The Israeli Health Ministry on Tuesday called on at-risk persons to wear masks during the High Holidays if they will be in closed spaces with many people.

Researchers have already tracked a number of mutations of the COVID-19 variant called BA.2.86. The variant manages to evade the immunity the body is able to provide from previous infections and accounts for a significant amount of current diagnoses.

The ministry also recommended wearing a mask when meeting with people who are in high-risk groups, and that anyone showing COVID-19 symptoms should isolate himself until the symptoms are over.

The announcement comes one week after the ministry instructed hospitals to test new admissions for COVID-19 amid the spread of the BA.2.86 variant.

According to the ministry, Israelis who have not received a COVID-19 vaccination in the past six months are more vulnerable. It advised people in high-risk groups, such as the elderly, the pregnant, the obese or individuals with serious pre-existing health conditions, to get vaccinated for both COVID and influenza.

Clinics have already begun administering annual winter flu shots.

The ministry also said it is preparing dedicated vaccines against the newest mutations.

The number of active COVID-19 cases in Israel is not clear. Health Ministry figures are regarded as partial because most Israelis have been testing themselves at home since the pandemic tapered off.

The Samson Assuta Ashdod University Hospital announced last week that the BA.2.86 variant now accounts for over 16% of cases in Israel. The hospital said its conclusions were based on Health Ministry data.

The High Holidays begin on Friday night with Rosh Hashanah.

BA.2.86 (the “Pirola variant”) is an Omicron subvariant of SARS-CoV-2, the virus that causes COVID-19.