The risk of death or need for artificial breathing support in severely ill COVID-19 patients who have had four doses of the vaccine is half that of severely ill patients who have received only three doses.
The finding is from a study that was carried out in Israel, preliminary data from which was presented last week to the Health Ministry’s pandemic response team.
The study included 1,049 severe and critically ill COVID-19 patients age 60 and above in 14 hospitals during the second half of January.
The lead researcher was Dr. Tal Brosh, director of the viral diseases clinic at Assuta Ashdod University Hospital and secretary of the pandemic response team.
Some 773,000 Israelis have received a fourth dose of the vaccine. Israel’s coronavirus czar, Prof. Salman Zarka, said last week that 43 percent of adults over 60 have received a fourth dose. Another 600,000 received a third dose less than four months ago, giving them high protection from severe illness.
Prof. Ron Milo of the Weizmann Institute of Science presented additional information on the efficacy of the fourth dose in adults 60 and up, based on data from the Weizmann Institute, the Health Ministry and the Gertner Institute for Epidemiology and Health Policy Research. The study analyzed data from 1.2 million Israelis 60 and up who were eligible for a fourth dose, of whom around half received it.
The study found that the rate of confirmed infections among those with four doses of the vaccine was also half of that in those with only three doses. However, experts noted that protection declined over the eight-week duration of the study. As for efficacy in preventing severe illness, the experts showed that data from Israel indicates that in those 60 and over, four doses of the vaccine provides a protection level three to four times greater than three doses.
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The pandemic team also discussed expanding administration of the fourth dose to those aged 18 and above. People in Israel aged 18 and up may receive a fourth vaccine dose if they want, but Health Ministry policy is to give a second booster to people with a higher risk of severe illness if they are infected, including adults 60 and up, people with compromised immune system and health care workers and others who are exposed to large numbers of people.
Some meeting participants supported recommending a fourth dose to adults under 60 without specific risk factors. Others argued that expanding the population eligible for a fourth dose without explicit recommendation will compromise the public’s trust in the vaccine.
Of the team’s 35 members, 29 voted to allow people who want a fourth dose to receive it, and 22 voted to explicitly recommend a fourth dose to all adults 18 and up.
The team also discussed giving a third dose to children aged 5-11. Team members were divided on this question, with supporters of such a move believing that the third dose can extend the effect of the first two doses – and a 50 percent reduction in so-called long COVID in children.
Opponents said the inability to prevent infection even among the vaccinated, the widespread infection with the coronavirus among children and their relatively low risk of severe illness all argue against introducing a broad campaign for booster shoots for children. In a vote, 21 team members supported giving children 5-11 a third dose and the other 14 opposed the idea.
Most of the Health Ministry’s and the health care providers’ vaccination efforts target older adults, due to the understanding that younger people rarely develop severe COVID-19 at present.
The Health Ministry anticipates a rise in coronavirus infections and illness in April, due to large gatherings for Passover and for Ramadan as well as an increase in domestic and foreign travel. It is therefore postponing until May 1, from April, a temporary reduction in the availability of vaccines and testing and a relaxation of national preparedness.
The situation will be assessed toward the end of the month to determine what action to take. Zarka said that if illness rates are low, the indoor mask mandate might be lifted as soon as May 1.