News Scan for Jul 29, 2021

News brief

Pfizer's COVID vaccine seems safe, effective 6 months later

Vaccine effectiveness (VE) for the Pfizer/BioNTech COVID-19 vaccine against COVID-19 was 91% up to 6 months after the second dose, according to a non–peer-reviewed study published yesterday on the preprint server medRxiv.

The researchers followed 44,060 people 16 and older, randomly assigning half to receive two doses of the Pfizer/BioNTech vaccine and half to a placebo. Most of the 152 recruitment sites were in the United States (130), followed by Turkey (9), Germany (6), and South Africa (4). The study also followed 2,260 US children 12 to 15 years old, with half receiving the intervention and half receiving placebo.

VE was 91.1% up to 6 months after the second vaccine dose, regardless of previous COVID-19 infection (95% confidence interval [CI], 89.0 to 93.2). Against severe disease it was 97% (95% CI, 80.3% to 99.9%).

When the researchers looked at VE across age, sex, race, or COVID-19 risk factors, VE was always 86% or higher, although they note that youth data was not available for 6 months because of when enrollment began (Oct 15, 2020, vs Jul 27, 2020, for adults). VE peaked at 96.2% from 7 days to less than 2 months after the second dose, but at 4 months it declined to 83.7%, with an average decline of 6% every 2 months.

More vaccine recipients reported local and systemic events than placebo recipients, with mild-to-moderate injection site pain and fatigue being the most common, respectively. People who had COVID-19 prior to vaccination reported more systemic reactions after the first dose, whereas those who were naive to COVID-19 reported more systemic reactions after the second. While 15 vaccine recipients and 14 placebo recipients died, none of the deaths were considered related to the intervention.

Because reactogenicity events among participants not in the reactogenicity subset were reported as adverse events, the researchers say that the data show imbalances toward the Pfizer group (30% vs 14% for adverse events, 24% vs 6% for related adverse events, and 1.2% vs 0.7% for severe adverse events).

"Despite a gradually declining trend in vaccine efficacy, BNT162b2 had a favorable safety profile and was highly efficacious in preventing COVID-19," the researchers conclude.
Jul 28 medRxiv study

Treated MIS-C shows favorable follow-up at 6 months, study says

In a longitudinal cohort of 25 children with multisystem inflammatory syndrome in children (MIS-C), all were asymptomatic and at their functional baseline at 6-month follow-up, according to a Pediatrics study yesterday. The study included a total of 50 children, with some lost to follow-up, but during all intermediary follow-ups, symptoms were improving.

All study participants were admitted to Cohen Children's Medical Center with MIS-C from Apr 17 to Jun 20, 2020 (median age, 8.5 years; range, 9 months to 17 years). Most patients exhibited rapid clinical improvement, with an average hospital stay of 5 days. At discharge, 69% of 26 patients with left ventricular (LV) systolic dysfunction had resumed normal function, 15% had persistent but improved dysfunction, and 15% had mild dysfunction at admission but no available discharge data.

At 2 weeks, 47 presented for follow-up, and 47% said they got tired with ordinary activities, most of them (81.8%) having experienced shock or myocardial systolic dysfunction at initial admission. All other patients were asymptomatic. Platelet levels were elevated compared with admission (median, 463,000 cells per microliter vs 172,000), but all other markers had normalized. Some LV systolic (one patient) and diastolic (five) function persisted.

The follow-up at 8 weeks involved 42 people, with 5 (12%) continuing to experience fatigue during regular activity. All LV systolic function was normal, and any remaining coronary aneurysms and dilation had resolved. However, 4 (9%) still had diastolic dysfunction, and 5 (12%) had qualitative coronary abnormalities.

By 6 months, the 25 available patients were asymptomatic and at their functional baselines. Despite being asymptomatic, one patient still had LV diastolic dysfunction, but cardiac magnetic resonance imaging at 8 weeks didn't show inflammation or fibrosis.

"Early and mid-term prognosis after hospitalization and immunomodulation treatment for MIS-C is excellent with return to functional baseline, normalized LV systolic function, and resolved coronary abnormalities. However, persistence of diastolic dysfunction in a few patients confounds our understanding of MIS-C," write the researchers.
Jul 28 Pediatrics study

Liberia battles Lassa fever outbreak marked by high case-fatality rate

Liberia is battling a Lassa fever outbreak with 13 cases confirmed so far, 9 of them fatal, reflecting a higher case-fatality rate than the country has recorded over the past 5 years, the World Health Organization (WHO) African regional office said in its latest weekly outbreaks and health emergencies report.

