Are some people more susceptible to Covid reinfection compared to others?

According to data  from Denmark, which examined re-infections with the BA.2 Omicron subtype within 60 days of BA.1 infection, such re-infections were more common in young, unvaccinated people.

Other studies have suggested that vaccination with Covid-19 provides a significant increase in protection against reinfection because it enhances the body's immune defenses.

However, Omicron infection itself appears to be a weak immune booster, meaning that if you were infected during previous pandemic waves, the immune response is unlikely to be strengthened if you were infected with Omicron earlier this year.

Will the symptoms be milder after reinfection? In general, infections should be less severe the second, third, or fourth time because people have some sort of immune defense - especially if they have been vaccinated. However, there are always exceptions to this.