So
Like the flu jab
Will you need to get one every year
no Kiwi, not at all
You need a flu jab (nearly) every year, because it is a different strain of flu most years. H1N1 one year, H1N7 another; there are a lot of flu strains!. Ontop of that the flu virus hypermutates a lot, so with time 1970 H1N1 does not look exactly like 2020 H1N1. However, if you have a jab against H1N1 you should stay immune to that strain for a long time
Corona virus on the whole has not really caused much danger, often going through the population with little effect ( a cold, a cough etc.
But in the 21st Century we have had 3 pandemics
SARS (severe acute respiratory syndrome) in 2003 which is called CoVid1, It started again in Chinese wet markets probably from bats or civets. There were about 10,000 cases and a death rate of 10% , many in health workers. It was contained within 6 months, because it was not "super" infectious, but was human to human transmissable.
MERS (middle-eastern respiratory syndrome) was an animal to human transmitting disease...i.e. you seem to get it from animals. That started in 2012, and still going on today, in small pockets in the middle east, but as say you get it from animals, and not many people have camels as pets. That is lucky as it is pretty nasty and kills around 34% of those infected. There have been aboy 3000 deaths. It never became human to human transmissable I do not think
CoVid19 is not as fatal as the previous, but is super infectious, which is why we have not been able to contain it. It is still thought to be between 1-3% fatal.
So if we can get a vaccine that protects against CoVid 19, it should be pretty good to protect us, until the next corona virus breaks out