The confirmed cases were reported from January through early July among patients from four counties in central Liberia: Bong, Grand Bassa, Montserrado, and Nimba. Females make up 54% of cases, and all but three of the cases are in people older than 16. Sixty contacts are currently being followed, and the response has been stepped up in the affected counties.

Lassa fever is endemic in Liberia and other West African countries. The viral hemorrhagic illness is similar to Ebola, but it usually less likely to be fatal, though it can cause severe disease. The virus is spread by rodents and jumps to humans through contact with rodent urine and droppings. It can spread among humans through contact with body fluids.
Jul 25 WHO African regional office weekly report

Prepackaged salad recall expands in 3-state Salmonella outbreak

Bright Farms yesterday expanded its recall of packaged salad greens that have been linked to a Salmonella outbreak that has now sickened 11 people in 3 states, according to federal health officials.

The recall involves products packaged at its Rochelle, Ill., facility and were sold in Illinois, Iowa, Indiana, and Michigan, the Food and Drug Administration (FDA) said in a recall update. In addition to several products that were subject to a Jul 15 recall, the expansion yesterday includes baby spinach that was sold in 4- and 8-ounce packages. The product is past its expiration date. The expiration date for the previously recalled products is today.

Also, the Centers for Disease Control and Prevention (CDC) in an outbreak update yesterday said it has received reports of three more cases and one more affected state since its Jul 15 update: Michigan. The states with earlier cases include Illinois and Wisconsin. Of the 11 patients reported so far, 2 have been hospitalized, and no deaths have been reported.

The outbreak subtype is Salmonella Typhimurium. An investigation at the farm found samples that were positive for Salmonella Liverpool, and health officials are using the PulseNet national subtyping network to see if there are any people infected with that strain.
Jul 28 FDA recall update
Jul 28 CDC outbreak update

Stewardship / Resistance Scan for Jul 29, 2021

News brief

OIE report shows countries using fewer antimicrobials in animals

A new report from the World Organisation for Animal Health (OIE) shows a global decline in the use of antimicrobials in animals.

Of the 69 countries that provided data for 2015 through 2017, an overall decrease of 34% was observed, with antimicrobial quantities dropping from 174.01 milligrams per kilogram (mg/kg) to 114.84 mg/kg. Among the 102 countries reporting data for 2017, the estimated amount of antimicrobials used in animals was 107.68 mg/kg.

"The decrease in antimicrobial quantities adjusted by animal biomass in all OIE Regions represents countries' commitment to the responsible use of antimicrobials in animals at the country level," the reported stated.

While the report is the fifth published by the OIE on antimicrobials intended for use in animals, it's the first to analyze trends among countries.

In addition, a record high 160 countries provided data for the report (a 23% increase in participation), and 133 countries reported more detailed quantitative data than in previous reports (a 16% increase). The report attributed that finding to countries continuing to develop their antimicrobial use monitoring systems.

Among other findings, 112 countries (70%) reported that they did not use any antimicrobial agents for growth promotion in animals, regardless of the presence or absence of national legislation. Twenty-three countries reported that a lack of regulatory framework, human resource constraints, and lack of information technology tools were barriers faced in reporting quantities of antimicrobials for use in animals.

Given these challenges, the OIE advises caution in interpreting the data.

"The OIE remains strongly committed to supporting its Members in developing robust and transparent measurement reporting mechanisms for antimicrobial use, but the challenges faced by many of our Members must not be under-estimated," the report said. "While data collection systems further develop, this annual report will provide an essential global and regional analysis of antibiotic use in animals, and changes over time."
Jul 27 OIE report

UK funds project to track resistant pathogens in food, agriculture

The UK government this week announced £19.2 million (US $26.8 million) in funding for a project that will use genomic technology to track foodborne and antibiotic-resistant pathogens through the food-production system.

The funding will help the Pathogen Surveillance in Agriculture, Food and the Environment (PATH-SAFE) program develop a pilot national surveillance network, using the latest DNA sequencing technology and environmental sampling, to improve detection and tracking of pathogens from farm to fork in all four nations of the United Kingdom, according to a press release from the UK's Food Standards Agency.

The focus of the project will be the creation of a database for storing, analyzing, and sharing sequence and source data collected from multiple locations.

"This project is designed to help safeguard UK food, agriculture and consumers by using cutting edge technology to understand how pathogens and AMR [antimicrobial resistance] spread," FSA Chief Scientific Officer Robin May, PhD, said. "Tracking the source of these issues will ultimately help us to develop better control strategies to reduce illness and deaths."
Jul 27 FSA press release