This episode is sponsored by Awesome Socks  Club, a sock subscription for charity.

Today is the FINAL day to sign up,   so click the link in the description  now to get lots of cool socks in 2021. [♪ INTRO]. There’s a lot of talk about  viruses and vaccines these days,   but COVID-19 isn’t the only  thing in need of a breakthrough.  New research published in Nature  Medicine brings us one step closer   to one of the holy grails of medicine:  a universal vaccine for the flu.

Seasonal influenza causes hundreds  of thousands of deaths every year,   and occasional flu pandemics can be much worse. And unlike many diseases where  one vaccine does the trick,   the flu forces us to keep  producing new vaccines every year. That’s because there are many variants of the flu  virus, and even those are constantly changing.

A vaccine’s job is to teach your immune system  to recognize an infectious agent, like a virus,   and respond to it when it enters your body.  There are a few ways to do this,   like with an intact but weakened form of  the virus, or just a small piece of it. Once your immune system has fought off the decoy,   it’s primed to do so again more quickly and  effectively when the real infection comes along. Flu vaccines are often designed to target a  protein called hemagglutinin, or HA for short.   This is a structure on the virus that  lets it attach to cells during infection.

HA is shaped sort of like a skinny  mushroom, with a head and stalk.   That head is the easiest  part for antibodies to reach,   so our immune systems tend to target it, and  our vaccines are designed to do so as well. But as new flu strains and subtypes evolve year  after year, the HA head keeps changing -- probably   for the same reason. Our antibodies learn to  spot it, so the virus changes to evade them.  Which means researchers have to design  yearly flu shots based on what HAs they   think will be kicking around out there.  And as the virus continues to mutate,   our flu shots can no longer show our  immune system what it looks like.

This new study reports a clinical  trial of a vaccine that instead   targets the stalk, which varies far  less across different flu strains.  Which might be because it faces less pressure  from our immune systems, or that it needs   a very specific shape to do its job -- so  it can’t mutate or it will break. Or both. This was a Phase 1 trial that included 65  human participants, which showed that the   vaccine was safe, and produced a strong immune  response that lasted at least 18 months.  Now, as we’ve said a few times this year as  we’ve followed the development of COVID vaccines,  .

Phase 1 trials are just the  first step of human testing.  Next, the researchers will  move on to bigger Phase 2 and   3 trials to rule out rare side effects  and continue to demonstrate efficacy. The researchers also point out that this  version of the vaccine only works against   certain types of HA proteins, called group 1 HAs.  Which means this isn’t a universal flu vaccine   yet. But research is underway to broaden the  scope of this vaccine, to theoretically make   it work against a wide variety of flu  viruses -- even new pandemic strains.

It’s a step towards a universal flu  vaccine, which would save a lot of   lives -- not to mention the convenience and  reduced cost of only needing one vaccine. In order to defend against a disease,  we need to understand how it works,   but that’s not always easy. In another new study published  in The Lancet Microbe,   researchers have discovered a series of  mutations that might help explain why   certain common bacteria are harmless  to most people but deadly to others.

The bacteria in question  are Neisseria meningitidis,   and they’re found in the noses of  10 to 15% of the human population. Most of the time, these bacteria are no problem,   but in some cases they can cause  bacterial meningitis -- an infection   that can affect the central nervous  system and cause death within hours. In this new study, researchers compared  harmless and harmful versions of the bacteria   and found a surprising difference in their RNA.

RNA is a molecule similar to  DNA, and one of its main jobs   is to convert the messages contained  in the genetic code into proteins. But RNA can also have non-coding jobs, such as  regulating when cells perform certain functions. In this case, they were  looking at RNA thermosensors,   a form of RNA that alters cellular  activity in response to temperature.

After looking at thousands of RNA variants,  the researchers identified five versions of  . RNA thermosensors that seemed to be more  common in bacteria that cause meningitis. These RNA variants seem to help  the bacteria protect themselves.

In order to evade our immune system, the bacteria  form protective capsules around themselves. These mutated forms of RNA all help the bacteria   produce particularly large and  numerous defensive capsules. Being able to activate these  capsules in response to temperature   might help the bacteria survive in  the warm depths of our nasal cavities,   not to mention when our bodies  run a fever during infection.

This discovery gives us a molecular  warning sign to look out for. The researchers designed a method to  screen bacteria for these RNA variants,   which in the future could be worked  into a medical test that doctors could   use to spot these harmful microbes  before a severe infection takes hold. This is also the first time that a non-coding  RNA molecule has been found to be involved   in bacterial disease progression  in humans.

So it might also help   guide future research to similar unexpected clues. Cutting edge research isn’t the  only way to improve global health.   You -- yes, you -- can help too,  and score neat socks in the bargain. I’m talking about DFTBA’s Awesome Socks  Club, a charity sock subscription where   you get a fun pair of socks designed by  a different designer every month in 2021. 100% of the after-tax profits go to decrease  maternal and child mortality in Sierra Leone,   which is one of the most dangerous  places to be pregnant in the world.

The catch is that you have to  order by TODAY, December 11th,   so we know how many socks to make. You can  learn more at AwesomeSocks. Club/scishow. [♪ OUTRO].