COVID-19 Scan for Oct 31, 2022

News brief

First-dose COVID vaccine coverage was higher in states with mandates

First-dose COVID-19 vaccine uptake was higher in US states with worker vaccine mandates, suggesting that the requirements may have motivated even residents not covered to comply, concludes a study published late last week in JAMA Health Forum.

Centers for Disease Control and Prevention (CDC) researchers compared first-dose COVID-19 vaccine coverage in 12 states and Washington, DC, with vaccine mandates and no test-out option with that in 14 states that didn't require them or that offered a test-out option. The study period included the 8 weeks before and after the mandates were announced from Jul 26 to Dec 31, 2021.

An estimated 11.5% of 5,508,539 first-dose vaccine administrations were tied to the announcements. Vaccine receipt began to rise in the 13 jurisdictions with mandates 3 weeks after the announcement, with statistically significant increases of 0.20, 0.33, 0.39, 0.45, 0.49, and 0.59 percentage points in weeks 3 through 8, respectively, over the 62.9% coverage in the 14 comparison states.

While increases in vaccine primary series completion occurred 5 to 8 weeks post-announcement, a statistically significant difference of 56.3% between states with and without mandates was noted only at 7 and 8 weeks (difference, 0.2 percentage points).

The study authors noted that some states began mandating that certain groups of workers be vaccinated after the US Department of Justice's Office of Legal Counsel said on July 26, 2021, that public and private employers could require vaccination.

By Dec 31, 2021, 24 jurisdictions had mandated that at least one group of workers (eg, healthcare, long-term care, education, congregate care, the government) get vaccinated. By February 2022, the Supreme Court had declined to hear at least three challenges to the mandates, effectively leaving them in place.

The findings "suggest that the announcement of state-issued vaccine mandates may be associated with short-term increases in vaccine uptake," the researchers wrote. "This observed association may be a product of both a direct outcome experienced by groups governed by the mandate as well as the spillover outcome due to a government signaling the importance of vaccination to the general population of the state."
Oct 28 JAMA Health Forum study

Study shows more vaccine side effects following COVID-19 infection

A new large Canadian study finds that adults with previous moderate or severe COVID-19 infections were more likely to have an adverse event sufficient to limit routine activities or require medical assessment in the week following each COVID vaccine dose. The study was published today in Clinical Infectious Diseases.

The study was based on 684,998 vaccinated Canadian adults who received COVID-19 immunizations from Dec 22, 2020, to Nov 27, 2021. Participants were sent an electronic questionnaire 7 days after dose 1, dose 2, and dose 3 vaccination asking for details about previous COVID-19 infections and reactions to their immunization.

Among vaccinated people, 2.6% reported a COVID-19 infection in the 4 month prior to receiving an initial vaccine dose. Those with moderate (bedridden) to severe (hospitalized) COVID-19 infections were more likely to have a vaccine reaction preventing daily activities, at an adjusted odds ratio of 3.96 (95% confidence interval [CI]. 3.67 to 4.28) for the Pfizer-BioNTech vaccine; 5.01 (95% CI, 4.57 to 5.50) for Moderna, and 1.84 (95% CI, 1.54 to 2.20) for Oxford/AstraZeneca compared to no infection.

More adverse events were reported among those with moderate to severe COVID-19 infection following doses 2 and 3, but they were fewer than after dose 1. For participants who reported an asymptomatic or mild infection, there was no association with adverse vaccine side effects.

"The potential signal identified by our study requires further investigation via data linkage or other observational methods that do not rely on self-report," the authors concluded. "Providers should consider additional vaccine counseling on expected adverse effects for SARS-CoV-2 previously infected individuals prior to vaccination."
Oct 31 Clin Infect Dis study

News Scan for Oct 31, 2022

News brief

Report highlights animal transport as risk for spread of resistant bacteria

A report last week from the European Food Safety Authority (EFSA) suggests steps could be taken to limit the spread of antimicrobial resistance (AMR) in food-producing animals during transportation.

Using information from international reports, scientific literature, European legislation, and expert knowledge, scientists with EFSA's Panel on Biological Hazards set out to assess the most significant risk factors associated with the spread of antimicrobial-resistant bacteria and antimicrobial-resistance genes (ARB/ARGs) among poultry, pigs, and cattle when transported from the farm to the slaughterhouse. The panel was also asked to identify preventive measures and control options that could be implemented to reduce the spread of ARB/ARGs between food-producing animals during short and long journeys, and to identify data gaps.

The assessment identified the status that resistance (the presence of ARB/ARGs) of animals pre-transport as one of the main risk factors that almost certainly contributes to the probability of ARB/ARG transmission during transport, followed by increased fecal shedding, insufficient hygiene of vehicles and equipment, exposure to other animals carrying ARB/ARGs, and duration of transport. Among the factors that likely contribute to ARB/ARG spread were airborne transmission within the vehicle, health status of the animal, and high temperature and humidity.

To reduce the probability of ARB/ARG transmission in animals during transport, the report recommended minimizing the duration of transport, properly cleaning and disinfecting vehicles, organizing transport in relation to AMR criteria, improving biosecurity and animal husbandry and handling practices prior to and during transport, and segregating animals.

While a range of data gaps were identified, the panel said that quantifying the impact of transport on AMR transmission, compared with other stages of the food-production chain, was among the most urgent research needs.

"By identifying the main risk factors, mitigation measures and research needs in relation to the transport of animals, EFSA's assessment marks another step forward in the fight against antimicrobial resistance, based on the principle of 'One Health,' which integrates animal and human risk assessment," Frank Verdonck, Head of EFSA's Biological Hazards & Animal Health and Welfare Unit, said in an EFSA press release.
Oct 25 EFSA report
Oct 25 EFSA press release

Avian flu strikes poultry in US, Mexico

Three states reported more highly pathogenic avian flu outbreaks in poultry, including Minnesota, where the virus struck two commercial turkey farms, according to the latest updates from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).

One of the Minnesota outbreaks occurred at a turkey farm in Le Sueur County in the southern part of the state that houses 20,100 birds. The other struck turkeys at a farm in Stearns County in central Minnesota that, according to the Minnesota Board of Animal Health, has 75,000 birds.

Elsewhere, Colorado and Florida reported more outbreaks involving backyard birds.

So far, the Eurasian H5N1 outbreaks have led to the loss of nearly 47.8 million birds in 43 states.
USDA APHIS poultry avian flu updates
MBAH avian flu updates

In international developments, Mexico reported a highly pathogenic H5N1 avian flu outbreak at a commercial poultry farm Nuevo Leon state, near the border with Texas. The country had recently reported its first H5 detection in a wild bird.

According to the country's agricultural service, SENASICA, the virus struck a layer farm in Montemorelos that houses 60,000 birds. Officials said migratory birds from the United States and Canada are triggering the outbreaks, with additional detections found in wild birds in Tijuana and a family-owned layer farm in Juarez.
Oct 30 SENASICA report