A universal flu vaccine is high on the wishlists of most immunologists, virologists — and even funding agencies. This week US National Institutes of Health director Francis Collins told USAToday that he’s “guardedly optimistic” that such a long-term shot will be developed within the next five years. That timeline could be aided by a report out today in Science that a single antibody is capable of inactivating all subtypes of influenza A.

A team led by Antonio Lanzavecchia, an immunologist at the Institute for Research in Biomedicine in Bellinzona, Switzerland, screened blood plasma from eight donors known to produce antibodies against multiple flu subtypes from a vaccination. One of these donors had H1N1 swine flu in 2009 and was vaccinated for seasonal flu in 2010 — and, in his plasma, the researchers discovered an antibody that appeared to target all 16 subtypes of influenza A. In animal studies, the antibody also protected mice from H1N1 swine flu and ferrets from H5N1 bird flu.

“This is a landmark study because the authors identified a single antibody that is capable of stopping virtually all different types of flu viruses,” immunologist Scott Hensley of Philadelphia’s Wistar Insitute told Nature Medicine.

Unlike <a href=“https://www.nature.com/nm/journal/v16/n12/full/nm1210-1347.html”’>previous approaches to developing a universal vaccine, which typically target proteins conserved across only a handful of the influenza A subtypes, this antibody binds to a region that “just can’t tolerate mutations,” Hensley says. Although other groups’ attempts to target this conserved region failed, this antibody works, preventing the virus from merging with the cell’s membrane to halt the infection’s spread.

It’s a major discovery — but don’t expect a universal vaccine tomorrow. The researchers still need to tailor an antigen that matches the antibody, develop a delivery system, and test it in humans. But this antibody does make Collins’s five-year timeline for a universal flu vaccine seem a bit more realistic.

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People infected with the swine flu virus developed antibodies that could hold the secret to developing a universal flu vaccine, according to a study published this week in the Journal of Experimental Medicine.

In last month’s issue of Nature Medicine, I wrote about a number of different strategies in the works to develop a long-acting vaccine aimed at providing broad-acting protection against all sorts of influenza viral strains. Most of these approaches involve developing antibodies or T cell responses to conserved proteins in the virus that don’t change a great deal from one strain to the next.

Keeping in line with this tactic, a team led by Patrick Wilson, an immunologist at the University of Chicago, inspected the antibody response induced by people who fell ill with the 2009 H1N1 pandemic. They found close to a hundred antibodies that reacted with the virus, including five that were cross-reactive against many strains, including the 1918 H1N1 Spanish flu and H5N1 avian flu viruses.

Several of the antibodies acted against the conserved stalk of the ‘H’ protein called hemagglutinin, and some of them were actually the same as those found by previous groups mentioned in our news story.

The study authors now hope to use the antibodies to develop a long-lasting flu jab. “It says that a universal influenza vaccine is really possible,” Wilson told Reuters.

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Summer’s still in full swing, but the US Food and Drug Administration (FDA) is already thinking about flu season. The regulatory agency just announced that it has approved the flu vaccine for 2010-2011, and it includes protection against the 2009 pandemic H1N1 ‘swine flu’ strain as well as regular seasonal influenza.

Nearly 20% of the population in the US suffers some form of influenza each year, leading to more than 200,000 hospitalizations and 36,000 deaths, according to estimates from the US Centers for Disease Control (CDC).

This year’s crop of flu vaccines includes: Afluria by CSL Limited; Agriflu and Fluvirin from Novartis; GlaxoSmithKline’s Fluarix; FluLaval, manufactured by the ID Biomedical Corporation; FluMist, from MedImmune; and Fluzone and Fluzone High-Dose from Sanofi-Pasteur. The vaccines contain two strains of influenza A virus&mdash H3N2 and the “swine flu” strain of H1N1&mdash as well as influenza B virus.

For this flu season, the FDA recommends that all people six months or older get vaccinated. Previous guidelines focused on vaccinating the subset of the population most at risk for serious complications resulting from influenza: children, the elderly, people with existing health issues and those likely to come into contact with these high-risk groups.

