Pneumococcal vaccine is a vaccine against bacteria Streptococcus pneumoniae . Its use may prevent some cases of pneumonia, meningitis, and sepsis. There are two types of pneumococcal vaccine: conjugate vaccine and polysaccharide vaccine. They are administered either by injection to the muscle or just under the skin.
The World Health Organization recommends the use of conjugate vaccines in routine immunization given to children. This includes people with HIV/AIDS. Three or four recommended doses are between 71 and 93% effective to prevent severe pneumococcal disease. Polysaccharide vaccines, although effective in healthy adults, are ineffective in children younger than two years or those with poor immune function.
These vaccines are generally safe. With conjugate vaccine about 10% of babies experience redness at the injection site, fever, or changes in sleep. Severe allergies are very rare.
The first pneumococcal vaccine was developed in the 1980s. They are on the World Health Organization's Essential Drug List, the most effective and safe medicines needed in the health system. Wholesale costs in developing countries are around US $ 17 per dose in 2014. In the United States the price is between US $ 25 and US $ 100.
Video Pneumococcal vaccine
Recommendations
Worldwide
Accelerated Developmental Pneumococcal Vaccine and Preliminary Plan (PneumoADIP) is a program to accelerate evaluation and access to new pneumococcal vaccines in developing countries. PneumoADIP is funded by the Global Alliance for Vaccines and Immunizations (GAVI). Thirty GAVI countries have expressed interest in participating in 2010. PneumoADIP aims to save 5.4 million children by 2030.
The Advance Market Commitment (AMC) pilot for developing a vaccine against pneumococcal was launched in June 2009 as a strategy to address two key policy challenges for vaccine introduction: lack of affordable vaccines in the market, and inadequate commercial incentives to develop vaccines for disease concentrations in the country developing. Under the terms of the AMC, donors make a legally binding guarantee that, if future vaccines are developed against certain diseases, they will purchase a predetermined amount at an agreed price. This assurance is related to the safety and efficacy standards that vaccines must meet and are structured in such a way as to enable several companies to compete to develop and produce the best new products. AMC reduces the risk to donor governments by eliminating the need to fund individual research and development projects that may never produce vaccines. If no company produces a vaccine that meets the prescribed standards, the government (and thus their taxpayer) does not issue anything. For the bio-pharmaceutical industry, AMC creates a guaranteed market, with a promise of returns that normally do not exist. For developing countries, AMC provides funding to ensure that the vaccine will be affordable once they are developed. It is estimated that AMC pneumococcal can prevent more than 1.5 million child deaths by 2020.
India
In May 2017, the Government of India decided to include pneumococcal conjugate vaccine at the Universal Immunization Program.
AS
In the United States, the heptavalent pneumococcal conjugate vaccine (PCV 7) (eg Prevnar, called Prevenar in some countries) is recommended for all children 2-23 months and for at-risk children aged 24-59 months in 2000. Normal four -dose given at age 2, 4, 6 and 12-14 months. In February 2010, a pneumococcal congugate vaccine that protects against an additional six serotypes was introduced (PCV 13/brand name: Prevnar 13) and can be given in place of the original Prevnar.
Pneumococcal polysaccharide vaccine (Pneumovax is one brand) provides at least 85% protection for those under 55 for five years or longer. Immunization is recommended for those at high risk of infection, including those 65 years of age or older; generally the vaccine should be a single lifetime dose, because there is a high risk of side effects if repeated. The standard 23-valent vaccine is not effective for children under two years old.
Current guidelines from the American College of Physicians call for immunization administration between the ages of 2 and 65 when indicated, or at age 65. If a person receives immunization before age 60, the guidelines call for one-time re-vaccination.
Re-vaccination at periodic intervals is also indicated for those with other conditions such as asplenia or nephrotic syndrome.
English
It was announced in February 2006 that the British government will introduce vaccinations with conjugate vaccines in children aged 2, 4 and 13 months. This includes changes to the general immunization program. In 2009, the European Medicines Agency approved the use of valentine valveine valum vaccine 10 for use in Europe. 13 valence pneumococcal vaccines were introduced in the UK routine immunization schedule in April 2010.
