Prevnar Vaccine Is Causing Superbug Ear Infections
A vaccine that has dramatically curbed pneumonia and other serious illnesses in children is having an unfortunate effect: promoting new superbugs that cause ear infections.
On Monday, doctors reported discovering the first such germ that is resistant to all drugs approved to treat childhood ear infections. Nine toddlers in Rochester, N.Y., have had the germ and researchers say it may be turning up elsewhere, too.
Flourishing strains
Prevnar prevents seven strains responsible for most cases of pneumonia, meningitis and deadly bloodstream infections. But dozens more strep strains exist, and some have flourished and become impervious to antibiotics since the vaccine combats the more common strains.
If the new strains continue to spread, “it tells us the vaccine is becoming less effective” and needs to be revised, said Dr. Dennis Maki, infectious diseases chief at the University of Wisconsin-Madison Hospitals and Clinics.
Wyeth anticipated this and is testing a second-generation vaccine. But it is at least two years from reaching the market, and the new strains could become a public health problem in the meantime if they spread hard-to-treat infections through day-care centers and schools.
“I don’t think the new strains are moving fast enough to call it a race, but the fact is that certain strains are increasing,” said Peter Paradiso, a scientist at Wyeth Vaccines, the Collegeville, Pa., division that makes Prevnar.
“It is very worrying,” said Dr. Keith Klugman, an infectious diseases specialist at Emory University. “With the eradication of all the other types in the vaccine, this one is emerging.”
Several research teams reported on the situation Monday at microbiologists meeting.
Associated Press 17th September 2007.
http://www.msnbc.msn.com/id/20825107/#storyContinued
Introduction of NEW TYPE of pneumonia following introduction of Prevnar vaccine
The nasopharyngeal (NP) prevalence of the 6C serotype was determined using 1326 pneumococcal isolates collected from 7 cohorts of Massachusetts children between 1994 and 2007. Initially, the isolates were serotyped using the quellung reaction; subsequently, stored specimens of all putative 6A isolates were tested for 6C using monoclonal antibodies. The opsonophagocytic and antibiotic susceptibilities of the isolates were determined.
Conclusions. Among NP isolates, the prevalence of 6C isolates has increased and the prevalence of 6A isolates has decreased since the introduction of PCV7 in Massachusetts in 2000. The observed increase in serotype 6C prevalence may be explained by the induction by PCV7 of low amounts of functional anti-6C antibody, compared with anti-6A and anti-6B antibodies.
Put in plain English, a new type of pneumonia called 6C has occured and cases have been increasing since the introduction of Prevnar (PCV7).
Source: The Journal of Infectious Diseases 2009;199:320–325.
Pneumococcal vaccine does not appear to protect against pneumonia
We included 22 trials involving 101 507 participants: 11 trials reported on presumptive pneumococcal pneumonia, 19 on all-cause pneumonia and 12 on all-cause mortality. The current 23-valent vaccine was used in 8 trials. The relative risk (RR) was 0.64 (95% confidence interval [CI] 0.43–0.96) for presumptive pneumococcal pneumonia and 0.73 (95% CI 0.56–0.94) for all-cause pneumonia. There was significant heterogeneity between the trials reporting on presumptive pneumonia (I2 = 74%, p < 0.001) and between those reporting on all-cause pneumonia (I2 = 90%, p < 0.001). The RR for all-cause mortality was 0.97 (95% CI 0.87–1.09), with moderate heterogeneity between trials (I2 = 44%, p = 0.053). Trial quality, especially regarding double blinding, explained a substantial proportion of the heterogeneity in the trials reporting on presumptive pneumonia and all-cause pneumonia. There was little evidence of vaccine protection in trials of higher methodologic quality (RR 1.20, 95% CI 0.75–1.92, for presumptive pneumonia; and 1.19, 95% CI 0.95–1.49, for all-cause pneumonia in double-blind trials; p for heterogeneity > 0.05). The results for all-cause mortality in double-blind trials were similar to those in all trials combined. There was little evidence of vaccine protection among elderly patients or adults with chronic illness in analyses of all trials (RR 1.04, 95% CI 0.78–1.38, for presumptive pneumococcal pneumonia; 0.89, 95% CI 0.69–1.14, for all-cause pneumonia; and 1.00, 95% CI 0.87–1.14, for all-cause mortality).
Interpretation: Pneumococcal vaccination does not appear to be effective in preventing pneumonia, even in populations for whom the vaccine is currently recommended.
Source: CMAJ • January 6, 2009; 180 (1). doi:10.1503/cmaj.080734.
