The JCVI is examining the impact of a second round of booster shots.
They'll examine into Omicron Covid hospitalizations and how much immunity a third jab gives them before making any recommendations.
Immunocompromised patients already get a fourth dose, but the elderly and other vulnerable groups may soon be eligible.
It comes after Israel promised a second raise for healthcare workers and those over 60.
The world will follow in our footsteps,' said Prime Minister Naftali Bennett.
Meanwhile, Germany has purchased 80 million extra pills as its government backs an extra shot.
The fourth jab would be delivered four months after the third, according to the Telegraph.
‘We need more data,' said JCVI deputy chair Anthony Harnden. Unlike Israel, we need more evidence on declining immunity and vaccine effectiveness against hospitalisation.'
According to an Israeli health specialist presently sharing findings with the UK, the third jab's immunity is already waning.
Professor Nadav Davidovitch, director of the School of Public Health at Ben Gurion University in Israel, said this supports giving out a fourth.
‘It's a bit like the second dose a few months back. So some of us considered people who had their third dose more than four months ago should be vaccinated.'
Compared to Israel, the UK has seen a much larger surge of Omicron cases.
‘I think there will be people who will get a fourth jab - whether that will be everyone is still in doubt,' said Professor Adam Finn of the JCVI.
‘We need to watch how things go after this wave.
Some people who got their boosters early and are older or more vulnerable may require another jab, but that hasn't been decided yet.
It is still being reviewed and discussed, and we will make recommendations in the new year.'
Today, Germany's health minister stated he expects a spike in coronavirus cases in early 2022.
According to Karl Lauterbach, a fourth vaccine dose may be required to ensure optimal immunological response.
He told WDR 2 that unlike other European countries, Germany hasn't experienced a sudden surge in omicron infections.
‘That will alter around New Year's and the first week of January,' he continued.
In addition, the government is advising Germans to restrict their interaction during the holidays and to be vaccinated, including booster doses.
Officially, 70.7 percent of the population has gotten a full course of vaccines, with 35% having boosters.
Germany has seen recent protests against increased pandemic restrictions and a potential vaccine requirement.
Around 5,000 protestors gathered late Wednesday in Munich's city centre, police reported. Eleven were arrested.