Israeli Study Finds 4th COVID Vaccine Cuts Infection Rates Slightly before Age 60

According to a new Israeli study, the fourth dose of the coronavirus vaccine does not make much of a difference when it comes to defending young and healthy people from getting infected. However, it further revealed that it does offer these people ‘moderate’ protection when it comes to developing the symptomatic illness. The New England Journal of Medicine published the findings after peer-reviewing. The study had been conducted during the Omicron wave during which Israeli health workers had been monitored. It is likely that the research will have an impact on international medical discussions on the topic of rolling out the fourth dose of the vaccine for the general population. 

Last month in a press briefing, Dr. Anthony Fauci, the lead epidemiologist in the United States, said that they were monitoring cases of fourth doses were carefully in the White House. There has also been speculation that the fourth dose could soon receive the approval of the US Food and Drug Administration (FDA) for the general population. A specialist of infectious diseases at Sheba Medical Center, Prof. Gili Regev-Yochay stated that research made it evident that the additional dose did not do much to curb the spread of the virus. 

The study had been conducted at her institution outside of Tel Aviv and some of its health workers had been tested, who were below the age of retirement. Regev-Yochay stated that where the effectiveness of the fourth dose against infection is concerned, it became evident that infection rates were only slightly lower in vaccinated individuals as compared to those in the control group. This was true for vaccines of both Pfizer and Moderna. Those who had received the fourth shot of the COVID-19 vaccine were 30% less likely to get infected, as opposed to those who received three doses. This was for people who had received the Pfizer shot. 

As for people with the fourth Moderna shot, they were 18% less likely to get infected. However, Regev-Yochay stated that the impact against symptomatic illness was more pronounced. After the fourth shot of Pfizer, the people were 43% less likely to suffer from any symptomatic illness, while it was 31% for Moderna. She added that health workers who were below the age of retirement had participated in the research, so it does not provide any details about the effectiveness of the fourth those in the elderly. The elderly are the primary target of the fourth dose in Israel and a few other countries, including the UK.

The authors of the study wrote that the research shows that the benefits of the three doses of the vaccine that had been developed for the original strain of the virus had reached a limit where the immune response is concerned. Hence, the boosters were not improving the immunity, but only restoring what was waned. This indicates that giving the fourth dose to young and healthy people can only give marginal benefits. But, the research does provide reassurance about the safety of the fourth shot. There were 600 participants in this study and 270 of them were given the fourth shot of either Pfizer or Moderna vaccine.