Boy Catches Pneumonia After THREE Doses Of Prevnar And They Don’t Think Antibodies Can Protect The Individual
We measured the concentration, opsonic activity, and avidity of serotype-specific serum antibodies in a pneumococcal conjugate vaccine (PnCRM7) efficacy trial participant who contracted serotype 14 pneumococcal bacteremia following dose 3 of PnCRM7. Controls included 18 PnCRM7- and 10 MnCC-vaccinated children without invasive pneumococcal disease (IPD). The child with vaccine failure had 4.98 mcg/mL of serotype 14 antibodies 10 days before disease onset; these antibodies had greater opsonic activity and lower avidity than those of control PnCRM7 recipients. The child had no booster response to a fourth dose of PnCRM7 for most vaccine serotypes. We conclude that antibody concentration, functional activity and avidity do not predict individual protection against IPD, and immunological correlates of protection are only useful at the population level.
Source:
Vaccine, Volume 27, Issue 12, 13 March 2009, Pages 1863-1868.
70% Increase in Severe Lung Diseases After Prevnar Vaccine
To determine if the incidence of empyema among children in the United States has changed since the introduction of the pneumococcal conjugate vaccine in 2000.
METHODS: We used the nationally representative Kids’ Inpatient Database to estimate the annual total number of hospitalizations of children ≤18 years of age that were associated with empyema in 1997, 2000, 2003, and 2006. Using US Census data, estimated counts were converted into annual incidence rates per 100000 children. Incidence rates were compared between 1997 and later years to determine the impact of pneumococcal conjugate vaccine on hospitalization rates.
RESULTS: During 2006, an estimated total of 2898 (95% confidence interval [CI]: 2532–3264) hospitalizations of children ≤18 years of age in the United States were associated with empyema. The empyema-associated hospitalization rate was estimated at 3.7 (95% CI: 3.3–4.2) per 100000 children, an increase of almost 70% from the 1997 empyema hospitalization rate of 2.2 (95% CI: 1.9–2.5) per 100000. The rate of complicated pneumonia (empyema, pleural effusion, or bacterial pneumonia requiring a chest tube or decortication) similarly increased 44%, to 5.5 (95% CI: 4.8–6.1) per 100000. The rate of bacterial pneumonia decreased 13%, to 244.3 (95% CI: 231.1–257.5) per 100000. The rate of invasive pneumococcal disease (pneumonia, sepsis, or meningitis caused by Streptococcus pneumoniae) decreased 50%, to 6.3 (95% CI: 5.7–6.9) per 100000.
CONCLUSIONS: Among children ≤18 years of age, the annual empyema-associated hospitalization rates increased almost 70% between 1997 and 2006, despite decreases in the bacterial pneumonia and invasive pneumococcal disease rates. Pneumococcal conjugate vaccine is not decreasing the incidence of empyema.
Source: PEDIATRICS Vol. 125 No. 1 January 2010, pp. 26-33
http://pediatrics.aappublications.org/cgi/content/abstract/125/1/26
Pneumococcal conjugate vaccination and nasopharyngeal acquisition of pneumococcal serotype 19A strains
Abstract
CONTEXT: The rapid increase in multiresistant serotype 19A as a cause of invasive and respiratory pneumococcal disease has been associated in time with the widespread implementation of 7-valent pneumococcal conjugate vaccination (PCV-7) in several countries. Because spontaneous fluctuations in time and antibiotic selective pressure may have induced this serotype 19A increase, controlled studies are needed to assess the role of PCV-7.
OBJECTIVE: To examine the association of PCV-7 vaccination and nasopharyngeal acquisition of serotype 19A pneumococci, their clonal distribution, and antibiotic susceptibility.
DESIGN, SETTING, AND PATIENTS: Post hoc per-protocol completer’s analysis as part of a randomized controlled trial of nasopharyngeal Streptococcus pneumoniae carriage enrolling 1003 healthy newborns with follow-up to the age of 24 months in The Netherlands, which has low antibiotic resistance rates. The study was conducted before widespread PCV-7 implementation in infants, between July 7, 2005, and February 14, 2008. Nasopharyngeal swabs were obtained at the age of 6 weeks and at 6, 12, 18, and 24 months.
INTERVENTION: Infants were randomly assigned to receive 2 doses of PCV-7 at 2 and 4 months; 2 + 1 doses of PCV-7 at 2, 4, and 11 months; or no dosage (unvaccinated control group).
MAIN OUTCOME MEASURE: Cumulative proportion of children with nasopharyngeal acquisition of a new serotype 19A strain from 6 through 24 months of age.
