Ljubljana - Those who have received Johnson&Johnson's single-shot Janssen vaccine as their initial jab against Covid-19 will be able to get a second booster shot due to Austria's vaccination rules, the national advisory committee on immunization has decided.

The committee's head Bojana Beović told reporters on Tuesday the reason to expand eligibility for the second booster shot was that Austria does not recognise the single dose Janssen jab as a full vaccination against Covid-19.

However, there was "no good scientific reason" for the change affecting the group as the Janssen vaccine is defined as a single-dose vaccine and provides basic protection against the disease, she said.

Therefore, those who would like to get the second booster jab after the initial Janssen jab would need to sign a statement to receive one.

Under recommendations adopted by the advisory committee last week and released by the National Institute of Public Health today, the second booster or 4th shot is recommended to immunocompromised persons after a break of between three to six months since the first booster.