Israel Approved Administration of COVID-19 Fourth Dose
Since the emergence of the novel coronavirus, numerous variants have emerged worldwide. They have been classified as Variant of Concern (VOC) and Variant of Interest (VOI) based on their increased virulence and high transmission rates. The Omicron was replaced with Delta Variant, and now China is again seeing a spike in infection rate.
Like many countries, Israel has seen a surge in cases due to the rapid transmission of the Omicron variant. According to the reports, there are two reasons behind the increased infection rate. One, the variant is strong enough to affect the immune system, and the other reason is the passage of more than four months since most adults had received their dose of the COVID-19 vaccine.
To control the spread of infection and reduce the pressure on healthcare facilities, Israel authorities have approved the administration of the fourth dose of the COVID-19 vaccine on 2nd January 2022, manufactured by Pfizer-BioNTech. All individuals above sixty years of age and at high risk of contracting the diseases or who have already passed more than four months since receiving the third dose are being prioritised for the fourth dose of vaccine.
The effectiveness of the booster shot against the infection and disease severity is not yet known. But the new studies are focusing on the effectiveness of the fourth dose compared to the three doses against confirmed infection and severe illness among the older population of Israel.
Researchers obtained the data from the Ministry of Health national database from the period 10th January to 2nd March 2022. The data is based on the vaccination status and demographic variables such as age, sex, etc., of the participants. Scientists included people sixty years of age & above and received four doses of the COVID-19 vaccine.
In this study, the researchers compared a four-dose group with two control groups. The first group contained individuals who were eligible for the fourth dose but had not received it, and the group was referred to as a three-dose group.
The other and the second group contained individuals who received a fourth dose 3-7 days earlier and were referred to as the internal control group.
The research indicates that compared to the three vaccine doses, given at least three months earlier, the fourth dose provides additional protection against confirmed infection and severe illness. In addition to this, the increased rate of infection was lower by a factor of two, and the frequency of severe outcomes was lower by a factor of 3 among people in the fourth week after receiving the fourth dose compared to the three-dose group.
The thing is, the maximum protection was observed in the fourth week after vaccination but decreased to approximately 1.1 by the eighth week.