Pneumococcal vaccines are
vaccine
A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifie ...
s against the bacterium ''
Streptococcus pneumoniae
''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They are ...
''.
[ Their use can prevent some cases of ]pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
, meningitis
Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...
, and sepsis
Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...
.[ There are two types of pneumococcal vaccines: ]conjugate vaccine
A conjugate vaccine is a type of subunit vaccine which combines a weak antigen with a strong antigen as a carrier so that the immune system has a stronger response to the weak antigen.
Vaccines are used to prevent diseases by invoking an immune ...
s and polysaccharide vaccines.[ They are given by injection either into a muscle or just under the skin.][
The ]World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
(WHO) recommends the use of the conjugate vaccine in the routine immunizations given to children.[ This includes those with ]HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
.[ The recommended three or four doses are between 71 and 93% effective at preventing severe pneumococcal disease.][ The polysaccharide vaccines, while effective in healthy adults, are not effective in children less than two years old or those with poor immune function.][
These vaccines are generally safe.][ With the conjugate vaccine about 10% of babies develop redness at the site of injection, fever, or change in sleep.][ Severe allergies are very rare.][
Whole cell vaccinations were developed alongside characterisation of the subtypes of pneumococcus from the early 1900s.
The first pneumococcal vaccine was developed in the 1980s.][; ] It is on the World Health Organization's List of Essential Medicines
The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health ...
.
Recommendations
Worldwide
Pneumococcal vaccines Accelerated Development and Introduction Plan (PneumoADIP) is a program to accelerate the evaluation and access to new pneumococcal vaccines in the developing world. PneumoADIP is funded by the Global Alliance for Vaccines and Immunization (GAVI). Thirty GAVI countries have expressed interest in participating by 2010. PneumoADIP aims to save 5.4 million children by 2030.
A pilot Advance Market Commitment
An advance market commitment (AMC) is a binding contract, typically offered by a government or other financial entity, used to guarantee a viable market for a product once it is successfully developed. Generally AMCs are used in circumstances wher ...
(AMC) to develop a vaccine against pneumococcus was launched by GAVI in June 2009 as a strategy to address two of the major policy challenges to vaccine introduction: a lack of affordable vaccines on the market, and insufficient commercial incentives to develop vaccines for diseases concentrated in developing countries. Under the terms of an AMC, donors make a legally binding guarantee that, if a future vaccine is developed against a particular disease, they will purchase a predetermined amount at an agreed-upon price. The guarantee is linked to safety and efficacy standards that the vaccine must meet and is structured in a way to allow several firms to compete to develop and produce the best possible new product. AMCs reduce risk to donor governments by eliminating the need to fund individual research and development projects that may never produce a vaccine. If no company produces a vaccine that meets the predetermined standards, governments (and thus their taxpayers) spend nothing. For the bio-pharmaceutical industry, AMCs create a guaranteed market, with a promise of returns that would not normally exist. For developing countries
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
, AMCs provide funding to ensure that those vaccines will be affordable once they have been developed. It is estimated that the pneumococcal AMC could prevent more than 1.5 million childhood deaths by 2020.
Doctors Without Borders
Doctor or The Doctor may refer to:
Personal titles
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** Physician
** Surgeon
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** ...
has criticized GAVI's pneumococcal AMC for not encouraging innovation, discouraging competition from new market entrants, and raising vaccine costs. They said that it had allowed Pfizer
Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfizer ...
and GlaxoSmithKline
GSK plc, formerly GlaxoSmithKline plc, is a British multinational pharmaceutical and biotechnology company with global headquarters in London, England. Established in 2000 by a merger of Glaxo Wellcome and SmithKline Beecham. GSK is the ten ...
to maintain a duopoly, while making it more difficult for the Serum Institute of India
Serum Institute of India (SII) is an Indian biotechnology and biopharmaceuticals company, based in Pune. It is the world's largest manufacturer of vaccines. It was founded by Cyrus Poonawalla in 1966 and is a part of Cyrus Poonawalla Group.
...
to sell their cheaper vaccine. The duopoly allowed price discrimination
Price discrimination is a microeconomic pricing strategy where identical or largely similar goods or services are sold at different prices by the same provider in different markets. Price discrimination is distinguished from product different ...
; somewhat higher prices for GAVI, and unaffordable prices (about ten time the GAVI price) for middle-income countries too rich for GAVI aid. The pneumococcal program (unlike previous market-shaping programs from GAVI) did not include any mechanism for increasing competition.
The Humanitarian Mechanism makes the pneumococcal vaccine available to humanitarian actors (but not governments) at a lower than normal price during humanitarian emergencies.
