Further questions can be answered via these two links:

https://www.health.govt.nz/our-work/diseases-and-conditions/covid-19-novel-coronavirus

https://www.immune.org.nz/covid-19-vaccines 

https://www.healthnavigator.org.nz/health-a-z/i/influenza/

https://www.healthnavigator.org.nz/medicines/c/covid-19-vaccine-and-other-vaccines/