4th COVID-19 vaccine dose recommendation needs more data, some Israeli medical experts say

The recommendation by an Israeli panel to administer a fourth vaccine to those who are over 60 is being met with a tepid response by some of the country's medical experts, who believe more data is needed.

"I supported the booster recommendation in July. But that time we had better evidence. Today, we don't have any good evidence," said Dr. Dror Mevorach, head of the coronavirus department at Hadassah University Hospital Ein Kare in Jerusalem.

"I think there is a great question about the impact of this fourth booster. I'm not sure it will help." 

Mevorach told CBC News that unlike the decision to implement the third dose, which was met with wide approval, this recommendation is being questioned by some in the medical community.

"I would say that I got dozens of calls from both medical doctors and scientists saying to me that we think the same, that there's no evidence to give [a fourth dose} for the moment," he said.

The recommendation for a fourth dose to people over 60, those with compromised immune systems and health-care workers was made based on concerns of waning immunity of the three vaccines already administered, combined with the potential threat of an Omicron outbreak seen in other countries.

"The price will be higher if we don't vaccinate," Boaz Lev, who heads the advisory committee, told reporters following the panel's decision.

The recommendation was also welcomed by Israeli Prime Minister Naftali Bennett, who called it "great news that will help us overcome the Omicron wave that is spreading around the world."

It is currently being reviewed by Israel's director general of the Health Ministry, Nachman Ash. If approved, Israel would become the first country to roll out a fourth dose to some of its citizens. However there have been some reports that Ash might be stalling while he reviewed information from Britain that shows that Omicron leads to less severe illness than the Delta variant.

Dr. Ron Dagan, a professor of pediatrics and infectious diseases at the Ben-Gurion University of the Negev and a member of the expert panel, acknowledged that the recommendation was not based on data of fourth dose results "because there is no data."

"There's no data that we could base on our recommendation," he told CBC News in a phone interview. "But on the other hand, there are data that altogether made us worried about what's going on as a potential scenario in the upcoming weeks."

There is evidence of waning immunity against infection about three to four months after the third vaccine was rolled out, he said.

Dagan said the panel didn't believe a fourth shot would cause any harm, and it made an "educated guess" about Omicron's potential impact and the benefits and risks of offering a fourth dose.

"To the best of our judgment, the potential benefits, we believe, are bigger than the potential risks."