Scientists have found a way to induce antibodies to fight a range of influenza subtypes, which may eventually eliminate the need for repeated seasonal flu shots. The study, which was conducted by scientists at The Scripps Research Institute (TSRI) and the Janssen Pharmaceutical Companies of Johnson & Johnson (Janssen), was part of TSRI’s long-term collaboration to strengthen research against infectious disease with the former Crucell Vaccine Institute.

Ian Wilson, PhD, of TSRI, says, “This study shows that we’re moving in the right direction for a universal flu vaccine.” A TSRI news release notes that several studies in the last decade have shown that some individuals are capable of making powerful antibodies that can fight many subtypes of influenza by targeting a site on the influenza virus that does not mutate rapidly. As such, the researchers tried to create an influenza vaccine specially designed to elicit them.

The scientists focused on hemagglutinin (HA), which is a protein on the surface of influenza present on all subtypes of influenza. The protein also provides the key machinery that enables the virus to enter cells. In order to create antibodies against the HA stem, the researchers looked to influenza’s own structure, specifically the universal recognition site of the broadly protective antibody CR9114 in the HA stem, as noted on the TSRI news release.

The vaccine candidate was designed, produced, and tested by a team of scientists, and the effort represents the first time scientists have been able to cut off the variable head region of HA. The features designed were able to stabilize the conformation of the original protein and mimic the key neutralizing site. The end goal was to use this synthetic version of the HA stem in a vaccine to teach the body to produce potent antibodies against the influenza virus and priming it to fight off a variety of strains.

The response of rodent and nonhuman primate models was studied, and the researchers found that animals given one stable immunogen produced antibodies that could bind with HAs in many influenza subtypes. Wilson states, “This was the proof of principle. These tests showed that antibodies elicited against one influenza subtype could protect against a different subtype.”

According to Wilson, the next step in the research is to see if the immunogen can do the same in humans. Wilson adds, “While there is more work to be done, the ultimate goal, of course, would be to create a life-long vaccine.”

Source: The Scripps Research Institute