The heptavalent pneumococcal polysaccharide-CRM197 conjugate vaccine is safe and efficacious in the prevention of acute otitis media caused by the serotypes included in the vaccine.

No abstract

Neisseria meningitidis is one of the leading causes of bacterial meningitis globally and can also cause sepsis, pneumonia, and other manifestations. In countries with high endemic rates, the disease burden places an immense strain on the public health system. The worldwide epidemiology of invasive meningococcal disease (IMD) varies markedly by region and over time. This review summarizes the burden of IMD in different countries and identifies the highest-incidence countries where routine preventive programs against Neisseria meningitidis would be most beneficial in providing protection. Available epidemiological data from the past 20 years in World Health Organization and European Centre for Disease Prevention and Control collections and published articles are included in this review, as well as direct communications with leading experts in the field. Countries were grouped into high-, moderate-, and low-incidence countries. The majority of countries in the high-incidence group are found in the African meningitis belt; many moderate-incidence countries are found in the European and African regions, and Australia, while low-incidence countries include many from Europe and the Americas. Priority countries for vaccine intervention are high- and moderate-incidence countries where vaccine-preventable serogroups predominate. Epidemiological data on burden of IMD are needed in countries where this is not known, particularly in South- East Asia and Eastern Mediterranean regions, so evidence-based decisions about the use of meningococcal vaccines can be made.

Because of the advent of a new influenza A H1N1 strain, many countries have begun mass immunisation programmes. Awareness of the background rates of possible adverse events will be a crucial part of assessment of possible vaccine safety concerns and will help to separate legitimate safety concerns from events that are temporally associated with but not caused by vaccination. We identified background rates of selected medical events for several countries. Rates of disease events varied by age, sex, method of ascertainment, and geography. Highly visible health conditions, such as Guillain-Barré syndrome, spontaneous abortion, or even death, will occur in coincident temporal association with novel influenza vaccination. On the basis of the reviewed data, if a cohort of 10 million individuals was vaccinated in the UK, 21·5 cases of Guillain-Barré syndrome and 5·75 cases of sudden death would be expected to occur within 6 weeks of vaccination as coincident background cases. In female vaccinees in the USA, 86·3 cases of optic neuritis per 10 million population would be expected within 6 weeks of vaccination. 397 per 1 million vaccinated pregnant women would be predicted to have a spontaneous abortion within 1 day of vaccination.

To assess the efficacy of a 7-valent pneumococcal polysaccharide-meningococcal outer membrane protein complex conjugate vaccine (PncOMPC) against acute otitis media (AOM), 1666 infants were randomly assigned to receive either PncOMPC or control vaccine (hepatitis B vaccine) at 2, 4, 6, and 12 months of age. Of the 835 children assigned to receive PncOMPC, 187 received a 23-valent pneumococcal polysaccharide vaccine (PncPS) at 12 months of age instead. Whenever AOM was diagnosed, middle ear fluid was aspirated for bacterial culture. In the PncOMPC and control groups, there were 110 and 250 AOM episodes, respectively, in children between 6.5 and 24 months of age that could be attributed to vaccine serotypes, which indicates a vaccine efficacy of 56% (95% confidence interval, 44%-66%). The serotype-specific efficacy ranged from 37% for 19F to 82% for 9V. The 2 boosters seemed to provide equal protection against AOM, but PncPS induced markedly higher antibody concentrations. The efficacy of PncOMPC was comparable to that of the recently licensed pneumococcal conjugate vaccine.

The oropharyngeal carriage of Haemophilus influenzae type b (Hib) was studied among 725 healthy 3-year-old children who had or had not been immunized with an Hib conjugate vaccine. Oropharyngeal swabs were collected during the childrens' well-child visit to their local child health center. Fourteen (3.5%) of the 398 unvaccinated children were oropharyngeal carriers of Hib, whereas none of the 327 children who had received Hib conjugate vaccine carried Hib (P less than .001). Carriage rates of non-type b H. influenzae (19%) or Streptococcus pneumoniae (18%) were the same irrespective of the Hib vaccination status of the children. Thus Hib conjugate vaccine, unlike Hib polysaccharide vaccine, seems to be able to prevent oropharyngeal colonization by Hib.

A new conjugate vaccine consisting of the capsular polysaccharide of H. influenzae type b covalently linked to a protein carrier (PRP-D), administered to infants beginning at the age of 3 months, is highly effective in protecting young Finnish children (7 to 24 months old) against invasive H. influenzae type b infections.

No abstract