PCV13 Is Promising Against Worrisome Serotypes
In this study, as in other studies, the incidence of adverse events including injection site tenderness, erythema, and induration were not significantly different between the two groups.
The results from the French study were mirrored in a similar study conducted by Dr. Chaamala Klinger of the University of Oxford (England), and colleagues. This study included data from 135 infants aged 6–14 weeks who were randomized to receive PCV13 and 132 infants who received PCV7. Infants in both groups received the meningococcal serotype C vaccine at 2 and 4 months of age, and the pneumococcal conjugate vaccine, plus a DTaP, IPV, and Hib vaccine at age 2, 3, and 4 months.
Overall, 79%–96% of the children who received PCV13 met the criteria for protection against the six serotypes not included in PCV7, and 95% met the criteria for protection against 19A. “PCV13 was immunogenic and well tolerated when given as part of the UK infant vaccine course,” the researchers wrote.
Local reactions including tenderness, induration, and erythema were similar between the two groups, as were systemic reactions.
A study of the safety and immunogenicity of PCV13 when it was produced on a manufacturing scale supported the results from the three pilot studies.
In this study, conducted by Dr. Janusz Gadzinowski of the Poznan (Poland) University of Medical Sciences, and colleagues, 134 healthy 2-month-olds were randomized to receive the PCV13 pilot vaccine and 135 received the PCV13 manufacturing scale vaccine.
The infants in each group received the PCV13 along with a DTaP, IPV, Hib vaccine, and a hepatitis B vaccine. The infants were vaccinated at 2, 3, and 4 months of age, and the researchers took blood samples at 5 months to test for immune response.
Overall, the proportions of responders who met the criteria for immunogenicity and geometric mean concentration were similar in both groups. For serotype 19A, both groups achieved identical response rates of 99%.
Adverse events were mostly mild or moderate and the investigators considered them unrelated to vaccine. Only one serious adverse event (a case of inconsolable crying) was considered vaccine related, they said. All four studies were supported by Wyeth, a manufacturer of PCV13.
S. pneumoniae Serotype 19A Tied To Necrotizing Pneumonia in Kids
Serotype 19A of Streptococcus pneumoniae is the culprit behind some complicated cases of necrotizing pneumonia in young children, based on findings from four cases that occurred between Sept. 7, 2007, and March 30, 2008, at a single hospital.
“Severe necrotizing pneumonia caused by this serotype had not previously been reported in children,” said Dr. Susan Wootton of the University of Texas, Houston, who presented the cases with her associates in a poster at the jointly held annual meeting of ICAAC and IDSA.
The 19A strain is one of several that are not included in the current pneumococcal conjugate vaccine, PCV7. Data from the Centers for Disease Control and Prevention that also were presented at the meeting showed an increase in invasive pneumococcal disease from nonvaccine serotypes in all age groups.
The patients ranged in age from 3 to 4 years (mean age, 3.4 years). Three were previously healthy and one had asthma. All four had been vaccinated with PCV7. S. pneumoniae was isolated from pleural fluid in three cases and from blood in three cases.
Chest radiographs revealed multilobar infiltrates in four children, empyema in three, and pneumatoceles in two. Three children were admitted to the intensive care unit and intubated 5–22 days. Three children had abscesses that required surgical drainage. The hospital stays ranged from 11 to 28 days.
Serotype 19A has not previously been reported as a cause of complicated pneumonia in children, but these cases suggest that it should now be considered in the differential diagnosis, Dr. Wootton and her associates noted. The results support the need for an expanded pneumococcal vaccine, they said.
Dr. Wootton had no financial conflicts to disclose.
