Mary Allen Staat
The NIH’s National Institute of Allergy and Infectious Diseases awarded $30 million to Cincinnati Children’s Hospital to research children’s first exposures to influenza and how their immune system reacts to infection in the future.
According to the hospital, the findings could help guide the development of a universal influenza vaccine by providing a better understanding of the ideal strains to include in it.
Mary Allen Staat, MD, MPH, principal investigator for the new grant, noted that influenza vaccines cannot be used in children aged younger than 6 months and do not have long durability. A universal influenza vaccine, on the other hand, could offer protection for people of all ages, have a duration of at least 1 year and achieve more than 75% efficacy.
“The difficulty in creating a universal vaccine is that we don’t have a clear understanding of the immunology of influenza infection and what the correlates of protection are,” Staat told Infectious Diseases in Children. “In addition, the epitopes of influenza infection rapidly change and thus, the antigens used in vaccines may not match what is circulating and then will not provide the level of protection that is needed.”
She said maternal immunity may offer some protection for infants who cannot be immunized, but the level of protection may not be sufficient or timed in a way that will protect the infant during the influenza season.
Congress has dedicated $140 million for fiscal year 2019 for universal influenza vaccine research. The $30 million given to Cincinnati Children’s Hospital will be used to support the IMPRINT cohort study, which will include more than 2,000 sets of mothers and infants from Cincinnati and Mexico City. Staat said Mexico City was chosen as a second site because they had success with mother-infant cohort studies, a national influenza immunization program and an influenza surveillance program. The mother-child pairs in both sites will receive weekly medical testing for at least 3 years. Researchers will explore how a person’s first influenza exposure — whether it is from a circulating strain or a vaccine — will affect their immune response during future influenza exposures. Staat said this imprinting could help explain the vaccine’s varying efficacy in recent years — ranging from 60% down to 20%.
“We hope to better understand what the immunological responses to an initial influenza virus exposure in infants is in the context of infection compared to vaccination and then to determine the impact of this first exposure to the susceptibility and immunological responses to a second infection and/or vaccination,” Staat said. “It is likely that these initial immunologic responses initiated during infancy affect all subsequent responses to influenza exposures. The ultimate goal is to understand these responses so a more effective universal influenza vaccine can be developed.”
Early estimates for the 2018-2019 influenza season demonstrated a 47% overall efficacy, with “limited to no” protection for older adults, according to the CDC. The agency estimated that up to 59,600 people died in the 2018-2019 season, and influenza-related complications persist as a top 10 cause of death. – by Katherine Bortz
CDC. Mortality in the United States, 2017. https://www.cdc.gov/nchs/products/databriefs/db328.htm. Accessed May 6, 2019.
CDC. Influenza (Flu). https://www.cdc.gov/flu/index.htm. Accessed May 6, 2019.
Disclosure: Staat reports no relevant financial disclosures.