Varicella vaccine
Vaccine description
Target disease Varicella (chickenpox), herpes zoster, postherpetic neuralgia, Ramsay Hunt syndrome type II
Type Attenuated virus
Clinical data
MedlinePlus
Legal status
  • Prescription only
Identifiers
CAS number  YesY
ATC code J07
 N   

The varicella vaccine is a health system.[1]

Medical uses

Varicella vaccine is 70% to 90% effective for preventing varicella and more than 95% effective for preventing severe varicella.[2] Furthermore, follow-up evaluations took place in the United States of children immunized that revealed protection for at least 11 years. Also, studies were conducted in Japan which indicated protection for at least 20 years.[2]

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. 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.[3]

Duration of immunity

The long-term duration of protection from varicella vaccine is unknown, but there are now persons vaccinated more than thirty 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.[4]

Some vaccinated children have been found to lose their protective antibody in as little as five to eight years.[5] However, according to the [6] Some persons exposed to the virus after vaccine can experience milder cases of chicken pox (and usually then harbor both the attenuated vaccine or oka strain as well as the wild type or natural chickenpox strain which are both subject to reactivation as shingles).[7]

Catching "wild" chickenpox as a child has been thought to commonly result in lifelong immunity. Indeed, parents have deliberately ensured this in the past with "[9][10][11][12][13]

Immunocompromised patients

The mortality rate in immunocompromised patients with disseminated herpes zoster is 5–15%, with most deaths from pneumonia. Vaccines are less effective among these high-risk patients, as well as being more dangerous because they contain attenuated live virus (see last footnote). 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.[14]

Herpes zoster

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.[15][16]

Adult shingles cases may increase after introduction of varicella vaccine, but evidence is unclear.[16][17][8][18] While research using computer models has tended to support the hypothesis that vaccination programs would increase incidence of zoster in the short term, the evidence from epidemiological studies is mixed,[19][20] and increases observed in zoster incidence in some studies may not be related to vaccination programs, as the incidence increases prior to the varicella vaccine program being initiated.[21]

Regarding herpes zoster, the US Centers for Disease Control states:

"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." [22]

Rates of chickenpox

Prior to the introduction of the vaccine in 1995 in the USA (released in 1988 in Japan & Korea), there were around 4,000,000 cases per year in the US, mostly children, with typically 10,500–13,000 hospital admissions (range, 8,000–18,000), and 100–150 deaths each year.[23][6] Though mostly children caught it, the majority of deaths (by as much as 80%) were among adults.

During 2003 and the first half of 2004, the US Centers for Disease Control and Prevention (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,[24][25] though the rate of shingles infection has increased as adults are less exposed to infected children (which would otherwise help protect against shingles).[26][27][28] Ten years after the vaccine was recommended in the US, the CDC reported as much as a 90% drop in chicken pox cases, a varicella-related hospital admission decline of 71%[23] and a 97% drop in chicken pox deaths among those under 20.[29]

Vaccine

The Varicella Zoster vaccine is made from the Oka/Merck strain of live attenuated varicella virus. The 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 human diploid cell cultures.

Vaccination worldwide

Japan was among the first countries to vaccinate for chickenpox. Routine vaccination against varicella zoster virus is also performed in the United States, and the incidence of chickenpox has been dramatically reduced there (from 4 million cases per year in the pre-vaccine era to approximately 400,000 cases per year as of 2005). In Europe most countries do not currently vaccinate against varicella, though the vaccine is gaining wider acceptance. Australia, Canada, and other countries have now adopted recommendations for routine immunization of children and susceptible adults against chickenpox.

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 practiced in the UK.

Administration

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.

Two doses are always recommended. In the first case a first dose is administered at 12 to 15 months and a second dose at age 4–6 years. For people older than 13 the two doses are administered 4 to 8 weeks apart.[30]

The varicella vaccine is not recommended for seriously ill people, pregnant women, 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 suffering from an immune system disease, such as HIV, people receiving high doses of steroids, people receiving treatment for cancer with x-rays, drugs or chemotherapy, as well as people who have received blood products or transfusions during the past 5 months.[31]

Side effects

Serious side effects are very rare. From 1998 to 2013, only one vaccine-related death was reported: an English child with pre-existent leukemia. In some occasions, severe reactions have been reported such as meningitis and pneumonia (mainly in inadvertently vaccinated immunocompromised children) as well as anaphylaxis.[15]

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 shot's area.[32]

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.[33]:378 Most of the cases reported have been mild and have not been associated with serious complications.[34]

Generally the vaccine is exceedingly safe: approximately 5% of children who receive the vaccine develop a fever or rash, but as of 1 May 2006, there have been no deaths yet attributable to the vaccine despite more than 40 million doses being administered.[35] Cases of vaccine-related chickenpox have been reported in patients with a weakened immune system,[35][36] but no deaths.

