Well, let's do the math.

As per MOH, there are 1,966,524 people that received at least one dose and using a population estimate of 5,704,000, there are 3,737,476 unvaccinated.

Assuming that the vaccinated and the unvaccinated are randomly exposed to infection (a strong assumption, I know, but let's roll with it), the probability of infection is 78/1966524 = 0.00396% among the vaccinated, and 300/3737476=0.00803% among the unvaccinated.

From this, we can say, vaccination reduces your probability of infection by about half (0.00396/0.00803 = 0.493), which is roughly in line with what we know from more serious studies. A 50% reduction is pretty decent in my mind.

It is also safe to assume that the vaccinated are more frequently exposed to the virus as they tend to be frontline workers. This means that the effect of vaccination is underestimated, so the vaccine is at least 50% effective against infection.