Novel Indicator of Influenza Immunity Identified
Individuals with higher levels of hemagglutinin (HA) stem antibodies may be better protected against influenza virus infection, results of a new study demonstrate. And according to the study authors, the results can aid in the development of novel vaccine candidates that target the HA stem.1
To analyze influenza virus transmission, the researchers studied 88 participants with pandemic H1N1 influenza A virus infection in Nicaragua along with 300 of their household contacts.2
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The researchers measured the household contacts’ pre-existing HA stem antibody levels and also gathered blood samples 30 to 45 days later. To determine whether these 300 participants had become infected with influenza virus, researchers also collected participants’ nasal and throat swabs at baseline and then every few days for approximately 2 weeks thereafter.
Of all the household contacts, 84 had contracted laboratory-confirmed influenza virus infection; 53 of those infected had developed influenza symptoms.
The researchers determined that participants who had higher levels of HA stem antibodies at baseline were less likely to become infected with influenza. In turn, the level of HA stem antibodies may be able to be used as a correlate of protection against influenza virus infection.
According to the researchers, the results can also aid in the development of novel vaccine candidates that target the HA stem, which could provide wider-reaching and stronger protection against influenza than vaccines that are currently available.
—Colleen Murphy
References:
1. Ng S, Nachbagauer R, Balmaseda A, et al. Novel correlates of protection against pandemic H1N1 influenza A virus infection [published online June 3, 2019]. Nat Med. doi:10.1038/s41591-019-0463-x.
2. NIH-supported study reveals a novel indicator of influenza immunity [press release]. Bethesda, MD: National Institute of Allergy and Infectious Diseases (NIAID); June 3, 2019. https://www.nih.gov/news-events/news-releases/nih-supported-study-reveals-novel-indicator-influenza-immunity. Accessed June 4, 2019.