The third Covid-19 dose increases the level and duration of protection against the Omicron variant and hospitalisation compared to two vaccine doses, finds a new study

The study showed that 2 vaccine doses provide only limited and short-lived protection against SARS-CoV-2 infection with the variant

The study was published in the journal PLOS Medicine

However, evidence is limited regarding the vaccine effectiveness of three vaccines over time

The team conducted a nationwide cohort study of all previously uninfected Danish residents aged 12 and older by accessing individual-level data

The team then estimated vaccine effectiveness using vaccination status as a time-varying exposure, adjusting for age, sex, etc

The study indicate that a third dose is necessary

The study also showed that there was less evidence of waning protection