Novavax applies for COVID booster EUA as UK approves 2-strain booster
Following the Food and Drug Administration (FDA) emergency use authorization (EUA) of the Novavax COVID-19 vaccine last month for the primary vaccine series, the company announced today that it has applied for an EUA for the vaccine to also be used as a booster in adults ages 18 and older.
In an announcement today, Novavax said if authorized, the vaccine would be the first protein-based COVID-19 booster for adults. It said its application covers both heterologous (different-brand) and homologous (same-brand) booster strategies.
Stanley Erck, Novavax's president and chief executive officer, said, "It's important for people to have a choice as they evaluate how to stay protected against COVID-19, and boosters are an invaluable tool to build upon immunity obtained from previous vaccinations."
A phase 3 study found that the third dose produced robust antibody responses that met or exceeded levels seen in the primary series. The vaccine also prompted a significant antibody response when used as a heterologous booster.
Local and systemic responses lasted about 2 days and showed an increasing incidence across all three doses. Rare instances of myocarditis, pericarditis, and anaphylaxis have been reported outside of clinical trials, and, earlier this month, the European Medicines Agency recommended that the vaccine maker carry a warning about the two heart conditions.
Aug 15 Novavax press release
In other vaccine developments, the UK Medicines and Healthcare Products Regulatory Agency today approved Moderna's bivalent (two-strain) booster shot, which covers the original SARS-CoV-2 virus plus the Omicron BA.1 variant. The group said it based its findings on clinical trials that showed the booster prompted a strong immune response against BA.1 and the original virus and a good response against Omicron BA.4 and BA.5 subvariants.
The United Kingdom is the first to approve a bivalent booster vaccine. Companies that make mRNA vaccines are working on bivalent booster shots for the US market that target BA.4 and BA.5.
Aug 15 MHRA statement
Easing rules for gatherings, vaccine proof tied to Omicron spike in Korea
Dialing back rules for social gatherings and COVID-19 vaccine passes in South Korea was tied to a record spike in SARS-CoV-2 Omicron variant infections in March 2022, according to an observational study published late last week in JAMA Network Open.
Researchers in South Korea mined daily data on COVID-19 cases and the proportion of Omicron infections from Dec 1, 2021, to Mar 16, 2022. They multiplied the number of daily cases by the rate of positive Omicron tests to arrive at a proxy of variant activity in the community.
In mid-January 2022, the country relaxed restrictions on social gatherings, stopped requiring proof of COVID-19 vaccination in public facilities, expanded community screening, and mandated screening for all schoolchildren.
The Rt, or the average number of cases resulting from a single infected person, was greater than 1 throughout the study period, indicating uncontrolled viral transmission. The easing of limits on social gatherings was linked to an increase in Rt of 20.4% (95% confidence interval [CI], 5.8% to 36.5%), and suspension of COVID-19 vaccine passes was tied to a jump in Rt of 10.9% (95% CI, 3.2% to 24.8%).
The use of community COVID-19 screening centers and mandatory screening in schools, however, was associated with declines in Rt of 16.8% (95% CI, -25.2% to -11.1%) and 18.8% (95% CI, -22.2% to -11.1%), respectively.
The study authors noted that South Korea had successfully controlled SARS-CoV-2 transmission through the use of public health and social measures (PHSMs) without lockdowns in 2020 and 2021, but the world-record spike of 600,000 new daily Omicron cases occurred soon after these measures were relaxed.
The screening protocols appeared to help slow the spread of the virus, they said, but "our finding of a mean Rt greater than 1 during the study period suggested there may have been difficulty in controlling the COVID-19 pandemic in South Korea. The findings suggest awareness of Rt can inform policy planning and practice, including by allowing timely implementation and relaxation of PHSMs."
Aug 12 JAMA Netw Open research letter
FDA green-lights baloxavir use for flu in kids as young as 5
Roche recently announced that the FDA has approved the use of baloxavir marboxil (Xofluza) for treating flu in children ages 5 to 12. Also, the FDA approved the drug for postexposure prophylaxis (prevention) in kids ages 5 to 12 who had contact with someone with flu.
Baloxavir marboxil was first approved for use as a single-dose treatment for uncomplicated flu for people ages 12 and older in 2018, the first new antiviral to be approved by the FDA in two decades. Two years later the FDA approved the use of the drug for postexposure prophylaxis.
Levi Garraway, MD, PhD, Roche's chief medical officer and head global product development, said that, despite the ongoing COVID-19 pandemic, flu is still a public health threat, and effective flu antivirals are a critical tool for easing the burden on healthcare systems.
Aug 12 Roche press release
Salmonella linked to backyard poultry sickens 312 more people
In its latest update on a Salmonella outbreak linked to backyard poultry, the Centers for Disease Control and Prevention (CDC) reported 312 more cases, raising the nation's total to 884 in 48 states.
The CDC also said one illness has now been reported in the District of Columbia. The five states with the most cases are California (59), Minnesota (46), Texas (45), Wisconsin (41), and Missouri (36).
Two more Salmonella subtypes—I 4,,12:i:- and Indiana—were added to the outbreak, bringing the total to seven. The previously announced strains are Enteritidis, Hadar, Infantis, Mbandaka, and Typhimurium.
Patient ages range from 1 to 102, and 55% are female. The latest illness onset was Jul 23. Of cases with available outcome data, 158 people were hospitalized. The number of deaths held steady at 2.
People bought poultry from 177 retail locations across 41 states. Some bought poultry from more than one location. Testing by health officials in four states have identified the outbreak strains in poultry and poultry environments, people's homes, and stores. They are New Mexico, North Dakota, Tennessee, and Wisconsin.
Whole-genome sequencing of 904 samples from sick people, animals, and the environment to identify risk of antibiotic resistance found that 40.6% were resistant to 13 key antibiotics. Though most people with Salmonella infections recover without antibiotics, the CDC said some illnesses would be difficult to treat with recommended drugs and would require a different antibiotic choice.
Aug 12 CDC Salmonella outbreak update