The Turnstone: talking about vaccines #26

Covid-19 boosters and influenza vaccines (3 minute read)

In late May, New Zealand’s government announced that a second booster dose (fourth dose) of the Covid-19 vaccine would become available soon for those most vulnerable to severe disease. While many will welcome the chance to improve their immunity, some will feel uncertain and others will wonder when it all ends.

The resources shared here are aimed at helping people to have better conversations about second boosters, as well as another vaccine that’s important right now, the influenza vaccine.

Photo by CDC on Unsplash

Questions and answers about fourth doses from Your Local Epidemiolgist (6 minute read)

I’ve found this newsletter to be an excellent source of information throughout the pandemic. This article gives a good overview of fourth doses/ second boosters. It’s from a USA perspective, but much of the information is relevant to New Zealand and other countries using messenger RNA vaccines like the Pfizer and Moderna vaccines.

Fourth Dose Q&A - by Katelyn Jetelina (substack.com)

Advice from the World Health Organisation on additional boosters (10 minute read)

This article gives a good overview of the evidence behind a second booster dose. The short version is that the evidence is limited and only applies to the messenger RNA vaccines (such as the Pfizer vaccine widely used in New Zealand). There is evidence for some short-term benefit in people over 60 and those who are immune-compromised. The data so far suggest minimal benefit in healthy younger people.

However, compared with giving primary doses to unvaccinated people, the benefits are small. As much as possible, the priority should be to reach those who are still unvaccinated.

Interim statement on the use of additional booster doses of Emergency Use Listed mRNA vaccines against COVID-19 (who.int)

Influenza vaccine from the Immunisation Advisory Centre (2 minute overview, 9 minute in-depth)

As well as a general overview, this site gives more detail about the specific influenza vaccines in use in New Zealand. There are different vaccines for different age groups.

Influenza vaccine | Immunisation Advisory Centre (immune.org.nz)

History of influenza vaccination (7 minute read)

This article gives a history of influenza vaccination, starting with early attempts which focused on the wrong disease agent. Until the 1930s, researchers believed that influenza was caused by bacteria. At that time, viruses were still poorly understood, and couldn’t be seen with microscopes until the late 1930s – if you want to know more about the fascinating history of the discovery of viruses, I recommend the article I’ve linked here about tobacco mosaic virus.

The Antibody Initiative -- Chasing Influenza | National Museum of American History

Advice on influenza vaccines from the USA Centres for Disease Control (12 minute read)

Although the information is for the USA, much of it is relevant to New Zealand. One of the key points is that it’s difficult to make statements on how effective the influenza vaccine is, because that depends on the match between the flu variants used to create the vaccine and the flu variants which are spreading in the community. This page links to a number of studies on vaccine effectiveness if you want to get into more detail.

Seasonal Flu Vaccines | CDC