Belgium
The national vaccination program started vaccinating newborns in 2004 with the 7-valent pneumococcal conjugate vaccine (PCV 7). This was changed into the 13-valent conjugate (PCV 13) in 2011. The switch to the 10-valent conjugate (PCV 10) was made in July 2015 in Flanders
Flanders (, ; Dutch: ''Vlaanderen'' ) is the Flemish-speaking northern portion of Belgium and one of the communities, regions and language areas of Belgium. However, there are several overlapping definitions, including ones related to culture, ...
and May 2016 in Wallonia
Wallonia (; french: Wallonie ), or ; nl, Wallonië ; wa, Waloneye or officially the Walloon Region (french: link=no, Région wallonne),; nl, link=no, Waals gewest; wa, link=no, Redjon walone is one of the three regions of Belgium—alo ...
. In late 2020 a start was made with the vaccination of care home residents with the 23-valant pneumococcal polysaccharide vaccine (PPV 23).
Canada
Health Canada
Health Canada (HC; french: Santé Canada, SC)Health Canada is the applied title under the Federal Identity Program; the legal title is Department of Health (). is the Structure of the Canadian federal government#Departments, with subsidiary unit ...
's general recommendations are 13-valent pneumococcal conjugate vaccine (PCV 13) vaccine for children aged 2 months to 18 years and 23-valent pneumococcal polysaccharide vaccine (PPV 23) vaccine for adults.
India
In May 2017, the Government of India decided to include pneumococcal conjugate vaccine in its Universal Immunization Programme Universal Immunisation Programme (UIP) is a vaccination programme launched by the Government of India in 1985. It became a part of Child Survival and Safe Motherhood Programme in 1992 and is currently one of the key areas under National Rural Health ...
.
The Netherlands
The national vaccination program started including the pneumococcal vaccine for newborns in April 2006.
The Health Council advised in 2018 that those who are over the age of 60 should also be vaccinated on a 5-year recurring schedule. The resulting program from this, NPPV, started at the end of 2020.
Health authorities reported in December 2020 that former COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...
patients also have an indication for this vaccine because of the damage their lungs incurred. Vaccinating this group is not part of the NPPV program.
South Africa
The 7- and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13) were introduced into the national Expanded Program on Immunization (EPI) in South Africa in 2009 and 2011, respectively. South Africa became the first African country – and the first nation in the world with a high HIV prevalence – to introduce PCV7 into its routine immunization program. Rates of invasive pneumococcal disease (IPD) – including cases caused by antibiotic-resistant bacteria – have fallen substantially in South Africa following the introduction of PCV7. Among children under two years of age, the overall incidence of IPD declined nearly 70% after PCV introduction, and rates of IPD caused by bacteria specifically targeted by the vaccine decreased nearly 90%. Due to the indirect protection conferred by herd immunity
Herd immunity (also called herd effect, community immunity, population immunity, or mass immunity) is a form of indirect protection that applies only to contagious diseases. It occurs when a sufficient percentage of a population has become imm ...
, a significant decline in IPD in children and in unvaccinated adults has also been shown.
Pneumovax 23 is used for all ages and, according to the enclosed patient information leaflet, has a reported 76% to 92% protective efficacy (pneumococcal types 1, 2, 3, 4, 5, 6B**, 7F, 8, 9N, 9V**, 10A, 11A, 12F, 14**, 15B, 17F, 18C, 19A**, 19F**, 20, 22F, 23F** and 33F** are included, where ** indicates drug-resistant pneumococcal infections; these are the 23 most prevalent or invasive pneumococcal types of ''Streptococcus pneumoniae'').
United Kingdom
It was announced in February 2006, that the UK government would introduce vaccination with the conjugate vaccine in children aged 2, 4 and 13 months. This included changes to the immunisation programme in general. In 2009, the European Medicines Agency approved the use of a 10 valent pneumococcal conjugate vaccine for use in Europe. The 13-valent pneumococcal vaccine was introduced in the routine immunization schedule of the UK in April 2010.
United States
In the United States, a heptavalent pneumococcal conjugate vaccine
Pneumococcal conjugate vaccine is a pneumococcal vaccine and a conjugate vaccine used to protect infants, young children, and adults against disease caused by the bacterium ''Streptococcus pneumoniae'' (pneumococcus). It contains purified capsul ...
(PCV 7) (e.g. Prevnar, called Prevenar in some countries) was recommended for all children aged 2–23 months and for at-risk children aged 24–59 months in 2000. The normal four-dose series is given at 2, 4, 6 and 12–14 months of age. In February 2010, a pneumococcal conjugate vaccine which protects against an additional six serotypes was introduced (PCV 13/brand name: Prevnar 13) and can be given instead of the original Prevnar. On 10 June 2021, a pneumococcal conjugate vaccine which protects against 20 serotypes was approved with the brand name Prevnar 20.