South Africa
The 7 and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13) were introduced into the National Immunization Expansion Program (EPI) in South Africa in 2009 and 2011, respectively. South Africa became the first African country - and the first country in the world with high HIV prevalence - to introduce PCV7 into its routine immunization program. Levels of invasive pneumococcal disease - including cases caused by antibiotic-resistant bacteria - have declined substantially in South Africa after the introduction of PCV7. Among children under the age of two, the overall incidence of IPD decreased almost 70% after the introduction of PCV, and the level of IPD caused by bacteria specifically targeted by the vaccine decreased by almost 90%. Because of the indirect protection provided by group immunity, significant reductions in IPD in children and in unvaccinated adults have also been demonstrated. Pneumovax 23 is used for all ages and, according to the attached patient information leaflet, has a protective efficacy of 76% to 92% reported (pneumococcal type 1, 2, 3, 4, 5, 6B **, 7F, 8, 9N, 9V ** , 10A, 11A, 12F, 14 **, 15B, 17F, 18C, 19A **, 19F **, 20, 22F, 23F ** and 33F ** including, where ** denotes drug-resistant pneumococcal infections These are the 23 most common or invasive pneumococcal types of Streptococcus pneumoniae ).
Maps Pneumococcal vaccine
Adverse reactions
Conjugate vaccine
Local reactions such as pain, swelling or redness occur in up to 50% of those vaccinated with PCV13, of this amount, 8% are considered severe. The local reaction is more likely after the 4th dose than the previous dose. In clinical trials, fever over 100.4 F (38 C) is reported at a rate of 24-35% after any dose in the primary series and nonspecific symptoms such as decreased appetite or irritability occur in up to 80% of recipients. In a study of vaccine safety data, febrile seizures occur in about 1 in 83,000 to 1 in 6,000 children given PCV 13, and 1 in 21,000 to 1 in 2,000 people given PCV13 and trivalent influenza vaccine at the same time.
Mechanism
Polysaccharide vaccine
The most commonly used polysaccharide vaccine today consists of pure polysaccharides of 23 serotypes (1, 2, 3, 4, 5, 6b, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F). Immunity is induced primarily through stimulation of B cells that release IgM without the help of T cells.
This immune response is less powerful than the response triggered by the conjugate vaccine, which has several consequences. Vaccines are not effective in children younger than 2 years, probably because of their immature immune system. Non-response is also common among older adults. Immunity is not lifelong, so individuals should be revaccinated at age 65 if early vaccination is given at age 60 or younger. Since no mucosal immunity is provoked, the vaccine does not affect the career level, encourages group immunity, or protects against upper or lower respiratory tract infections. Finally, provoking an immune response using unconjugated polysaccharides from other bacterial capsules, such as H. influenzae, has proved much more difficult.
Conjugate vaccine
The conjugate vaccine consists of a covalent capsular polysaccharide bound to a diphtheria CRM197 toxide, which is highly immunogenic but non-toxic. This combination provokes a much stronger immune response by recruiting a special type 2 helper T-cell CRM197, which allows to switch immunoglobulin types (to produce non-IgM immunoglobulins) and production of B memory cells. Among other things, it produces mucosal immunity and ultimately lifelong immune formation after multiple exposures. The main disadvantage for conjugate vaccines is that they only provide protection against a subset of serotypes covered by polysaccharide vaccines.
Research
Due to the geographic distribution of pneumonia serotypes, additional research is needed to find the most potent vaccine for the developing world population. In the previous study, the most common serotype or pneumococcal group of developed countries was found, in descending order, 14, 6, 19, 18, 9, 23, 7, 4, 1 and 15. In developing countries the order was 6, 14, 8, 5, 1, 19, 9, 23, 18, 15 and 7. To further study pneumococcal vaccine and reduce child mortality, five countries and Bill & amp; The Melinda Gates Foundation founded the Pilot Advance Market Commitment for the $ 1.5 billion pneumococcal vaccine. Advance Market Commitments is a new approach to public health funding designed to stimulate the development and manufacture of vaccines for developing countries.
There is currently research to produce vaccines than can be administered to the nose rather than by injection. It is believed that this increases the efficacy of the vaccine and also avoids the need for injections.
The development of monoclonal anticapsular-serotype-specific antibodies has also been studied in recent years. These antibodies have been shown to prolong survival in pneumococcal infection mouse models characterized by decreased bacterial load and suppression of host inflammatory responses. Additional pneumococcal vaccine research is under way to find vaccines that offer widespread protection against pneumococcal disease.
References
External links
- The World Health Organization: Streptococcus pneumoniae
- Advance Market Commitment
- Pneumococcal resource source PATH resource library
- Centers for Disease Control and Prevention (2012). "Ch 16: Inflammatory Lung Disease". At Atkinson W, Wolfe S, Hamborsky J. Epidemiology and Prevention of Vaccine-Preventable Diseases (12th ed.). Washington, D.C.: Public Health Foundation. pp.Ã, 233-248. Archived from the original in 2017-03-10.
Source of the article : Wikipedia
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