Germany on Thursday recommended a fourth coronavirus vaccine for at-risk groups, following in the footsteps of Israel and several European countries.

Germany's STIKO vaccine commission said a top-up shot for the most vulnerable was necessary after recent data showed "that protection against the currently circulating Omicron variant wanes within a few months of the first booster vaccination".

The fourth jab should be given to people over 70 and anyone over the age of five with a weakened immune system, STIKO said, as well as to those working in medical and care facilities to limit the impact of quarantine and illness on staffing.

Israel became the first country worldwide last month to start rolling out fourth Covid-19 shots, initially to the elderly and health care workers. It has since made the additional jab available to all vulnerable people over the age of 18.

Denmark, Hungary and Spain are also offering fourth jabs to high-risk groups, as are other countries including Chile and Brazil.

The move has not been universally welcomed, with the World Health Organization repeatedly warning wealthier nations that they cannot boost their way out of the pandemic.

"Blanket booster programmes are likely to prolong the Covid-19 pandemic, rather than ending it, by diverting supply to countries that already have high levels of vaccination coverage, giving the virus more opportunity to spread and mutate," WHO chief Tedros Adhanom Ghebreyesus said in December.

Germany's decision comes as the European Union's most populous nation is grappling with record infection numbers fuelled by the highly contagious Omicron variant.

Germany recorded more than 236,000 new cases over the past 24 hours on Thursday, according to the Robert Koch Institute.

Just under 75 percent of the German population is double jabbed, a slightly lower rate than in other western European countries such as France and Spain.

More than 53 percent of Germans are triple jabbed.

Germany only uses the mRNA vaccines made by BioNTech/Pfizer or Moderna as top-up jabs.

STIKO recommended at least a three-month gap between the two booster doses for high-risk groups, and six months for health care workers and carers.

The expert body does not recommend a fourth dose for those who caught the virus after their third shot.