Conjugate vaccines for preventing meningococcal C meningitis and septicaemia

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 2: Inactivated Vaccines

BACKGROUND AND AIMS

The effectiveness and safety of vaccinations can be altered by immunosuppressive therapies, and perhaps by inflammatory bowel disease (IBD) itself. These recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in adult and pediatric patients with IBD. This publication focused on inactivated vaccines.

METHODS

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative online platform, and voted on by a multidisciplinary group. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

RESULTS

Consensus was reached on 15 of 20 questions. Recommendations address the following vaccines: Haemophilus influenzae type b, recombinant zoster, hepatitis B, influenza, pneumococcus, meningococcus, tetanus-diphtheria-pertussis, and human papillomavirus. Most of the recommendations for patients with IBD are congruent with the current Centers for Disease Control and Prevention and Canada's National Advisory Committee on Immunization recommendations for the general population, with the following exceptions. In patients with IBD, the panel suggested Haemophilus influenzae type b vaccine for patients older than 5 years of age, recombinant zoster vaccine for adults younger than 50 year of age, and hepatitis B vaccine for adults without a risk factor. Consensus was not reached, and recommendations were not made for 5 statements, due largely to lack of evidence, including double-dose hepatitis B vaccine, timing of influenza immunization in patients on biologics, pneumococcal and meningococcal vaccines in adult patients without risk factors, and human papillomavirus vaccine in patients aged 27-45 years.

CONCLUSIONS

Patients with IBD may be at increased risk of some vaccine-preventable diseases. Therefore, maintaining appropriate vaccination status in these patients is critical to optimize patient outcomes. In general, IBD is not a contraindication to the use of inactivated vaccines, but immunosuppressive therapy may reduce vaccine responses.

Antibiotics for preventing meningococcal infections

BACKGROUND

Meningococcal disease is a contagious bacterial infection caused by Neisseria meningitidis (N. meningitidis). Household contacts have the highest risk of contracting the disease during the first week of a case being detected. Prophylaxis is considered for close contacts of people with a meningococcal infection and populations with known high carriage rates.

OBJECTIVES

To study the effectiveness, adverse events and development of drug resistance of different antibiotics as prophylactic treatment regimens for meningococcal infection.

SEARCH METHODS

We searched CENTRAL 2013, Issue 6, MEDLINE (January 1966 to June week 1, 2013), EMBASE (1980 to June 2013) and LILACS (1982 to June 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs addressing the effectiveness of different antibiotics for: (a) prophylaxis against meningococcal disease; (b) eradication of N. meningitidis.

DATA COLLECTION AND ANALYSIS

Two review authors independently appraised the quality and extracted data from the included trials. We analysed dichotomous data by calculating the risk ratio (RR) and 95% confidence interval (CI) for each trial.

MAIN RESULTS

No new trials were found for inclusion in this update. We included 24 studies; 19 including 2531 randomised participants and five including 4354 cluster-randomised participants. There were no cases of meningococcal disease during follow-up in the trials, thus effectiveness regarding prevention of future disease cannot be directly assessed.Mortality that was reported in one study was not related to meningococcal disease or treatment. Ciprofloxacin (RR 0.04; 95% CI 0.01 to 0.12), rifampin (rifampicin) (RR 0.17; 95% CI 0.13 to 0.24), minocycline (RR 0.28; 95% CI 0.21 to 0.37) and penicillin (RR 0.47; 95% CI 0.24 to 0.94) proved effective at eradicating N. meningitidis one week after treatment when compared with placebo. Rifampin (RR 0.20; 95% CI 0.14 to 0.29), ciprofloxacin (RR 0.03; 95% CI 0.00 to 0.42) and penicillin (RR 0.63; 95% CI 0.51 to 0.79) still proved effective at one to two weeks. Rifampin was effective compared to placebo up to four weeks after treatment but resistant isolates were seen following prophylactic treatment. No trials evaluated ceftriaxone against placebo but rifampin was less effective than ceftriaxone after one to two weeks of follow-up (RR 5.93; 95% CI 1.22 to 28.68). Mild adverse events associated with treatment were observed.

AUTHORS' CONCLUSIONS

Using rifampin during an outbreak may lead to the circulation of resistant isolates. Use of ciprofloxacin, ceftriaxone or penicillin should be considered. All four agents were effective for up to two weeks follow-up, though more trials comparing the effectiveness of these agents for eradicating N. meningitidis would provide important insights.

Prevention of sepsis in children: a new paradigm for public policy

Sepsis is one of the leading causes of death worldwide. While the management of critically ill patients with sepsis is certainly better now compared to 20 years ago, sepsis-associated mortality remains unacceptably high. Annual deaths from sepsis in both children and adults far surpass the number of deaths from acute myocardial infarction (AMI), stroke, or cancer. Given the substantial toll that sepsis takes worldwide, prevention of sepsis remains a global priority. Multiple effective prevention strategies exist. Antibiotic prophylaxis, immunizations, and healthcare quality improvement initiatives are important means through which we may reduce the morbidity and mortality from sepsis around the world. Inclusion of these strategies in a coordinated and thoughtful campaign to reduce the global burden of sepsis is necessary for the improvement of pediatric health worldwide.

