Updated: March 31, 2010
Streptococcus pneumoniae are a group of bacteria also known as pneumococci. Pneumococci live in the nose and throats of people of all ages. Pneumococci can infect many different sites, some common—like the middle ear and the sinuses—and some less common but more serious, including the lungs (pneumonia), central nervous system (meningitis), and blood stream (bacteremia).
Serious pneumococcal infections are most common in infants, toddlers, smokers, and the elderly. In addition, people with certain health problems (e.g., immune deficiencies, sickle cell disease, lack of a functioning spleen) are at high risk for acquiring invasive pneumococcal disease. Children from African-American and Native American populations also have higher rates of invasive (serious) pneumococcal disease than white children.
A heptavalent pneumococcal conjugate vaccine (PCV7 vaccine), containing the 7 most common pneumococcal serotypes causing invasive infections in children in North America was licensed in the US and recommended for routine use in infants in 2000. The PCV7 vaccine has dramatically reduced the rates of invasive pneumococcal disease, otitis media and nasal carriage of the vaccine serotypes among all age groups, including the immunocompromised and older individuals. The vaccine has also reduced the racial disparities in pneumococcal disease.
PCV7 has proven to be a cost effective vaccine because of the disease it prevents in young children. Vaccinating children against pneumococcus also has provided protection to their family members and the communities where they live, making it a cost saving vaccine when its effects on community immunity are considered.
However, while the PCV7 vaccine has reduced pneumococcal disease caused by the seven most common types causing infection in children, there are other pneumococcal types which can also cause serious infections in children. Surveillance suggests an increase in disease in children aged < 5 years due to these nonvaccine serotypes, especially serotypes 3, 7F, and 19A, some of which are antibiotic resistant. Because children are the reservoir for the serotypes that cause invasive disease in older people, broadening the coverage of serotypes in the vaccine is desirable.
On February 24, 2010, the FDA licensed a 13-valent pneumococcal conjugate vaccine (PCV13). On the same day, the Advisory Committee on Immunization Practices recommended that this vaccine replace the PCV7 vaccine in the infant schedule when it becomes available. PCV13, will protect against the same seven strains that were in PCV7 but also has the potential to further reduce the amount of invasive pneumococcal disease in the United States caused by 6 additional strains, including 3, 7F and 19A.
The pneumococcal vaccine is available as:
Product: Pneumovax 23 (PPS)
Year licensed: 1977
Product: Pnu-Imune 23 (PPS)
Year licensed: 1979
Product: Prevnar (PCV7 - Conjugate)
Year licensed: 2000 to be replaced by PCV13
Product: Prevnar (PCV13 -Conjugate)
Year licensed: 2010 to ultimately replace PCV7
The pneumococcal PPS vaccine used today for older children and adults is “23-valent”— it is effective against 23 types of pneumococci. The 23-valent PPS vaccine protects against 85% to 90% of the types of the pneumococcus that cause invasive infections in these age groups.
Because polysaccharide vaccines are not effective in children younger than two to three years of age, conjugate vaccines were developed. In February 2000, the FDA licensed Prevnar, a “7-valent” conjugate vaccine (PCV7). PCV7 targeted the seven most common types of the pneumococci, which accounted for 80-85% of invasive disease in infants and toddlers. Although the vaccine is generally begun at two months of age, children as young as six weeks of age may receive the conjugate vaccine.
Because a number of other pneumococci are becoming increasingly more common in young children, the new pneumococcal conjugate vaccine (PCV13) containing 6 additional strains was developed to replace PCV7.
Some cases of invasive pneumococcal disease have also been caused by strains not included in PCV 13, but which are included in PPSV23. Therefore, in addition to receiving PCV13, children with underlying medical conditions listed below should receive PPSV23 at age 2 years or as soon as possible after the diagnosis of chronic illness is made.
Who should receive the 23-valent PPS vaccine?
Who should not receive the 23-valent PPS vaccine?
Who should receive the 13-valent conjugate vaccine (PCV13)?
Who should receive the 7-valent conjugate vaccine (PCV7)?
Other children who might benefit from receiving the 7-valent conjugate PCV7 vaccine:
Who should not receive the 7-valent (PCV7) or the 13-valent (PCV13) conjugate vaccines?
This vaccine is recommended by:
The complete childhood and adult immunization schedules can be found at the CDC site.
The 23-valent PPS vaccine is given in one shot. Five years after the first shot, a booster is recommended for some individuals. For infants and children, until PCV13 is available, PCV7 should continue to be used. Once PCV 13 is widely available, it will completely replace PCV7, given as a series of four shots at 2, 4, 6, and 12 through 15 months of age.
Completing the primary series (i.e., the first 3 doses) of PCV7 (and ultimately PCV13) vaccine within the first year of life gives very good protection, but a child is not as fully protected until after the booster dose is given after their first birthday (i.e., 12-15 months of age).
Booster dose(s) extend the period of time over which a child is protected later in life. They are given since the protection received from a primary series given during infancy begins to wear off over time.
If the first dose is delayed, other schedules apply as described by the CDC.
The 23-valent PPS vaccine is not effective in children younger than 2 years of age. It’s effectiveness at preventing disease ranges from 57% to 75%. Protection lasts between three and five years.
A full series of the 7-valent conjugate PCV7 vaccine is 97% effective in preventing invasive pneumococcal disease caused by the seven types of the pneumococci contained in the vaccine. The vaccine is 89% effective in preventing invasive disease caused by all strains of the pneumococci. The vaccine reduces the incidence of ear infection by about 10% and the need for tubes in the middle ears of children by 20%. Since PCV7 immunization of young children began in the US, there has been a decrease in the number of invasive pneumococcal infections due to the strains in the vaccine (but not to strains that are not in the PCV7 vaccine) in all age groups, including among those who are over the age of 65 years.
PCV13 should be as effective for the original PCV7 serotypes of pneumococci and will be more effective than PCV7 for prevention of invasive pneumococcal infections because it will provide protection against an additional 6 serotypes.
The 23-valent PPS vaccine:
About half of those immunized with the 23-valent PS vaccine will experience no reactions. Approximately 50% of those vaccinated experience mild reactions, such as soreness and redness where the shot was given. Less than 1% report fever, chills, and a general sense of being ill that lasts for one to two days.
In very rare cases (far less than 1 out of 10,000) serious allergic reactions occur. These may include trouble breathing, hives, becoming pale or weak, having a very fast heartbeat, or feeling dizzy.
The 7-valent PCV7 and 13-valent PCV13 conjugate vaccines:
Those vaccinated with the PCV7 or PCV13 vaccines may have mild reactions that include soreness or redness where the shot was given, irritability, drowsiness, and decreased appetite. Twenty-one percent get a fever over 100.3 degrees F.
Seizures have been reported after the use of the 7-valent conjugate vaccine in less than 1 in 10,000 immunized. Almost all seizures occurred less than four days after receiving the vaccine. Over half of the children had experienced previous seizures (55%) or had a fever at the time of the seizure (68%).
Until recently, pneumococcal infections could be treated effectively with certain antibiotics. However, more and more of these infections are becoming antibiotic-resistant. For this reason, it is especially important to prevent pneumococcal infections with vaccines.