News Scan for Jun 27, 2022

News brief

FDA to review Emergent's adjuvanted anthrax vaccine for adults

Emergent BioSolutions said in a news release late last week that the US Food and Drug Administration (FDA) has accepted for review an adjuvanted version of its anthrax vaccine for post-exposure prophylaxis (prevention) of anthrax.

The product, called AV7909—or Anthrax Vaccine Adsorbed, Adjuvanted—is designed to prevent disease caused by exposure to Bacillus anthracis, the bacterium that causes anthrax, in adults 18 to 65 years old. An adjuvant is a substance in a vaccine that boosts the body's immune response, and the US government stockpiles anthrax vaccine in the event of a bioterrorism event. The FDA will review Emergent's Biologics License Application (BLA) in the coming months.

Kelly Warfield, PhD, senior vice president of research and development at Emergent, said, "As we progress toward licensure of AV7909, which is designed to follow a two-dose immunization schedule and to elicit a faster immune response, we redouble our efforts to support the government's overall preparedness and response strategy for large-scale emergencies involving anthrax and other threats to public health."

The BLA submission, completed in April 2022, includes data from a phase 3 clinical study of AV7909 that evaluated vaccine lot consistency, immunogenicity, and safety following two shots in healthy adults. It also included data from a phase 2 study that evaluated non-interference between AV7909 and antibiotics approved for post-exposure prophylaxis of anthrax.

Advanced development and delivery of AV7909 is funded by the Biomedical Advanced Research and Development Authority (BARDA), within the Office of the Assistant Secretary for Preparedness and Response in the Department of Health and Human Services. Three years ago BARDA bought 50 million doses of AV7909 for the Strategic National Stockpile.
Jun 24 Emergent BioSolutions news release
Jul 3, 2019, CIDRAP News scan

H5N6 avian flu hospitalizes another person in China

China has reported another H5N6 avian flu infection in a human, this time involving a 58-year-old man from the Jiangxi province city of Ganzhou, home to more than 2.5 million people.

In a statement today, Hong Kong's Centre for Health Protection (CHP) said the man had been exposed to market poultry and is hospitalized in critical condition. Jiangxi province is in southeastern China.

The infection marks the country's 15th case of the year and its 79th since the virus was first detected in people in 2014. H5N6 cases are often severe or fatal in humans. The virus is known to circulate in poultry in a handful of Asian countries, but so far, China and Laos are the only nations to report illnesses in people.
Jun 27 CHP statement

More avian flu in US poultry and wild birds

Though the pace of highly pathogenic avian flu outbreaks in poultry has slowed in the United States, federal officials continue to report sporadic events, including five involving backyard birds, all in Washington state.

According to the latest update from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS), the virus hit five flocks in four counties: Pierce, King, Snohomish, and Yakima. Flocks ranged in size from 3 to 200 birds.

US outbreaks in poultry began in February, spreading roughly from east to west, with commercial poultry in the Midwest experiencing the biggest impact. So far, the outbreaks have led to the loss of more than 40 million birds across 36 states.

In related developments, APHIS reported 24 more H5N1 avian flu detections in wild birds, raising the national total since January to 1,635. Most were from Minnesota and Wisconsin, though Pennsylvania and Oregon also reported detections. Most of the new detections, which involved birds found dead, were in waterfowl such as pelicans, gulls, and terns.
USDA APHIS poultry avian flu updates
USDA APHIS wild bird avian flu updates

COVID-19 Scan for Jun 27, 2022

News brief

People with Down syndrome at higher risk for severe COVID-19

The Journal of Infectious Diseases has published studies demonstrating lower COVID-19 incidence—but a higher risk of severe disease—in people with Down syndrome (DS), and a lower COVID vaccine immune response.

In the first matched cohort study, based on data collected from the Kaiser Permanente system in California, 2,541 people with DS and 10,164 without DS were matched by age, sex, and race/ethnicity. The study was conducted from Mar 1, 2020, to Dec 31, 2020, before COVID-19 vaccines were available and before SARS-CoV-2 variants were widely circulating.

People with DS were 32% less likely to contract COVID-19 than non-DS matches (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], 0.56 to 0.83,) but they had severe COVID-19 six times more often (aHR, 6.14; 95% CI; 1.87 to 20.16).

The authors said caregivers of those with DS likely practiced stricter COVID-19 precautions than others, accounting for the lower overall infection rates, but anatomical changes seen in people with DS—including to the cardiovascular system—may explain why the disease is more severe in that group.
Jun 24 J Infect Dis severity study

In the second study, vaccine antibody levels in Dutch DS patients were compared to matched non-DS peers. Blood samples were collected at baseline, within 28 days of first vaccination dose, and 28 days after the second vaccine dose for 318 participants, 214 of whom had DS.

The authors said the DS population produced fewer antibodies than the non-DS group, and antibody levels were negatively correlated with age in the DS group, with those over 40 showing lower antibody levels than younger adults with DS. The same drop was not seen in non-DS adults over the age of 40.

"Antibody responses after SARS-CoV-2 vaccination in adults with DS are significantly decreased compared with healthy adults. In older adults with DS the decreased antibody responses were even more pronounced, which, combined with the highest mortality rates, makes this group particularly vulnerable," the authors concluded.

"A third or early booster vaccination should be considered in all adults with DS, given their risk for severe disease after SARS-CoV-2 infection."
Jun 24 J Infect Dis vaccine study

Pfizer releases promising findings on Omicron boosters

Ahead of a Food and Drug Administration (FDA) vaccine advisory committee meeting tomorrow to discuss updated COVID-19 vaccines, Pfizer and BioNTech released promising findings on two of their booster candidates targeting the Omicron SARS-CoV-2 variant.

The vaccine candidates that include an Omicron-adapted monovalent (single-strain) vaccine given as a fourth booster dose at 30-microgram and 60-microgram doses increased neutralizing geometric titers against BA.1 13.5-fold and 19.6-fold, respectively. The bivalent (two-strain) vaccine showed an increase of 9.1-fold and 10.9-fold increase, respectively. Early lab studies showed both vaccines neutralized BA.4 and BA.5 subvariants, but lesser than for BA.1.

The proportions of BA.4 and BA.5 are increasing in the United States, with the 7-day average for new daily cases is up 9% from a week ago. Meanwhile, the Centers for Disease Control and Prevention (CDC) said on Jun 24 that 58% of the US population lives in an area with medium or high community transmission, down a bit from 61% the week before.

In international developments, the UK Health Security Agency (HAS) said on Jun 24 that BA.4 and BA.5 subvariants are now dominant in Britain, with BA.5 growing the fastest and expected to become dominant. The HSA urged people to make sure their vaccine status is up to date. Elsewhere, Pakistan is now requiring masks for domestic air travel, given a steady rise in COVID-19 cases.
Jun 25 Pfizer-BioNTech press release
FDA Vaccines and Related Biological Products Advisory Committee meeting materials
Washington Post COVID-19 tracker
Jun 24 CDC tweet
Jun 24 UK HSA update
Jun 27 Reuters story