FDA approves Sanofi-Merck vaccine against 6 childhood diseases
Sanofi announced yesterday that the US Food and Drug Administration (FDA) has approved Vaxelis, a combination vaccine targeting six diseases.
The vaccine is designed to prevent diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, and invasive disease due to Haemophilus influenzae type b. It is administered intramuscularly as a 3-dose series in babies at age 2, 4, and 6 months of age. However, the regimen doesn't cover a primary immunization series against pertussis, and an additional dose of pertussis-containing vaccine is needed to complete the series.
In its statement, Sanofi said the vaccine is the result of a partnership with Merck formed in 1991 and maximizes both companies' experience developing, manufacturing, and marketing individual and combination vaccines. It added that the vaccine won't be available commercially before 2020.
Dec 26 Sanofi statement
Study links malaria in early pregnancy to placental vascular changes
Malaria infection in the first pregnancy trimester, before preventive treatment is given and insecticide-treated bed nets are used, can impede placental development and result in low birthweight and earlier births, researchers from Denmark and Tanzania reported today in the Journal of Infectious Diseases.
The team conducted the longitudinal study in Tanzania between 2014 and 2016, enrolling 538 women. The investigation included preconception and early pregnancy cohorts, and researchers used stereography to examine 138 placentas collected at birth, focusing on placental villi and vessels.
Compared to controls, women infected with malaria before 15 weeks gestation had decreased transport villi volume, increased diffusion distance in diffusion vessels, and a compensatory increase in diffusion vessel surface. Researchers also found that first two changes were positive predictors for birth weight and gestational age at delivery.
The team concluded that malaria infection during early pregnancy had a negative effect on placental vascular development and pregnancy outcomes.
In an editorial in the same issue, two infectious disease experts wrote that though it's known that malaria in early pregnancy is harmful, it's not known how early the increase in risk manifests. They said the changes the authors saw were most notable before 15 week's gestation, but were less pronounced at between 15 and 22 weeks. Factoring in the anatomic changes and associations with birth weight and gestational length changes, "these data suggest that malaria infection in the first trimester of pregnancy can have lasting effects on placental development, which seem to affect pregnancy outcomes," the authors wrote. They include Stephen Rogerson, MBBS, PhD, with the University of Melbourne, and Steven Meshnick, MD, PhD, with the University of North Carolina at Chapel Hill.
They pointed out a few caveats, such as the relatively small size of the study, in which 68 of the women were infected with malaria, and that women infected in the first trimester were treated with quinine instead of artemisinin combination therapy, which could have confounded the findings.
"Nevertheless, this study clearly indicates a need to look more closely at the consequences of malaria in the first trimester of pregnancy and, possibly, to evaluate interventions to protect pregnant women during this period," they wrote.
Dec 27 J Infect Dis abstract
Dec 27 J Infect Dis editorial