Antibiotics for preventing meningococcal infections

BACKGROUND

Meningococcal disease is a contagious bacterial infection caused by Neisseria meningitidis (N. meningitidis). Household contacts have the highest risk of contracting the disease during the first week of a case being detected. Prophylaxis is considered for close contacts of people with a meningococcal infection and populations with known high carriage rates.

OBJECTIVES

To study the effectiveness of different prophylactic treatment regimens.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2011, Issue 2) which contains the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE (January 1966 to May Week 3, 2011), EMBASE (1980 to May 2011) and LILACS (1982 to May 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs addressing the effectiveness of different antibiotics for: (a) prophylaxis against meningococcal disease; (b) eradication of N. meningitidis.

DATA COLLECTION AND ANALYSIS

Two review authors independently appraised the quality and extracted data from the included trials. We analysed dichotomous data by calculating the risk ratio (RR) and 95% confidence interval (CI) for each trial.

MAIN RESULTS

We included 24 studies; 19 including 2531 randomised participants and five including 4354 cluster-randomised participants. There were no cases of meningococcal disease during follow up in the trials, thus effectiveness regarding prevention of future disease cannot be directly assessed.Ciprofloxacin (RR 0.04; 95% CI 0.01 to 0.12), rifampin (rifampicin) (RR 0.17; 95% CI 0.13 to 0.24), minocycline (RR 0.28; 95% CI 0.21 to 0.37) and penicillin (RR 0.47; 95% CI 0.24 to 0.94) proved effective at eradicating N. meningitidis one week after treatment when compared with placebo. Rifampin (RR 0.20; 95% CI 0.14 to 0.29), ciprofloxacin (RR 0.03; 95% CI 0.00 to 0.42) and penicillin (RR 0.63; 95% CI 0.51 to 0.79) still proved effective at one to two weeks. Rifampin was effective compared to placebo up to four weeks after treatment but resistant isolates were seen following prophylactic treatment. No trials evaluated ceftriaxone against placebo but ceftriaxone was more effective than rifampin after one to two weeks of follow up (RR 5.93; 95% CI 1.22 to 28.68). Mild adverse events associated with treatment were observed.

AUTHORS' CONCLUSIONS

Using rifampin during an outbreak may lead to the circulation of resistant isolates. Use of ciprofloxacin, ceftriaxone or penicillin should be considered. All four agents were effective for up to two weeks follow up, though more trials comparing the effectiveness of these agents for eradicating N. meningitidis would provide important insights.

Neonatal and infantile immune responses to encapsulated bacteria and conjugate vaccines

Encapsulated bacteria are responsible for the majority of mortality among neonates and infants. The major components on the surface of these bacteria are polysaccharides which are important virulence factors. Immunity against these components protects against disease. However, most of the polysaccharides are thymus-independent (TI)-2 antigens which induce an inadequate immune response in neonates and infants. The mechanisms that are thought to play a role in the unresponsiveness of this age group to TI-2 stimuli will be discussed. The lack of immune response may be overcome by conjugating the polysaccharides to a carrier protein. This transforms bacterial polysaccharides from a TI-2 antigen into a thymus-dependent (TD) antigen, thereby inducing an immune response and immunological memory in neonates and infants. Such conjugated vaccines have been shown to be effective against the most common causes of invasive disease caused by encapsulated bacteria in neonates and children. These and several other approaches in current vaccine development will be discussed.

Seroprotection against serogroup C meningococcal disease

Is higher if vaccination is given in the second decade of life rather than in the first

Prevention of bacterial meningitis: an overview of Cochrane systematic reviews

Acute bacterial meningitis (ABM) is an acute inflammation of leptomeninges caused by bacteria, and has a case fatality rate of 10-30%. Prevention strategies, such as vaccination and prophylactic antibiotics, can prevent ABM and have substantial public health impact by reducing the disease burden associated with it. The aim of this paper is to summarize the main findings from Cochrane systematic reviews that have considered the evidence for measures to prevent ABM. We assessed the evidence available in the Cochrane Library. We found five Cochrane reviews focused on the prevention of ABM; three with use of vaccination and two with prophylactic antibiotics. Polysaccharide serogroup A vaccine is strongly protective for the first year, against serogroup A meningococcal meningitis in adults and children over 5 years of age. Meningococcal serogroup C conjugate (MCC) vaccine is safe and effective in infants. Haemophilus influenzae type b (Hib) vaccine is safe and effective against Hib-invasive disease at all ages. Ceftriaxone, rifampicin and ciprofloxacin are the most effective prophylactic antibiotics against Neisseria meningitidis. There is sufficient evidence to use polysaccharide serogroup A vaccine to prevent serogroup A meningococcal meningitis, MCC conjugate vaccines to prevent meningococcal C meningitis and Hib conjugate vaccine to prevent Hib infections. More studies are needed to evaluate the effects of Hib conjugate vaccine on mortality. Further, studies are required to compare the relative effectiveness of ceftriaxone, ciprofloxacin and rifampicin in chemoprophylaxis against meningococcal infection.