New data show no advantage of cell-based over egg-based flu vaccine
Cell culture–based inactivated influenza vaccine (ccIIV) was not significantly more effective than egg-based IIV (ebIIV) against influenza A during the 2017-18 flu season, according to new data presented at IDWeek that have not been peer reviewed.
Researchers examined data from 3,015,891 Kaiser Permanente members ages 4 through 64 years, 1,017,314 of whom (33.7%) were vaccinated with either ebIIV or Flucelvax, the ccIIV. Of those vaccinated, 91.7% received ebIIV and 8.3% received ccIIV.
Adjusted vaccine effectiveness (VE) against all flu strains was 30.2% for ccIIV and 17.9% for ebIIV. Comparing the two vaccine types, ccIV had a 6.8% higher VE, but the difference was not statistically significant, the investigators reported.
"Both cell-culture and egg-based IIV vaccines showed relatively low effectiveness during the 2017-2018 influenza season in which A(H3N2) predominated," the researchers concluded. "The findings of this study show there was no significant difference in the effectiveness of cell-culture IIV compared with egg-based IIVs. Improvements in influenza vaccines will require ongoing monitoring of vaccine effectiveness."
Oct 6 IDWeek abstract
Study: Tdap vaccine in pregnancy leads to more antibodies for baby
A study today in the Journal of the American Medical Association (JAMA) shows that infants born to women who had the tetanus, diphtheria, and pertussis (Tdap) vaccine in the third trimester of pregnancy had significantly higher concentrations of pertussis toxin antibodies in cord blood compared with controls.
Currently, all US women are recommended to get the Tdap vaccine during weeks 27 through 36 of pregnancy to prevent life-threatening infant pertussis, or whooping cough. To conduct the study, researchers at a Houston hospital monitored 626 pregnancies in which 312 women received the Tdap vaccine.
In the Tdap-exposed group, the geometric mean concentration of pertussis toxin antibodies in cord blood wa 47.3 international units per milliliter (IU/mL), versus 12.9 IU/mL in the non-vaccine group, a difference that was statistically significant.
The authors also said that more Tdap-exposed than Tdap-unexposed neonates had pertussis toxin antibody concentrations of 15 IU/mL or higher (86% vs 37%; difference, 49% [95% confidence interval (CI), 42%-55%]), 30 IU/mL or higher (72% vs 17%; difference, 55% [95% CI, 49%-61%]), and 40 IU/mL or higher (59% vs 12%; difference, 47% [95% CI, 41%-54%]); P < .001 for each analysis.
"Pertussis toxin is the pertussis antigen most associated with severe infant disease. Although no definitive serologic correlate of immunity for pertussis has been established, it is likely that antibody concentrations needed to protect young infants are higher than those required for older children and adults," the authors concluded.
Oct 9 JAMA study
UK Parliament group urges lower antibiotic use in animals
The UK Parliamentary Office of Science and Technology (POST) released a report yesterday on the country's current use of antibiotics in animals and options for reducing use, including better animal husbandry and improved housing for livestock.
The POST report notes that UK antibiotic use in animals declined 22% from 2011 to 2014, but the authors note that more work is needed to meet targets set for 2020. They note that antibiotic use varies widely across sectors, with the pig industry being the highest user but also showing the greatest gains. Overall antibiotic use in this sector has dropped 50% since 2015.
The report also notes that antibiotics considered critical for human medicine make up 39% of antibiotic prescriptions for cats and 5.4% of antibiotic prescriptions for dogs in Britain.
"Approaches to reducing antibiotic use in animals include better animal husbandry, improved housing, better herd/flock management, vaccination and disease eradication," the authors wrote. "Enacting change involves managing the expectations that people who use vets (clients such as farmers or pet owners) have of being prescribed antibiotics when their animals are ill."