The Turnstone: talking about vaccines #35

Viruses, cancer and the HPV vaccine (4 minute read)

Welcome to The Turnstone. Here, I help people understand important issues such as Covid-19, climate change and conservation. I send my articles out every Sunday - if you’d like them emailed to you directly, you can sign up to my mailing list.

Viruses and cancer

When we think about the causes of cancer, most of us probably think of causes like cigarette smoke, environmental pollution or radiation. However, scientists have known for over 100 years that some cancers are caused by infectious agents such as viruses. I’ve written about some of these viruses before, when I wrote about hepatitis viruses. Both hepatitis B and hepatitis C are linked to liver cancers. But when I wrote that article, I didn’t look at the link between viruses and cancer in any depth.

It is hard to know exactly how many cancer cases are caused by viruses, because different sources give different numbers, but the number appears to be around 10%. In developing countries, that figure is much higher. Most viruses have no connection to cancer – there are fewer than ten viruses that are currently considered to be cancer-causing.

The connection between certain viruses and cancers is not a simple one, where infection with the virus directly leads to cancer. I’ve tried to find a good diagram or video explaining the process, but most of the explanations were aimed at medical professionals. The simplest explanation I’ve found suggests that certain viruses can interfere with how cells work, and over time this can lead to uncontrolled growth of cells, that is, cancer. The website below gives a reasonably simple explanation.

Why do some viruses cause cancer? - Morgridge Institute for Research (1 minute read and 3 minute video)

The following article is a little heavy on the medical terminology, but for those who are particularly interested, it gives a good overview of the link between viruses and cancer.

The 7 Viruses That Cause Human Cancers (asm.org) (8 minute read)

Human papilloma virus (HPV)

One of the most important cancer-causing viruses is the human papilloma virus, also known as HPV. It’s not a single virus, but a group of more than 100 viruses. Most of them cause warts (papilloma is a medical term for a wart). However, a few types are linked to cancer. There is a particularly important link between certain human papilloma viruses and cervical cancer – 95% of cervical cancer cases are caused by a few types of human papilloma virus.

Since I’m talking about the unpleasant subjects of warts and cancer, here’s something pretty, a New Zealand native hibiscus species (Hibiscus richardsonii. Image credit: Melanie Newfield)

Here is a good overview of the types of human papilloma viruses and their link to cancer, from New Zealand’s Immunisation Advisory Centre. As well as cervical cancers, these viruses can cause other types of cancer as well, in men as well as women.

Human papillomavirus (HPV) - Immunisation Advisory Centre (5 minute read and 2 minute video)

There is also good information about human papilloma viruses and cancer from the USA Centres for Disease Control.

Basic Information about HPV and Cancer | CDC (main page 3 minute read, with other pages 1-3 minute reads)

Vaccination

There is a safe an effective vaccine available which is effective against a number of different human papilloma viruses, including two types associated with genital warts and seven types associated with cervical cancer and some other cancers. The vaccine is sometimes known by the name Gardasil. It is usually recommended for children aged 11-12. In New Zealand, the vaccine is available free to those aged 9-27.

Gardasil is a type of vaccine known as a recombinant vaccine. It is made by genetically modifying bacteria or yeast cells, and then those modified cells make the vaccine. There is no genetically modified material in the final vaccine (I wrote an article about the use of genetic modification to produce vaccines – the link is below). Gardasil is a similar type of vaccine to the Novavax vaccine against Covid-19, but it is most similar to the Hepatitis B vaccine, which I wrote about a couple of months ago.

The GM dilemma - The Turnstone (substack.com) (13 minute read)

For more specific information on Gardasil, New Zealand’s Health Navigator website gives a good overview of the vaccine. The video on this site comes from New Zealand’s Ministry of Health and is particularly aimed at children of the age group who will be offered the vaccine at school. Some people may prefer to share this information with their children because it explains about the virus and vaccine without mentioning that the virus is sexually transmitted.

HPV vaccine | Health Navigator NZ (5 minute read and 6 minute video)

There is more in-depth information about the vaccine available from New Zealand’s Immunisation Advisory Centre.

Gardasil 9 - Immunisation Advisory Centre (8 minute read)

Information with a USA focus is available from the Centres for Disease Control.

HPV Vaccination: What Everyone Should Know | CDC (4 minute read)

Finally, here is a separate link to the video that I mentioned above.

Immunisation Year 8 protection against HPV - YouTube (6 minute video)

I will be holding an in-person Living Room Conversation about climate change at 11.30am on Sunday the 12^th of February, in Wellington. I still have room for a couple more people, so if you are interested in participating, please reply to this email to let me know.

The Turnstone is free, but if you would like to support my work with a monthly or annual subscription, click the “Subscribe now” button below for options.

If you would like to support The Turnstone with a one-off contribution, click the “Buy me a coffee” button below.