Moderna COVID-19 vaccine found to be non-inferior in adolescents
Moderna's COVID-19 vaccine was safe in adolescents 12 to 17 years old, with a similar immune response to that in young adults, according to results of an ongoing phase 2-3 trial published in the New England Journal of Medicine yesterday.
The researchers assigned 3,732 participants two doses of either the Moderna vaccine or a placebo in a 2:1 ratio from Dec 9, 2020, to Feb 28, 2021. The average age of the cohort was 14.3 years, 51% were male, and 84% were White. Participants were not excluded if they had experienced anaphylaxis or serious allergic reactions in the past, unless it was to a vaccine.
Geometric mean titer ratio of pseudovirus neutralizing antibody titers in the intervention arm compared with young adults was 1.08 (95% confidence interval [CI], 0.94 to 1.24). Serologic response was 98.8% in adolescents, only 0.2 percentage points lower than the 98.6% found in young adults (95% CI, -1.9 to 2.4).
The Moderna vaccine had an acceptable safety profile in adolescents, according to the researchers, but they did note that 6.8% to 8.9% of vaccine recipients had grade 3 local adverse reactions and 4.4% to 13.7% experienced grade 3 systemic adverse reactions. One person even had a grade 4 fever (< 0.1%). As of the report write-up, none had myocarditis or pericarditis, but the researchers say this is expected given the sample size.
No cases of COVID-19 occurred in the intervention group starting 14 days after the second dose, but four occurred in the placebo group. Because of the low cases in either group, the researchers write, "The efficacy analyses were secondary objectives of the trial because of milder Covid-19 disease and a lower disease incidence among adolescents than among adults in the phase 3 trial. However, the effectiveness of the mRNA-1273 vaccine in adolescents between the ages of 12 and 17 years is supported by both the noninferiority of the immunogenicity results for the vaccine and the preliminary estimate of vaccine efficacy."
Aug 11 N Engl J Med study
Clinical trial shows promise for monoclonal antibody malaria preventive
For the first time, researchers yesterday reported that a monoclonal antibody can prevent malaria in humans. A team based at the National Institute Allergy and Infectious Diseases (NIAID) Vaccine Research Centers published their phase 1 clinical trial results yesterday in the New England Journal of Medicine.
The monoclonal antibody, called CIS43LS, was developed from a neutralizing antibody isolated from the blood of a volunteer who had received an investigational malaria vaccine. Researchers examined whether the monoclonal antibody could safely prompt high-level protection against experimental exposure to infected mosquitoes.
For the phase 1 study, the team enrolled 40 healthy adults ages 18 to 50 who had never had malaria or been vaccinated against the disease. For the first half of the trial, 21 participants got one dose of the monoclonal antibody through intravenous infusion or subcutaneous injection. They followed the group for 6 months, looking at safety, tolerability, and durability of antibody levels.
The second part of the study involved controlled human exposure to the bites of Plasmodium falciparum-infected mosquitos 4 weeks after monoclonal antibody administration. It also evaluated a second IV infusion, included more participants who got a first infusion, and added a control group.
After 3 weeks, none of the patients in the treatment group developed malaria, but five of six in the control group did. Of the treatment group, two had received just one dose 9 months earlier, suggesting that one dose can prevent malaria 1 to 9 months after treatment.
A larger phase 2 trial is underway in Mali during the country's 6-month malaria season.
Robert Seder, MD, part of the study group, said in a National Institutes of Health press release that monoclonal antibodies may be a new approach for preventing malaria in military personnel, travelers, and health workers. "Further research will determine whether monoclonal antibodies can also be used for the seasonal control of malaria in Africa and ultimately for malaria-elimination campaigns."
Aug 11 N Engl J Med study
Aug 11 NIH press release
New Hampshire reports fatal Jamestown Canyon virus case
New Hampshire health officials recently reported the state's first Jamestown Canyon virus (JCV) case of the season, an adult who died from the infection.
The patient is from Dublin, located in the east central part of the state, the New Hampshire Department of Health and Human Services (NHDHHS) said in a statement. The patient was hospitalized with worsening neurological symptoms and died, with JCV as a contributing cause.
The city's risk level has been raised to high, and the risk level for surrounding cities (Harrisville, Peterborough, Jaffrey, and Marlborough) will increase to moderate. Officials warned that the risk will increase through the summer and into the fall and that residents and visitors should take steps to avoid mosquito bites. New Hampshire has now recorded 15 cases since 2013.
JCV usually circulates between mosquitoes and deer, but can also infect people. Reports in the United States have increased due to enhanced recognition and testing; the United States typically records about 15 cases each year. The virus mainly circulates in the Midwest and Northeast, typically in late spring through the middle of fall. Most infections are asymptomatic or mild, but severe cases can lead to encephalitis, meningitis, or death. There are no vaccines or treatments.
Aug 6 NHDHHS press release
H5N1 avian flu strikes poultry in Ivory Coast
Animal health officials in the Ivory Coast reported a highly pathogenic H5N1 avian influenza outbreak in poultry, the country's first since 2016, according to a notification from the World Organization for Animal Health (OIE).
The outbreak struck a large number of village birds—which included chickens, Guinea fowl, turkeys, ducks, and quail— in Mondoukou in Comoe district, located in the east central part of the country. The events spanned 39 farms. The virus killed 43,410 of 76,613 susceptible birds. Culling, disinfection, and establishing a surveillance zone are part of the response. So far, the source of the virus isn't known.
A few other African nations have reported recent H5N1 outbreak, including Togo, Mali, and South Africa.
Aug 10 OIE report on H5N1 in Ivory Coast