Study: 4th dose of mRNA Covid-19 vaccine provides little additional protection

Israel, which started the fourth dose applications of the Covid-19 vaccine late last year, conducted a study on the effectiveness of the vaccine. The scientists concluded in a study that the fourth dose provided only a small amount of additional protection over the third dose.

Protection may be higher in the elderly and chronic patients

A study from the US Centers for Disease Control and Prevention (CDC) found that the third dose of mRNA could provide an important protection against diseases caused by the Omicron variant of the Covid-19 vaccine. He showed that he has the place. Data from the study also revealed that the third dose of vaccine protection against infection dropped significantly after about four months.

Thereupon, a study was conducted on the effectiveness of the fourth dose in Israel, which was the first country to apply the fourth dose of Covid-19 vaccine. In the study of both the Pfizer and Moderna vaccine, only minor differences were observed in positive Omicron cases when comparing the four-dose groups with the three-dose control groups. However, scientists say the fourth dose may offer a more protective effect in older and chronically ill people.

18.3% of the participants in the Pfizer group and 20.7% of the participants in the Moderna group were infected with the Omicron variant, while this rate was 25% in the three-dose control group. It is stated that the majority of the participants in the study are young and healthy individuals.

An as yet unpublished study of the efficacy of the fourth dose of mRNA vaccines in people over 60 years of age, except for studies in Israel, found that the fourth dose significantly reduced severe illness compared to three doses.

Julian Tang, a clinical virologist from the University of Leicester, said that while the studies were beneficial, new Covid-19 vaccines designed against Omicron were needed. Simon Clarke from the University of Reading mentioned that it is necessary to keep vaccines up to date in order to better target new variants.