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With many flu strains developing resistance to traditional small molecule treatments like Tamiflu and Rimantadine, antibodies could represent a new strategy in the war on influenza. The use of antibodies in treatment has thus far been limited by their cost, since culturing cells is a much more involved process than synthesizing compounds. But their ability to act on multiple strains lends hope for a universal treatment.

In a paper published in PLoS Pathogens, researchers from Sea Lane Biotechnologies, in collaboration with other institutions, relate their latest success with a particular antibody named A06. In both mouse models and cell cultures, this antibody was able to effectively treat the recent pandemic ‘swine flu’ strain of H1N1. A06, which was previously shown to be successful against both H5N1 (avian flu) and seasonal H1N1, was isolated from a library of antibodies culled from the survivors of a 2006 epidemic of especially virulent bird flu in Turkey.

“These antibodies came from the battlefield, so to speak,” says Richard Lerner, president of the Scripps Research Institute, one of the authors of the PLoS paper.

A06 binds to the stem portion of hemaggluttinin, a surface protein on the influenza virus. Normally, when influenza infects a host cell, its stem springs open, revealing a fusion peptide which it uses to bind to the cell. The antibody blocks that ability to bind, rendering the virus unable to infect host cells. Most other antibodies target the prominent globular head of hemaggluttinin, but Lerner says that targeting the stem means it’s harder for the virus to develop resistance. Influenza can easily change the structure of the protein loops on the head of the protein (for example, a single amino acid substitution can result in Tamiflu resistance in seasonal H1N1), but the stem, being much more essential, proves more difficult for the virus to change significantly without damaging reproductive function.

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There was a sense of relief yesterday at a New York Academy of Sciences conference on H1N1. Nearly a year before, many of the same people had gathered to discuss the emerging swine flu pandemic; this year, they’re catching their breath. The speakers, however, didn’t mince their words when it came to the need to bolster pandemic preparedness.

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Swine flu seems to be ebbing in much of the Northern Hemisphere, according to the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC). But health officials maintain that the pandemic is far from over, and they are continuing to urge people to get vaccinated.

In the US, health experts convened a press conference before the holidays at the National Press Building in Washington, DC, warning that the virus could resurge and that there’s still plenty of swine flu going around. According to the latest CDC report, ending the week of December 19, only seven states still suffer from widespread influenza, compared to the outbreaks that hit most of the country earlier in the fall.

At the press conference FDA head Margaret Hamburg defended the decision not to use adjuvants, which could have meant more vaccine delivered sooner. She said that regulatory agencies were not prepared to go outside of the regular review process to approve them on an emergency basis given that the vaccine worked fine without the additive. She also cited potential safety concerns and a public that remains jittery about vaccines in general.

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As countries around the world continue to stockpile Roche’s widely used Tamiflu, the effectiveness of the anti-flu drug is being called into question.

A review of past clinical trials out today found no clear evidence that the antiviral med can protect against flu-related complications, such as pneumonia, among otherwise-healthy adults. The BMJ report concluded that Tamiflu, also known by its generic name oseltamivir, reduces the duration of symptoms by 24 hours among otherwise-healthy individuals, but does not cut the risk of complications.

A piece in The Atlantic last month also raised red flags about Tamiflu’s effectiveness and side effects. Some studies have suggested that the antiviral induces nausea and vomiting among about 20% of adults and causes adverse psychiatric symptoms among about 20% of children — although Roche, which markets the drug, says there is no causal link. In Japan, where Tamiflu is frequently prescribed, the drug is also potentially linked to 50 deaths from cardiac arrest between 2001 and 2007, according to the head of medicines watchdog quoted in The Atlantic.

With Tamiflu-resistant swine flu strains on the rise, we may need a replacement. Researchers at the University of California, San Diego, modeled the binding between FDA-approved drugs and proteins on the outside of the flu virus. Their computer program identified 15 compounds, all with a greater affinity than any existing anti-flu meds, including Tamiflu. Six of these drugs are already being tested against H1N1, they reported Sunday at the American Society for Cell Biology meeting in San Diego.

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