Study finds heat-stable rotavirus vaccine effective in preschoolers in Niger
An inexpensive heat-stable rotavirus vaccine was shown to be 67% effective in a resource-poor setting in Africa, providing renewed hope for addressing the deadly diarrhea-causing disease in children, a study today in the New England Journal of Medicine reported.
Rotavirus is responsible each year for about 37% of deaths from diarrhea in children younger than 5 years old globally, or about 450,000 children, with a disproportionate high number in sub-Saharan Africa. Two rotavirus vaccines were approved for use by the World Health Organization in 2008, but they require cold storage and have proved rather expensive—about $4.50 to $10.50 per dose.
The authors of today's study used a live, oral pentavalent (five-strain) rotavirus vaccine, called BRV-PV and made by the Serum Institute of India. The vaccine is thermostable for 24 months at 98.6°F (37°C) and for 6 months at 104°F (40°C), which could prove helpful in remote areas where cold-chain storage is limited. BRV-PV costs $2.50 per dose, according to a Doctors Without Borders (MSF) news release on the study.
In today's study, researchers from Harvard University and Epicentre, MSF's research center in Paris, included 3,508 healthy infants in Niger who received three doses of BRV-PV or a placebo at 6, 10, and 14 weeks of age.
The authors reported 31 cases of severe rotavirus gastroenteritis in the vaccine group and 87 in the placebo group, for a vaccine efficacy of 66.7% (95% confidence interval, 49.9% to 77.9%). Adverse events between the two groups did not differ significantly, and there were 27 deaths in the vaccine group and 22 in the placebo group. None of the infants had confirmed intussusception, a telescoping of the intestine that has been associated with rotavirus vaccines.
"This trial brings a vaccine which is adapted to African settings to those who need it most," said first author Sheila Isanaka, ScD, assistant professor of nutrition at Harvard's T.H. Chan School of Public Health, in a Harvard news release. "When the vaccine becomes widely available in Africa, it will help protect millions of the most vulnerable children." MSF Medical Director Micaela Serafini, MD, MPH, in the MSF release, called the vaccine a "game-changer."
In an accompanying editorial, Mathuram Santosham, MD, MPH, of Johns Hopkins, and Duncan Steele, PhD, of the Bill and Melinda Gates Foundation, write that the 67% efficacy is similar to that of other rotavirus vaccines in similar settings. They add, "Despite this modest efficacy, the absolute public health benefits of vaccination are large, given the tremendous disease burden."
The vaccine is also being tested in India.
Mar 22 N Engl J Med study
Mar 22 N Engl J Med editorial
Mar 22 MSF news release
Mar 22 Harvard news release
Study: South America Zika attack rates lower than in French Polynesia
A study yesterday in Scientific Reports found that attack rates of Zika varied from 78% in French Polynesia to 21% in Colombia and 32% in the state of Bahia, Brazil.
In this comparison study, researchers contrasted numbers from the 2013-14 French Polynesia outbreak with data collected 1 year after the current Zika outbreak began in Colombia and Brazil. For all three locations, Zika infection rates reached their peak within the first 6 months of disease detection, and the first wave of the disease was underreported.
Using a mathematical model, the researchers estimated a 78% attack rate in French Polynesia, among children ages 6 to 16. The rates were significantly less in Colombia and Brazil, despite research suggesting that the outbreaks in those countries came from the same strain of Zika seen in French Polynesia.
"The low attack rate in Colombia implies that parts of population were not infected during the 2015-16 ZIKV outbreak, hence a second wave of the epidemic could sweep the country," the authors write. "The lower attack rate in Colombia could partly be due to higher altitude and cooler weather than the other places."
Mar 21 Sci Rep study
USDA steps up Brazilian beef inspections over scandal allegations
In the wake of Brazilian police allegations that several of the country's meat producers bribed inspectors to allow the sale of rotten and Salmonella-contaminated meat, the US Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) said today it is taking extra steps to protect the US food supply.
The FSIS said though none of the facilities identified in Brazil's scandal have shipped meat products to the United States, it immediately instituted extra pathogen tests for all shipments of raw beef and ready-to-eat products from Brazil. The FSIS has also increased examination of all of the products at ports of entry. "The agency will indefinitely maintain its 100% reinspection and pathogen testing of all lots of FSIS-regulated products imported from Brazil." The statement noted that re-inspection of all Brazilian beef took effect on Mar 18.
Mike Young, the USDA's acting deputy secretary, said, "FSIS has strengthened the existing safeguards that protect the American food supply as a precaution and is monitoring the Brazilian government's investigation closely."
On Mar 17, Brazilian police released the results of a 2-year investigation that implicated two major companies, BRF SA (the world's largest poultry producer), JBS SA (the world's biggest meat producer), and dozens of smaller meatpackers, Reuters reported today. The findings allege that meatpackers paid off inspectors to overlook processing of rotten meat and shipping of exports with traces of Salmonella, as well as to not inspect plants. The companies have denied wrongdoing, and authorities have said no illnesses or deaths have been reported.
Mar 22 USDA press release
Mar 22 Reuters story