RESULTS: Nine hundred forty-eight children completed the study. Fifty-four nasopharyngeal serotype 19A carriage isolates from 318 in the 2-dose group, 66 isolates from 327 in the 2 + 1-dose group, and 33 isolates from 303 in the unvaccinated were collected from 6 weeks through 24 months. The cumulative proportion who tested positive for new nasopharyngeal serotype 19A acquisition from 6 through 24 months of age was significantly higher in those having received the 2 + 1-dose PCV-7 schedule (16.2%; 95% confidence interval [CI], 12.6%-20.6%) vs those who were unvaccinated (9.2%; 95% CI, 6.5%-13.0%; relative risk [RR], 1.75; 95% CI, 1.14-2.70) but not after a 2-dose schedule (13.2%; 95% CI, 9.9%-17.4%; RR, 1.43; 95% CI, 0.91-2.25). There were 28 different sequence types identified, including 6 new types. The proportion of children with new 19A acquisition who had used antibiotics in the last 6 months (18.7%) did not differ among groups. Five isolates were penicillin-intermediate susceptible and another 3 were nonsusceptible to erythromycin and azithromycin, all in the vaccine groups.
CONCLUSION: A 2 + 1-dose PCV-7 schedule was associated with an increase in serotype 19A nasopharyngeal acquisition compared with unvaccinated controls.
Source: JAMA. 2010 Sep 8;304(10):1099-106
Significant Increase in non-7 PCV Pneumonia after Prevnar Vaccination
The overall incidence of IPD decreased from 2002 to 2007, primarily driven
by a reduction in IPD caused by 7vPCV serotypes. However, this was partially offset by a
significant increase in the incidence of IPD caused by non-7vPCV serotypes, particularly
19A, in non-Indigenous children.
Source: http://www.mja.com.au/public/issues/194_03_070211/wil10655_fm.pdf
No drop in U.S. kids’ pneumonia rate after vaccine
A childhood vaccine against pneumonia-causing bacteria introduced in 2000 hasn’t made a visible dent in the disease, U.S. researchers said Monday.
In the first study to provide national estimates of childhood pneumonia, they found rates of the lung infection had stayed more or less constant between 1994 and 2007.
At the beginning of that period, 19 in 1,000 children got a pneumonia diagnosis at the doctor’s office or at an emergency department, compared to 22 in 1,000 at the end.
But that doesn’t mean the vaccine — Pfizer’s Prevnar, or PCV7 — has been useless.
For instance, earlier work found the number of kids who had to be treated for pneumonia at the hospital dropped by more than half after the vaccine became available.
“It’s possible that the vaccination has had a major impact on the more serious complications of pneumonia,” said Dr. Samir S. Shah of the University of Pennsylvania School of Medicine in Philadelphia, who led the work.
Prevnar protects against a type of bacteria called Streptococcus pneumoniae, or just pneumococcus, which causes several kinds of infections — including pneumonia, meningitis and middle ear infections.
“If you look at how effective the vaccine was in reducing meningitis and blood infections, it has done a phenomenal job,” said Shah, whose study was supported by the National Institutes of Health.
While Pfizer said Prevnar is not licensed to prevent pneumonia in the U.S., it stressed the new study’s design might be shrouding possible effects of the vaccine on the disease.
Source: Reuters Health, 16th February 2011.
Complicated Pneumococcal Meningitis in a Fully Vaccinated Child
We present a unique case of life-threatening pneumococcal meningitis complicated by vasculitis in a fully vaccinated 4-year-old female with the heptavalent conjugate vaccine for Streptococcus pneumoniae (PCV7). Serotype 23F was isolated in both blood and cerebral spinal fluid (CSF) samples. Pulses of methylprednisolone were promptly initiated in addition to antibiotics leading to a good recovery. CSF studies and magnetic resonance imaging (MRI) of the brain were used for diagnosis and monitoring the response to corticoid therapy. We report the investigations of a child with failure of PCV7 vaccine to protect against vaccine-serotype invasive disease. Use of corticosteroids and temporal association with changes in brain imaging are described for the first time in literature.
Source: Neuropediatrics. 2011 Nov 14. http://www.ncbi.nlm.nih.gov/pubmed/22083882
Streptococcus pneumoniae meningitis in a child vaccinated with pneumococcal heptavalent conjugate vaccine
Pneumococcal meningitis is still today a life threatening disease among children under-5 worldwide. Although the heptavalent vaccine has demonstrated its ability to reduce the incidence of pneumococcal disease its efficacy is limited due to the restricted number of serotypes included. We report a case of a child with a Streptococcus pneumoniae meningitis despite the use of heptavalent conjugate vaccine.
Source: New Microbiol. 2009 Jul;32(3):317-8. http://www.ncbi.nlm.nih.gov/pubmed/19845117
