "Who should not receive the varicella vaccine?". Archived from the original on 15 June 2010. Retrieved 5 May 2010.
  50. ^ a b c d e "Chickenpox VIS". Centers for Disease Control and Prevention (CDC). 15 August 2019. Archived from the original on 7 May 2019. Retrieved 3 March 2023.
  51. ^ "General Best Practice Guidelines for Immunization: Contraindications and Precautions" (PDF). Archived (PDF) from the original on 29 January 2019. Retrieved 29 January 2019.
  52. ^ "What side effects have been reported with this vaccine?". Archived from the original on 4 May 2010. Retrieved 5 May 2010.
  53. ^ James WD, Berger TG, et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 978-0721629216.
  54. ^ "Vaccine Information for the public and health professionals". Archived from the original on 4 May 2010. Retrieved 5 May 2010.
  55. ^ Galea SA, Sweet A, Beninger P, Steinberg SP, Larussa PS, Gershon AA, Sharrar RG (March 2008). "The safety profile of varicella vaccine: a 10-year review". The Journal of Infectious Diseases. 197 (Supplement 2): S165–S169. doi:10.1086/522125. hdl:2027.42/61293. PMID 18419392. S2CID 25145408.
  56. ^ Wise RP, Salive ME, Braun MM, Mootrey GT, Seward JF, Rider LG, Krause PR (September 2000). "Postlicensure safety surveillance for varicella vaccine". JAMA. 284 (10): 1271–1279. doi:10.1001/jama.284.10.1271. PMID 10979114.
  57. ^ Quinlivan MA, Gershon AA, Nichols RA, La Russa P, Steinberg SP, Breuer J (April 2006). "Vaccine Oka varicella-zoster virus genotypes are monomorphic in single vesicles and polymorphic in respiratory tract secretions". The Journal of Infectious Diseases. 193 (7): 927–930. doi:10.1086/500835. PMID 16518753.
  58. ^ For example:
  59. ^ Tillieux SL, Halsey WS, Thomas ES, Voycik JJ, Sathe GM, Vassilev V (November 2008). "Complete DNA sequences of two oka strain varicella-zoster virus genomes". Journal of Virology. 82 (22): 11023–11044. doi:10.1128/JVI.00777-08. PMC 2573284. PMID 18787000.
  60. ^ "Varicella (chickenpox): Questions and Answers" (PDF). Archived (PDF) from the original on 2 October 2018. Retrieved 23 April 2023.
  61. ^ Lopez AS, Zhang J, Marin M (September 2016). "Epidemiology of Varicella During the 2-Dose Varicella Vaccination Program - United States, 2005-2014". MMWR. Morbidity and Mortality Weekly Report. 65 (34): 902–905. doi:10.15585/mmwr.mm6534a4. PMID 27584717.
  62. ^ a b c d Spoulou V, Alain S, Gabutti G, Giaquinto C, Liese J, Martinon-Torres F, Vesikari T (February 2019). "Implementing Universal Varicella Vaccination in Europe: The Path Forward". The Pediatric Infectious Disease Journal. 38 (2): 181–188. doi:10.1097/INF.0000000000002233. hdl:11392/2400466. PMID 30408002. S2CID 53239234.
  63. ^ "Varicella (chickenpox) vaccine: Canadian Immunization Guide For health professionals". Canadian Immunization Guide. Health Canada. July 2018. Archived from the original on 21 September 2021. Retrieved 3 October 2021.
  64. ^ "Chickenpox immunisation service (Link invalid)". health.gov.au. 15 April 2021. Archived from the original on 26 October 2021. Retrieved 26 October 2021.
  65. ^ "Chickenpox vaccine FAQs". NHS.uk. 31 July 2019. Archived from the original on 12 April 2020. Retrieved 1 April 2020.
  66. ^ Scotta MC, Paternina-de la Ossa R, Lumertz MS, Jones MH, Mattiello R, Pinto LA (January 2018). "Early impact of universal varicella vaccination on childhood varicella and herpes zoster hospitalizations in Brazil". Vaccine. 36 (2): 280–284. doi:10.1016/j.vaccine.2017.11.057. PMID 29198917.
  67. ^ "Note on Italian vaccine issue". www.academyforlife.va. Archived from the original on 21 February 2023. Retrieved 3 October 2021.
  68. ^ Congregation for the Doctrine of the Faith (21 December 2020). "Note of the Congregation for the Doctrine of the Faith on the morality of using some anti-Covid-19 vaccines, 21.12.2020". Summary of Bulletin, Holy See Press Office. Holy See. Archived from the original on 3 October 2021. Retrieved 3 October 2021.

Further reading

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