Pneumococcal conjugate vaccine: Difference between revisions
No edit summary |
|||
| Line 89: | Line 89: | ||
=======================({{No More Links}})=============================--> |
=======================({{No More Links}})=============================--> |
||
* {{dmoz|Health/Pharmacy/Drugs_and_Medications/P/Pneumococcal_Vaccine}} |
* {{dmoz|Health/Pharmacy/Drugs_and_Medications/P/Pneumococcal_Vaccine}} |
||
*[http://www.preventpneumo.org Pneumococcal Accelerated Development and Introduction Plan] |
|||
* [http://www.wyeth.com/ Wyeth.com] — Official [[Wyeth]] website |
* [http://www.wyeth.com/ Wyeth.com] — Official [[Wyeth]] website |
||
*[http://www.gsk.com/media/pressreleases/2009/2009_pressrelease_10039.htm Synflorix at GSK] |
*[http://www.gsk.com/media/pressreleases/2009/2009_pressrelease_10039.htm Synflorix at GSK] |
||
Revision as of 20:20, 9 April 2009
| Vaccine description | |
|---|---|
| Target | Streptococcus pneumoniae |
| Vaccine type | Conjugate |
| Clinical data | |
| ATC code | |
Pneumococcal conjugate vaccine (PCV) is a vaccine used to protect infants and young children against disease caused by the bacterium Streptococcus pneumoniae (pneumococcus). There are currently two PCV vaccines available on the global market: Prevnar (sometimes called Prevenar) and Synflorix. Prevnar is a heptavalent vaccine, meaning that it contains the cell membrane sugars of seven serotypes of pneumococcus, conjugated with Diphtheria proteins. It is manufactured by Wyeth as the brand name Prevnar.[1] In the United States, vaccination with Prevnar is recommended for all children younger than 2 years, and for unvaccinated children between 24 and 59 months old who are at high risk for pneumococcal infections.[2] Synflorix received a positive opinion from the European Medicines Agency for use in the European Union in January 2009 [3]. Synflorix is produced by GlaxoSmithKline. Synflorix is a ten valent vaccine meaning that it contains ten serotypes of pneumococcus (1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, and 23F) which are conjugated to a carrier protein. GSK expects that Synflorix will receive full marketing authorization in the next few months [4].
Production technique
Prevnar
Prevnar is produced from the seven most prevalent strains of Streptococcus pneumoniae bacteria in the US. The bacterial capsule sugars, a characteristic of these pathogens, are linked to CRM197, a nontoxic recombinant variant of diphtheria toxin (Corynebacterium diphtheriae).
The vaccine's polysaccharide sugars are grown separately in soy peptone broths. Through reductive amination, the sugars are directly conjugated to the protein carrier CRM197 to form the glycoconjugate. CRM197 is grown in Corynebacterium diphtheriae strain C7 in a medium of casamino acids and yeast extracts.[1]
The current 7-valent formulation contains serotypes 4,6B,9V,14,18C,19F, and 23F, and results in a 98% probability of protection against these strains, which caused 80% of the pneumococcal disease in infants in the US. In 2009, Wyeth will be introducing Prevnar 13 which will contain six additional strains (i.e., 1, 3, 5, 6A, 19A and 7F), which will protect against the majority of the remaining pneumococcal infections.
Synflorix
Synflorix contains the seven pneumococcal serotypes that are contained in Prevnar. In addition, Synflorix protects against serotypes 1, 5, and 7F. Eight of the ten serotypes are linked to a protein carrier derived from non typeable Haemophilus influenzae.
Centers for Disease Control recommendation
In 2001, the Centers for Disease Control (CDC), upon advice from its Advisory Committee on Immunization Practices, recommended the vaccine be administered to every infant and young child in the US. The resulting demand outstripped production, creating shortages not resolved until 2004. All children, according to current US vaccination schedules, should receive four doses, at two, four, six, and again between twelve and fifteen months of age.