The literature contains several reports of adverse reactions following varicella vaccination, including vaccine-strain zoster in children and adults.[37] A mean of 2,350 reports per year are attributed to varicella vaccine based on 20,004 cases reported to the Vaccine Adverse Event Reporting System (VAERS) database from May 1995 through December 2003. Minor events are known to be under-reported to VAERS.

One study has indicated that anti-VZV vaccine protects against oral and genital herpes outbreaks.[38]

Controversy

A controversy has arisen, in part, because of misunderstandings concerning the role of human embryonic cell lines and vaccine development. Unlike bacteria or fungi, viruses cannot reproduce autonomously and require a living organism host in order to replicate. The ability of the virus to cause infection usually depends on the host with whom its cells have adapted to over generations of replication. In other words, a virus can lead to a more severe infection in certain organisms versus others. To create a vaccine that is safe for individuals while having the ability to induce a protective immune response necessitates choosing an appropriate cell line to grow a virus. WI-38 and MRC-5 are embryonic lung cell lines, derived from two post-mortem fetuses nearly 35 years ago, that have been maintained in laboratory conditions to self-replicate and produce more embryonic lung cells that are used for research purposes. These cell lines cannot develop into a human organism and have no potential for human life. Furthermore, no additional tissue is required from post-mortem fetuses. One of the uses of these cell lines is to provide an environment for virus replication. The Oka/Merck strain of live attenuated varicella virus is one of the viruses that require this environment to grow. [39]Some controversy has arisen due to the mistaken idea that the vaccine contains components of aborted fetus, thus violating the ethics and beliefs of those who oppose the use of aborted fetuses in medical research. In reality, cell line only provides the environment to grow the vaccine and is isolated from cell itself, free from extraneous biological agents.[40] However, other realms of controversy revolve around the use of the WI-38 and MRC-5 cell lines in growing the varicella virus since these human embryonic lung cells were derived from post-mortem fetuses that were aborted. Due to beliefs about the use of human embryonic fetal tissue in medical research, these individuals are opposed to using the varicella vaccine.[39]

