Phase 2 trial shows high efficacy for malaria vaccine candidate
The results of a phase 2b clinical trial indicate 77% efficacy over 12 months of follow-up for a vaccine that targets malaria caused by Plasmodium falciparum, according to a preprint study published this week in The Lancet.
The low-dose circumsporozite protein-based vaccine (R21) developed by researchers with Oxford University, in collaboration with Novavax and Serum Institute of India, was tested with two different doses of Matrix-M (MM) adjuvant in 450 children ages 5 to 17 months in Nanoro, Burkina Faso, a highly seasonal malaria transmission setting. Three vaccinations were administered at 4-week intervals prior to and during the start of the malaria season, with a fourth dose given 1 year later. Investigators in the randomized, controlled, double-blind trial evaluated safety, immunogenicity, and efficacy with the high- and low-dose adjuvants and compared the results with a control group that received a rabies vaccine.
At 6 months, 33 of 146 (29.5%) children who received R21/MM with low-dose adjuvant and 38/146 (26%) who received R21/MM with high-dose adjuvant developed malaria, compared with 105/147 (71.4%) who received the rabies vaccine. Vaccine efficacy (VE) was 74% and 77% in the low- and high-dose adjuvant groups, respectively, and at 1 year, VE remained at 77% in the high-dose adjuvant group.
Both adjuvant dosage levels were well tolerated, with fever the most common adverse event reported. No severe adverse reactions were reported.
The investigators note that R21/MM is the first malaria vaccine candidate to meet the World Health Organization’s Malaria Vaccine Technology Roadmap goal of at least 75% efficacy. Recruitment for a phase 3 trial in children in four African countries has begun.
“These are very exciting results showing unprecedented efficacy levels from a vaccine that has been well tolerated in our trial programme,” principal trial investigator Halidou Tinto, PhD, of the Institute for Health Sciences Research in Nanoro said in a University of Oxford press release. “We look forward to the upcoming phase III trial to demonstrate large-scale safety and efficacy data for a vaccine that is greatly needed in this region.”
There were an estimated 229 million cases of malaria worldwide in 2019, with 409,000 deaths. Children under the age of 5 accounted for 67% of those deaths.
Apr 20 Lancet preprint abstract
Apr 23 University of Oxford press release
Bacterial coinfection common in hospitalized flu patients, study finds
Analysis of a large sample of US inpatients hospitalized with influenza and community-acquired pneumonia (CAP) found that bacterial coinfection occurred in more than 10% of flu patients and that flu patients with bacterial coinfection had worse outcomes, researchers reported today in Infection Control & Hospital Epidemiology.
Because evidence from previous pandemic influenza seasons has shown that bacterial coinfections in hospitalized flu patients are common, guidelines from the Infectious Diseases Society and the American Thoracic Society recommend that inpatients diagnosed with influenza also receive empiric antibiotics. To help guide the choice of empiric antibiotic therapy, researchers from the Cleveland Clinic, Harvard Medical School, and the University of Massachusetts evaluated the frequency of bacterial coinfection and the distribution of bacterial pathogens over time in a national sample of inpatients during nonpandemic years. They also compared outcomes in patients with and without coinfection.
Among 38,665 patients hospitalized with CAP at 179 US hospitals from July 2010 through June 2015, 4,313 (11.2%) tested positive for influenza within 3 days of admission. In the first 3 hospital days, patients who tested positive for influenza were less likely than those who tested negative to have an identified bacterial infection (10.3% vs 16.2%), and the cultures of patients who tested positive for influenza were more likely to contain Staphylococcus aureus (34.2% vs 28.8%) and less likely to contain Streptococcus pneumoniae (24.9% vs 31.0%). Of the S aureus isolates, the proportion that were methicillin resistant (MRSA) was lower among influenza-positive patients than among influenza-negative patients (42.8% vs 53.2%). After day 3, pathogens for both groups were similar.
Bacterial coinfection in influenza-positive patients was associated with increased odds of in-hospital mortality (adjusted odds ratio [aOR], 3.00; 95% confidence interval [CI], 2.17 to 4.16), late ICU transfer (aOR, 2.83; 95% CI, 1.98 to 4.04), and higher cost (risk-adjusted mean multiplier, 1.77; 95% CI, 1.59 to 1.96).
“In conclusion, during nonpandemic years, influenza infection resulting in hospitalization is frequently accompanied by bacterial coinfection,” the study authors wrote. “Treatment with empiric antibiotics, at least for the first 2 days while awaiting maturation of clinical cultures and assessing patient response, is appropriate.”
They add that since most S aureus strains in flu patients were not methicillin-resistant, antibiotic coverage for MRSA is not routinely warranted.
Apr 23 Infect Control Hosp Epidemiol abstract
CDC: New Salmonella outbreak linked to cashew brie
The Centers for Disease Control and Prevention (CDC) said today it is reinvestigating an outbreak of Salmonella linked to a brand of vegan brie cheese made from cashews.
So far, five people in three states—California, Tennessee, and Florida—have been sickened from Jule’s cashew brie, including two people who were hospitalized. No deaths have been reported.
“Officials from California and Tennessee collected samples of Jule’s cashew brie for testing. On April 22, testing results showed that the samples of all varieties of Jule’s cashew brie collected in California were contaminated with Salmonella,” the CDC said.
Yesterday, Jule’s Foods of Carlsbad, California, voluntarily recalled all products with all expiration dates, including three types of cashew brie, a spinach dip, and vegan ranch dressing.
According to the Food and Drug Administration (FDA), products were distributed to primarily independently owned grocery stores in Arkansas, California, Colorado, Connecticut, Florida, Louisiana, Maryland, Minnesota, Nevada, New York, New Jersey, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, and Texas as well as directly to consumers via online orders.
Apr 23 CDC update
Apr 22 FDA recall notice