Efficacy
Prevnar is designed to stop seven of about ninety bacteria which cause invasive pneumococcal disease. Each year, IPD kills approximately one million children worldwide.[2]
Since approval, Prevnar's efficacy in preventing invasive pneumococcal disease has been documented by a number of epidemiologic studies.[5][6][7]
The vaccine is however, primarily developed for the U.S. and European epidemiological situation, and therefore it has only a limited coverage of serotypes causing serious pneumococcal infections in most developing countries.[8]
Evidence supporting addition to routine vaccination schedules
After introduction of the pneumococcal conjugate vaccine in 2000, several studies described a decrease in invasive pneumococcal disease in the United States. One year after its introduction, a group of investigators found a 69% drop in the rate of invasive disease in those age less than 2 years of age.[5] By 2004, all-cause pneumonia admission rates had declined by 39% (95% CI 22–52) and rates of hospitalizations for pneumococcal meningitis decreased by 66% (95% CI 56.3-73.5) in children younger than 2.[9][10]
Interestingly, rates of invasive pneumococcal disease among adults has also declined since the introduction of the vaccine.[5][10] Although, it is more difficult to specifically attribute this decline in adults to the childhood pneumococcal conjugate vaccine since the adult pneumococcal 23-valent polysaccharide vaccine is also available.
While an overall decline in invasive pneumococcal disease is well documented, concerns have been raised regarding a potential increase in the rate of infections caused by serotypes not covered in the vaccine. Recent data suggest that serotype replacement is increasing (1.61- and 1.28-fold increase in children and adults) but remains minimal when compared to the significant reduction observed in the burden of this vaccine-preventable disease.[11]
Clinical study
Prevnar was administered to nearly 20,000 children prior to licensure, and the side effects were evaluated. Rashes at the site of injection were noted in about one percent of children.
Vaccination in the Developing World
Pneumococcal disease is the leading vaccine-preventable killer of young children worldwide, according to the World Health Organization (WHO), killing over 800,000 and up to a million children a year. Ninety percent of these deaths occur in the developing world.[12] Historically 15-20 years pass before a new vaccine reaches one quarter of the population of the developing world.[13] Pneumococcal vaccines Accelerated Development and Introduction Plan (PneumoADIP) is a GAVI Alliance (GAVI) funded project to accelerate the introduction of pneumococcal vaccinations into the developing world through partnerships between countries, donors, academia, international organizations and industry. With action now, a projected 5.4 million child deaths can be prevented by 2030. In May 2007, 30 of the 72 GAVI countries expressed interest in introducing pneumococcal conjugate vaccine between 2008 and 2010. These countries are Benin, Burundi, the Republic of Congo, Rep. of Cote d'Ivoire, Djibouti, the Democratic Republic of Congo, Ethiopia, Ghana, Guyana, Honduras, Indonesia, Kenya, Madagascar, Malawi, Mali, Mongolia, Nicaragua, Pakistan, Rwanda, Sao Tome and Principe, Senegal, Solomon Islands, Sri Lanka, Sudan, The Gambia, Timor Leste, Togo, Uganda, Yemen, and Zambia.[14]
Sales
Prevnar is among Wyeth's top revenue producers, with sales in 2005 of $1.5 billion, up 43 percent from 2004.Wyeth Annual report
Controversy
Controversy has arisen regarding pneumococcal vaccine advertisements aired by Wyeth in Poland and Saudi Arabia. A television commercial for Prevnar, showing a dying child and its mother, was banned in Poland by the main pharmaceutical inspector (GIF), Zofia Ulz, on April 3, 2007. According to Ulz, the ad was designed to provoke fear to attract customers. Wyeth responded by asserting the tactic was used to increase awareness of the potential danger represented by pneumococcal infections.[15]
In addition, Wyeth has been accused of conflict of interest in economic evaluations of Prevnar.[16]
The selling price of conjugate vaccines is clearly very high.[8][17] The WHO, pneumo ADIP and other associations are taking steps to make cheaper, more effective vaccines available with partners in countries such as India, and Brazil.[citation needed]
References
- ^ "Pneumococcal 7-valent Conjugate Vaccine (Diphtheria CRM197 Protein)". Wyeth. 2006.