See also

References

  1. ^ "WHO Model List of EssentialMedicines". World Health Organization. October 2013. Retrieved 22 April 2014. 
  2. ^ a b "American Academy of Pediatrics. Committee on Infectious Diseases. Varicella vaccine update". Pediatrics 105 (1 Pt 1): 136–41. January 2000.  
  3. ^ "Varicella Vaccine (Chickenpox)". Retrieved May 5, 2010. 
  4. ^ Goldman GS (2005). "Universal varicella vaccination: efficacy trends and effect on herpes zoster". Int J Toxicol 24 (4): 205–213.  
  5. ^ Chaves SS, Gargiullo P, Zhang JX, et al. (March 2007). "Loss of vaccine-induced immunity to varicella over time". N. Engl. J. Med. 356 (11): 1121–9.  
  6. ^ a b The Vaccines and other Biologicals department (May 2003). "Varicella vaccine". WHO. Archived from the original on 2006-08-13. Retrieved 2006-08-18.  — which includes:
    "Varicella vaccines: WHO position paper" (PDF). Weekly Epidemiological Record 73 (32): 241–248. 1998.  
  7. ^ "General questions about the disease". Varicella Disease (Chickenpox). CDCP. December 20, 2001. Retrieved 2006-08-18. 
  8. ^ a b Jack (2005). "Chickenpox Vaccine Linked with Shingles Epidemic". HerpesDoctor. Retrieved 2006-08-18. 
  9. ^ [1]
  10. ^ Tugwell BD, Lee LE, Gillette H, Lorber EM, Hedberg K, Cieslak PR (March 2004). "Chickenpox outbreak in a highly vaccinated school population". Pediatrics 113 (3 Pt 1): 455–9.  
  11. ^ http://www.al.com/news/huntsvilletimes/index.ssf?/base/news/113464189674151.xml&coll=1
  12. ^ "Chicken Pox Outbreak". Retrieved August 2014. 
  13. ^ By HealthiNation. "Yahoo! Health". Health.yahoo.com. Retrieved 2011-02-08. 
  14. ^ Pirofski L, Casadevall A (1 January 1998). "Use of Licensed Vaccines for Active Immunization of the Immunocompromised Host". Clin Microbiol Rev 11 (1): 1–26.  
  15. ^ a b Gershon, A. A. (2013). "Varicella zoster vaccines and their implications for development of HSV vaccines". Virology 435 (1): 29–36.  
  16. ^ a b Harpaz, Rafael. "Prevention of Herpes Zoster: Recommendations of the Advisory Committee on Immunization Practices (ACIP)". Centers for Disease Control. Retrieved 15 June 2014. 
  17. ^ Yih WK, Brooks DR, Lett SM, Jumaan AO, Zhang Z, Clements KM, Seward JF (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: 68–68.  
  18. ^ Brisson M, Gay NJ, Edmunds WJ, Andrews NJ (2002). "Exposure to varicella boosts immunity to Herpes-zoster: implications for mass vaccination against varicella". Vaccine 20 (19–20): 2500–7.  
  19. ^ Leung, Jessica; Rafael Harpaz, Noelle-Angelique Molinari, Aisha Jumaan, and Fangjun Zhou (2011-02-01). "Herpes Zoster Incidence Among Insured Persons in the United States, 1993–2006: Evaluation of Impact of Varicella Vaccination". Clinical Infectious Diseases 52 (3): 332–340.  
  20. ^ Tanuseputro, Peter; Brandon Zagorski; Kevin J. Chan; Jeffrey C. Kwong (2011-11-03). "Population-based incidence of herpes zoster after introduction of a publicly funded varicella vaccination program". Vaccine 29 (47): 8580–8584.  
  21. ^ Carville, Kylie; Michaela A. Riddell; Heath A. Kelly (2010-03-16). "A decline in varicella but an uncertain impact on zoster following varicella vaccination in Victoria, Australia". Vaccine 28 (13): 2532–2538.  
  22. ^ "Varicella (Chickenpox)". Center for Disease Control. Retrieved 16 April 2014. 
  23. ^ a b Lopez, Adriana; Schmid, Scott; Bialek, Stephanie (2011). "Chapter 17: Varicella". In Roush, Sandra W.; McIntyre, Lynne; Baldy, Linda M. Manual for the Surveillance of Vaccine-Preventable Diseases (5th ed.). Atlanta GA: Centers for Disease Control and Prevention. 
  24. ^ Seward JF, Watson BM, Peterson CL, et al. (2002). "Varicella disease after introduction of varicella vaccine in the United States, 1995–2000". JAMA 287 (5): 606–11.  
  25. ^ Nguyen HQ, Jumaan AO, Seward JF (2005). "Decline in mortality due to varicella after implementation of varicella vaccination in the United States" (PDF). N Engl J Med 352 (5): 450–8.  
  26. ^ Patel MS, Gebremariam A, Davis MM (2008). "Herpes zoster-related hospital admissons and expenditures before and after introduction of the varicella vaccine in the United States". Control Hosp. Epidemiol. 29 (12): 1157–1163.  
  27. ^ Yih WK, Brooks DR, Lett SM, Jumaan AO, Zhang Z. Clements KM, Seward JF (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: 68–68.  
  28. ^ Yawn BP, Saddier P, Wollan PC, St Sauver JL, Kurland MJ, Sy LS (2007). "A Population-Based Study of the Incidence and Complication Rates of Herpes Zoster Before Zoster Vaccine Introduction". Mayo Clin Proc. 82 (11): 1341–1349.  
  29. ^ Szabo, Liz (2011-07-25). "Vaccine has nearly eliminated chickenpox deaths in children". USA Today. 
  30. ^ "Who should get this vaccine?". Retrieved May 5, 2010. 
  31. ^ "Who should not receive the varicella vaccine?". Retrieved May 5, 2010. 
  32. ^ "What side effects have been reported with this vaccine?". Retrieved May 5, 2010. 
  33. ^ James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier.  
  34. ^ "Vaccine Information for the public and health professionals". Retrieved May 5, 2010. 
  35. ^ a b Wise RP, Salive ME, Braun MM, et al. (2000). "Postlicensure safety surveillance for varicella vaccine". JAMA 284 (10): 1271–9.  
  36. ^ Quinlivan MA, Gershon AA, Nichols RA, La Russa P, Steinberg SP, Breuer J (2006). "Vaccine Oka Varicella-zoster virus genotypes are monomorphic in single vesicles and polymorphic in respiratory tract secretions". J Infect Dis 193 (7): 927–30.  
  37. ^ For example:
  38. ^ "Efficacy of the anti-VZV (anti-HSV3) vaccine in HSV1 and HSV2 recurrent herpes simplex disease: a prospective study". Retrieved 25 November 2014. 
  39. ^ a b "Human Fetal Links with Some Vaccines". Retrieved 2014-12-08. 
  40. ^ "Varicella Virus Vaccine Live Suspension for subcutaneous injection: Highlights of Prescribing Information". Merck & Co, Inc. December 2013. Retrieved December 2014. 

External links

  • Centers for Disease Control and Prevention (CDC) (March 2012). "FDA approval of an extended period for administering VariZIG for postexposure prophylaxis of varicella".