Moderna announces promising efficacy results from mRNA flu vaccine trial

News brief

Moderna today reported promising relative vaccine efficacy (rVE) findings from a phase 3 trial of its seasonal mRNA flu vaccine candidate compared to a standard-dose licensed flu vaccine in adults ages 50 years and older.

senior vaccination — *Zinkevych / iStock*

In a press release, the company said its candidate flu vaccine, called mRNA 1010, showed superior results, with an rVE of 26.6% in the overall study population (95% confidence interval, 16.7% to 35.4%).

Moderna also reported strong rVE against each of the three individual strains: H1N1 (29.6%), H3N2 (22.2%), and B/Victoria (29.1%). It added that subgroup analysis showed a consistently strong rVE point estimate across all age-groups, risk factors, and previous vaccination status. Also, the rVE in people ages 65 years and older was 27.4%.

Large trial spanned 11 countries.

The trial enrolled nearly 41,000 adults ages 50 and older across 11 countries. The company said that the new findings, which will be presented at an upcoming medical conference and submitted for peer-reviewed publication, follow earlier phase 3 trial findings that showed superior seroconversion rates and geometric mean titer ratios against all strains in the vaccine compared to high- and standard-dose seasonal flu vaccines.

Stephane Bancel, MBA, Moderna’s chief executive officer, said the strong phase 3 efficacy results are a significant milestone in the company’s effort to reduce the flu burden in older adults.

“The severity of this past flu season underscores the need for more effective vaccines," he said. "An mRNA-based flu vaccine has the potential advantage to more precisely match circulating strains, support rapid response in a future influenza pandemic, and pave the way for COVID-19 combination vaccines."

Kentucky, Utah report more measles cases

News brief

Stephanie Soucheray, MA

Over the weekend Kentucky reported three more measles cases, all from the same family in Woodford County. None of the individuals were vaccinated, health officials from the state said.

Kentucky now has six confirmed measles cases in 2025, following the identification of a measles infection in February in an adult state resident. Officials urged vaccination for all residents, especially school children, noting that, for the 2024-25 school year, only 86.9% of Kentucky kindergartners were fully vaccinated against measles.

In other US measles news, Utah has two new measles cases, raising the state total to seven. The two news cases are in unvaccinated people, and at least one of the newly identified infected residents has been linked to other infected people, according to a statement posted on X by the Utah Department of Health and Human Services.

Starting this week, the department will post full measles updates on Wednesdays.

Health officials encouraged by recent trends in Africa’s mpox outbreaks

News brief

Lisa Schnirring

African health officials are tracking an encouraging decline in some of the region’s most recent mpox hot spots, including Sierra Leone, which over the past few months has reported a surge that came with spread of the clade 2b virus to some West African nations.

At an Africa Centres for Disease Prevention and Control (Africa CDC) briefing on June 26, Yap Boum, PhD, MPH, deputy incident manager for Africa CDC's mpox response, said cases in Sierra Leone made up 41% of mpox cases in Africa the previous week, down from 63% a few weeks ago.

Though Boum urged caution in interpreting the trends, he said that countries are battling different viral clades, have implemented different measures, and are seeing different social behaviors in the highest-risk populations.

Sierra Leone is still averaging about 500 cases a week, and a high test-positivity rate (91%) suggests that more active surveillance efforts are needed. Boum said that Africa CDC will deploy 200 community health workers to help with active case detection and contact tracing.

A consistent downward trend has also been reported in two other epicenters, the Democratic Republic of the Congo (DRC) and Uganda. Boum said testing remains a challenge in the DRC, where 97.5% of cases are reported from six of the country’s provinces. Uganda’s cases were up a bit, but the area is stabilizing, with no new cases reported from Kampala over the past few weeks.

Watching a rise in Togo

Elsewhere, Togo has reported a steady rise in cases over the last 3 weeks that prompted the deployment of an Africa CDC incident-management support team to assist with surveillance, infection prevention and control, and lab capacity.

So far, seven African countries have launched vaccination campaigns, and nearly 700,000 people have been vaccinated so far. Uganda recently received an allocation of nearly 98,000 more doses. Sierra Leone started its second round of vaccination on June 23, focusing on contacts and high-risk groups in hot spots that span the country’s 16 districts.

However, the region is still far short of its goal for mpox vaccine. In April, officials projected the region would need 6.4 million doses over the next 6 months.