Background

Rotaviruses are the most important cause of severe acute gastroenteritis worldwide in children <5 years of age. The human, G1P[8] rotavirus vaccine Rotarix™ significantly reduced severe rotavirus gastroenteritis episodes in a Phase III clinical trial conducted in infants in South Africa and Malawi. This paper examines rotavirus vaccine efficacy in preventing severe rotavirus gastroenteritis, during infancy, caused by the various G and P rotavirus types encountered during the first rotavirus-season.

Methods

Healthy infants aged 5–10 weeks were enrolled and randomized into three groups to receive either two (10 and 14 weeks) or three doses of Rotarix™ (together forming the pooled Rotarix™ group) or three doses of placebo at a 6,10,14-week schedule. Weekly home visits were conducted to identify gastroenteritis episodes. Rotaviruses were detected by ELISA and genotyped by RT-PCR and nucleotide sequencing. The percentage of infants with severe rotavirus gastroenteritis caused by the circulating G and P types from 2 weeks post-last dose until one year of age and the corresponding vaccine efficacy was calculated with 95% CI.

Results

Overall, 4939 infants were vaccinated and 4417 (pooled Rotarix™ = 2974; placebo = 1443) were included in the per protocol efficacy cohort. G1 wild-type was detected in 23 (1.6%) severe rotavirus gastroenteritis episodes from the placebo group. This was followed in order of detection by G12 (15 [1%] in placebo) and G8 types (15 [1%] in placebo). Vaccine efficacy against G1 wild-type, G12 and G8 types were 64.1% (95% CI: 29.9%; 82%), 51.5% (95% CI:-6.5%; 77.9%) and 64.4% (95% CI: 17.1%; 85.2%), respectively. Genotype P[8] was the predominant circulating P type and was detected in 38 (2.6%) severe rotavirus gastroenteritis cases in placebo group. The remaining circulating P types comprised of P[4] (20 [1.4%] in placebo) and P[6] (13 [0.9%] in placebo). Vaccine efficacy against P[8] was 59.1% (95% CI: 32.8%; 75.3%), P[4] was 70.9% (95% CI: 37.5%; 87.0%) and P[6] was 55.2% (95% CI: -6.5%; 81.3%)

Conclusions

Rotarix™ vaccine demonstrated efficacy against severe gastroenteritis caused by diverse circulating rotavirus types. These data add to a growing body of evidence supporting heterotypic protection provided by Rotarix™.

Trial registration number

NCT00241644

A cross-sectional study was performed in children 5 through 10 years of age presenting to outpatient clinics in Nyanza Province, Kenya, in which nasal swab and blood specimens were collected during the high malaria transmission season. Patients presenting with malaria-like symptoms within 4 days of fever onset were enrolled in the study. Plasmodium parasitemia was determined by blood smear microscopy. Nasal swabs were screened for a panel of respiratory viruses by polymerase chain reaction. Influenza A, rhinoviruses, and other respiratory viruses were detected in 18%, 26%, and 12% of 197 specimens, respectively. Four of 36 patients with influenza A had a positive malaria blood slide, compared with 20 of 52 patients with rhinovirus. A significant burden of disease caused by influenza A in febrile children during the study period was observed, highlighting the need for further research into the burden of influenza disease in regions where malaria is holoendemic.

SYNOPSIS

Objectives

Household contacts of people at high risk for influenza complications should receive yearly influenza vaccination to reduce potential viral transmission. We evaluated influenza vaccine coverage among children to determine whether or not living with a high-risk adult predicts the likelihood of being vaccinated.

Methods

Using the 2006 National Health Interview Survey, we examined influenza vaccination rates among children (aged 1–17 years) who did and did not reside in a household with an adult at high risk for influenza-related complications.

Results

Among 24,195 sampled families, there were 8,976 high-risk adults, 18.9% of whom reported living with a person 17 years of age of younger. Influenza vaccination rates by age group among children living with high-risk adults were 41.7% (1 year), 30.3% (2–4 years), and 20.0% (5–17 years). Unadjusted influenza vaccination rates were significantly higher for school-aged children who lived with a high-risk adult compared with those who did not (20.0% vs. 15.0%, p<0.001). Among children younger than 5 years of age, for whom vaccination was universally recommended at the time of the survey, the rates did not differ. After adjusting for the child's age, gender, race, insurance coverage, medical visits, and chronic conditions, children who lived with a high-risk adult were not statistically more likely than those who did not live with a high-risk adult to receive influenza vaccination (odds ratio = 1.16, 95% confidence interval 0.99, 1.36).

Conclusions

Children had low rates of influenza vaccination, and those who lived with high-risk adults were not significantly more likely to be vaccinated. Clinicians caring for high-risk adults should remind eligible household contacts to receive influenza vaccine.

Background

Google Flu Trends was developed to estimate US influenza-like illness (ILI) rates from internet searches; however ILI does not necessarily correlate with actual influenza virus infections.

Methods and Findings

Influenza activity data from 2003–04 through 2007–08 were obtained from three US surveillance systems: Google Flu Trends, CDC Outpatient ILI Surveillance Network (CDC ILI Surveillance), and US Influenza Virologic Surveillance System (CDC Virus Surveillance). Pearson's correlation coefficients with 95% confidence intervals (95% CI) were calculated to compare surveillance data. An analysis was performed to investigate outlier observations and determine the extent to which they affected the correlations between surveillance data. Pearson's correlation coefficient describing Google Flu Trends and CDC Virus Surveillance over the study period was 0.72 (95% CI: 0.64, 0.79). The correlation between CDC ILI Surveillance and CDC Virus Surveillance over the same period was 0.85 (95% CI: 0.81, 0.89). Most of the outlier observations in both comparisons were from the 2003–04 influenza season. Exclusion of the outlier observations did not substantially improve the correlation between Google Flu Trends and CDC Virus Surveillance (0.82; 95% CI: 0.76, 0.87) or CDC ILI Surveillance and CDC Virus Surveillance (0.86; 95%CI: 0.82, 0.90).

Conclusions

This analysis demonstrates that while Google Flu Trends is highly correlated with rates of ILI, it has a lower correlation with surveillance for laboratory-confirmed influenza. Most of the outlier observations occurred during the 2003–04 influenza season that was characterized by early and intense influenza activity, which potentially altered health care seeking behavior, physician testing practices, and internet search behavior.