COVID-19 herd immunity target to be reached on 19 May The 70% mark set by the Maltese authorities will be reached next week 12 May 2021, 7:00am by Kurt Sansone Herd immunity for COVID-19 will be reached today week if the vaccination rollout of first doses maintains the current pace. With 61% of the adult population aged 18 and over having received at least their first dose of the COVID-19 vaccine last Monday, the 70% mark set by the Maltese authorities will be reached on 19 May. On the same day, Malta can expect to have a third of its adult population fully-inoculated with two doses, or the single shot Janssen vaccine.