Pneumococcal polysaccharide vaccine
Pneumococcal polysaccharide vaccine (PPSV)—known as Pneumovax 23 (PPV-23)—is the first pneumococcal vaccine derived from a capsular polysaccharide.
The polysaccharide antigens were used to induce type-specific antibodies that enhanced op ...
(PPV, Pneumovax is one brand) gives at least 85% protection in those under 55 years of age for five years or longer. Immunization is suggested for those at highest risk of infection, including those 65 years or older. Generally the vaccine should be a single lifetime dose, as there is a high risk of side effects if repeated. The standard 23-valent vaccines are ineffective for children under two years old.
The current guidelines of the American College of Physicians
The American College of Physicians (ACP) is a national organization of internists, who specialize in the diagnosis, treatment, and care of adults.Sokanu "What is an Internist?" Retrieved October 20, 2014 With 161,000 members, ACP is the largest ...
call for the administration of the immunization between ages two and 65 when indicated, or at age 65. If someone received the immunization before age 60, the guidelines call for one-time revaccination. A majority of pharmacists indicate that they recommend all adults 65 and older receive a pneumococcal vaccination.
Revaccination at periodic intervals is also indicated for those with other conditions such as asplenia
Asplenia refers to the absence of normal spleen function and is associated with some serious infection risks. Hyposplenism is used to describe reduced ('hypo-') splenic functioning, but not as severely affected as with asplenism.
''Functional'' a ...
or nephrotic syndrome
Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes protein in the urine, low blood albumin levels, high blood lipids, and significant swelling. Other symptoms may include weight gain, feeling tired, and foamy ...
.
Mechanism
Polysaccharide vaccine
The pneumococcal polysaccharide vaccine
Pneumococcal polysaccharide vaccine (PPSV)—known as Pneumovax 23 (PPV-23)—is the first pneumococcal vaccine derived from a capsular polysaccharide.
The polysaccharide antigens were used to induce type-specific antibodies that enhanced op ...
most commonly used today consists of purified polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
s from 23 serotype
A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or cells are classified together based on their surface antigens, allowing the epi ...
s (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 which release IgM without the assistance of T cells.
This immune response is less robust than the response provoked by conjugated vaccines, which has several consequences. The vaccine is ineffective in children less than 2 years old, presumably due to their less mature immune systems. Non-response is also common amongst older adults. Immunity is not lifelong, so individuals must be re-vaccinated at age 65 if their initial vaccination was given at age 60 or younger. Since no mucosal immunity is provoked, the vaccine does not affect carrier rates, promote herd immunity, or protect against upper or lower respiratory tract infections. Finally, provoking immune responses using unconjugated polysaccharides from the capsules of other bacteria, such as H. influenzae, has proven significantly more difficult.
Conjugated vaccine
The pneumococcal conjugate vaccine
Pneumococcal conjugate vaccine is a pneumococcal vaccine and a conjugate vaccine used to protect infants, young children, and adults against disease caused by the bacterium ''Streptococcus pneumoniae'' (pneumococcus). It contains purified capsul ...
consists of capsular polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
s covalently bound to the diphtheria toxoid CRM197, which is highly immunogenic but non-toxic. This combination provokes a significantly more robust immune response by recruiting CRM197-specific type 2 helper T cells, which allow for immunoglobulin type switching (to produce non-IgM immunoglobulin) and production of memory B cells. Among other things, this results in mucosal immunity and the eventual establishment of lifelong immunity after several exposures. The main drawbacks to conjugated vaccines are that they only provide protection against a subset of the serotypes covered by the polysaccharide vaccines.
depitte, J.; Gove, Sandy; Breiman, Robert F.
Research
Due to the geographic distribution of pneumococcal serotypes, additional research is needed to find the most efficacious vaccine for developing-world populations. In a previous study, the most common pneumococcal serotypes or groups from developed countries were found to be, 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. In order to further pneumococcal vaccine research and reduce childhood mortality, five countries and the Bill & Melinda Gates Foundation established a pilot Advance Market Commitment for pneumococcal vaccines worth US$1.5 billion. Advance Market Commitments are a new approach to public health funding designed to stimulate the development and manufacture of vaccines for developing countries.
There is currently research into producing vaccines than can be given into the nose rather than by injection. It is believed that this improves vaccine efficacy and also avoids the need for injection.
The development of serotype-specific anticapsular monoclonal antibodies has also been researched in recent years. These antibodies have been shown to prolong survival in a mouse model of pneumococcal infection characterized by a reduction in bacterial loads and a suppression of the host inflammatory response. Additional pneumococcal vaccine research is taking place to find a vaccine that offers broad protection against pneumococcal disease.
, pneumonia vaccines target up to 23 forms of the bacterium that cause pneumonia with a new version under development covering 72 strains of the bacterium.[; ]
References
Further reading
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Vaccines
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