Fighting viruses

So far we’ve learnt that viruses aren’t cells. They aren’t alive. They’re just biological elements that interact with preexisting life forms that are actually capable of carrying out life chemistry on their behalf. In some ways viruses are biological entities like seeds. They are biological in nature but not alive except in special circumstances where the environmental input is greater than for living organisms.

How do you fight something that’s not even living?

At the point of infection, it becomes alive by virtue of its replication activity. Therefore the only way to directly target viruses is by interfering with the replication event. Antivirals work this way by targeting one of the many stages of infection and replication:

1. virus attachment
2. release of its contents into host cell
3. synthesis of virus components
4. assembly of new viruses
5. release to infect more cells

There are many types of drugs available that aim to target DNA synthesis by binding the enzyme responsible for its synthesis, so no further nucleic acids can attach and replicate. Others prevent the attachment of the virus onto the surface of host cells by blocking their attachment proteins.

Overall, the efficiency of antivirals at fighting viral disease once infection has already taken hold is poor. Therefore, the focus is on prevention of further spread of the virus in the affected population.

In 2014, an Ebola outbreak occurred in West Africa. The mortality rate was very high, over 50% and higher for those not hospitalised. A cure did not exist so most efforts went into prevention of spread. This involved three broad areas:

Firstly, contact tracing was implemented. This involved keeping track of all diagnosed cases and anyone who’d come into contact with the patient. They would be monitored for 21 days to see if they, too, became infected as a result of the contact.

Secondly, raising awareness in the affected communities was key to making sure residents knew of Ebola, the risks, symptoms and spread, and encourage stricter hygiene practices such as…

Test Call to Action!