On Viruses & Vaccines

So now that we understand what viruses are and how they work, and we’ve looked at some of the most common viruses affecting us today, we can now take a look at some of the treatment methods we can use to fight these guys off.

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Not Antibiotics

Despite growing concerns, antibiotics are the go-to defence for bacterial infections. download (25).jpgHowever, because viruses and bacteria are so different, antibiotics don’t have the same effect on viruses. For this, a special class of drugs has been developed known as antivirals. Usually antibiotics work to kill their target bacteria. However, antivirals simply work to impair the function of the virus to prevent it successfully infecting its host.

If you recall the Virus Life Cycle (attachment, penetration, uncoating, replication, assembly and release), different antivirals target each stage of the life cycle.  Antivirals can either:

  1. Prevent the virus from entering the host cell in the first place. Antivirals do this by either physically blocking entry into the cell, or by altering the protein on the particle that usually recognizes the host cell the virus is targeting. Some antivirals also prevent the virus from shedding its outer coat and injecting itself into the cells.
  2. Antivirals can also work to disable the genetic machinery of the virus particle. Doing this prevents the virus from replicating its DNA and inserting it into its host’s genome.
  3. Other antivirals work to prevent assembly of the new viral particles after they’ve been replication, and finally some prevent the release of new viral particles out of the host cell and into the rest of the body.

Why Vaccines Matter

Recently, a new wave of the “anti-vax” movement has become popular in the parts of the US and the rest of the world. This paranoia is based on pseudo science linking vaccines to autism in children. (As in literally: the anti-vax movement is based on a 1998 study by a UK researcher named Andrew Wakefield. The study has since been disproven and Wakefield was struck off the UK medical register for lying and abusing the children in the study. Yet, people still believe it.)

download (26).jpgVaccines are based on a concept known as passive acquired immunity (There are 4 types of immunity, but that’s for another day). Acquired immunity basically happens when you are exposed to a virus or bacteria, so your body produces antibodies to fight it off. Once these antibodies are produced, they remain in your body to recognize the virus if it comes around again, and protect you from future infections.

Vaccines involve injecting small amounts of a modified version of the virus into the body in order to allow it to produce the defending antibodies. The virus is usually attenuated (disabled) or killed to prevent the vaccination causing actual infection. Occasionally, live viral particles are also used but in very small concentrations. Some vaccines actually inject artificially synthesized antibodies into your system, rather than leaving your body to create them.

By ensuring you are up to date on your vaccinations (this also includes regular adult vaccinations e.g. yearly flu vaccines) you are making yourself less susceptible to some of the most common (and deadly) viruses.  download (27).jpgOne of the trickiest things about viruses, however, is their rapid mutation rate. This means that scientists are always working to come up with new vaccines because the viruses keep changing, rendering the old treatment ineffective. This is seen especially in the treatment of HIV infections as HIV has a very high mutation rate.

Why Don’t We Have A Vaccine For Everything?

This question comes up every time there’s a new viral outbreak. The truth is, vaccines take a pretty long time to develop.  virus.jpgAfter researchers have grown the vaccine and figured out the best strategy to combat it, extensive testing and trials must be done to determine the safety of the vaccine before it can be released for human use. Some of these trials can take up to 2 years, which is why this type of drug development usually takes so long. And for some viruses, no suitable vaccine has yet been found.

 

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