Israel, in competition with health ministries around the world, is negotiating to acquire more vaccine or accelerate the delivery of existing orders. At least one shipment of a million doses of the Moderna vaccine will arrive in Israel in early January, rather than in March as was originally planned, according to Israel’s Channel 12 News. But thousands of already booked vaccination appointments will still have to postponed, officials said.

Ministry of Health Director General Chezy Levy said over the weekend that while the country remains on track to vaccinate some 2 million people by the end of January, he expects a two-week break in first-dose vaccinations to reserve supplies for the follow-up doses for the elderly and immunocompromised population.

Israel has relied initially on the Pfizer-BioNTech vaccine, manufactured in Belgium and given in two doses spread several weeks apart. Levy said that the government is “working intensively” with vaccine firms to deliver more doses.