- ^ "American Academy of Pediatrics. Committee on Infectious Diseases. Policy statement: recommendations for the prevention of pneumococcal infections, including the use of pneumococcal conjugate vaccine (Prevnar), pneumococcal polysaccharide vaccine, and antibiotic prophylaxis". Pediatrics. 106 (2 Pt 1): 362–6. 2000. PMID 10920169.
- ^ EMEA Document
- ^ [http://www.gsk.com/media/pressreleases/2009/2009_pressrelease_10012.htm GSK Release}
- ^ a b c Whitney CG, Farley MM, Hadler J; et al. (2003). "Decline in invasive pneumococcal disease after the introduction of protein-polysaccharide conjugate vaccine". The New England journal of medicine. 348 (18): 1737–46. doi:10.1056/NEJMoa022823. PMID 12724479.
{{cite journal}}: Explicit use of et al. in:|author=(help); Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Poehling KA, Talbot TR, Griffin MR; et al. (2006). "Invasive pneumococcal disease among infants before and after introduction of pneumococcal conjugate vaccine". JAMA : the journal of the American Medical Association. 295 (14): 1668–74. doi:10.1001/jama.295.14.1668. PMID 16609088.
{{cite journal}}: Explicit use of et al. in:|author=(help); Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Whitney CG, Pilishvili T, Farley MM; et al. (2006). "Effectiveness of seven-valent pneumococcal conjugate vaccine against invasive pneumococcal disease: a matched case-control study". Lancet. 368 (9546): 1495–502. doi:10.1016/S0140-6736(06)69637-2. PMID 17071283.
{{cite journal}}: Explicit use of et al. in:|author=(help); Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b Barocchi MA, Censini S, Rappuoli R (2007). "Vaccines in the era of genomics: the pneumococcal challenge". Vaccine. 25 (16): 2963–73. doi:10.1016/j.vaccine.2007.01.065. PMID 17324490.
{{cite journal}}: CS1 maint: multiple names: authors list (link) Cite error: The named reference "pmid17324490" was defined multiple times with different content (see the help page). - ^ Grijalva CG, Nuorti JP, Arbogast PG, Martin SW, Edwards KM, Griffin MR (2007). "Decline in pneumonia admissions after routine childhood immunisation with pneumococcal conjugate vaccine in the USA: a time-series analysis". Lancet. 369 (9568): 1179–86. doi:10.1016/S0140-6736(07)60564-9. PMID 17416262.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b Tsai CJ, Griffin MR, Nuorti JP, Grijalva CG (2008). "Changing epidemiology of pneumococcal meningitis after the introduction of pneumococcal conjugate vaccine in the United States". Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 46 (11): 1664–72. doi:10.1086/587897. PMID 18433334.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Albrich WC, Baughman W, Schmotzer B, Farley MM (2007). "Changing characteristics of invasive pneumococcal disease in Metropolitan Atlanta, Georgia, after introduction of a 7-valent pneumococcal conjugate vaccine". Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 44 (12): 1569–76. doi:10.1086/518149. PMID 17516400.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ "Pneumococcal vaccines. WHO position paper". Relevé épidémiologique hebdomadaire / Section d'hygiène du Secrétariat de la Société des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 74 (23): 177–83. 1999. PMID 10437429.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ PneumoADIP | Need for PneumoADIP
- ^ PneumoADIP | Vaccine Introduction
- ^ "Controversial pneumococcal vaccine ad - Polish Market News". Retrieved 2008-02-20.
- ^ Beutels P (2004). "Potential conflicts of interest in vaccine economics research: a commentary with a case study of pneumococcal conjugate vaccination". Vaccine. 22 (25–26): 3312–22. doi:10.1016/j.vaccine.2004.03.001. PMID 15308354.
- ^ Beall B (2007). "Vaccination with the pneumococcal 7-valent conjugate: a successful experiment but the species is adapting". Expert review of vaccines. 6 (3): 297–300. doi:10.1586/14760584.6.3.297. PMID 17542743.
{{cite journal}}: Unknown parameter|month=ignored (help)