Determining the duration of protection provided by coronavirus vaccines is particularly important in determining the vaccination schedule and making public health decisions.
The Doctors of the Therapeutic Clinic of the Medical School of the National and Kapodistrian University of Athens Theodora Psaltopoulou, Giannis Danasis, Panos Malandrakis and Thanos Dimopoulos (Rector of EKPA) summarize the latest data from the relevant publication of an article in the Lancet by DR Feikin et al. : https: //doi.org/10.1016/S0140-6736 (22) 00152-0).
The researchers conducted a systematic review and meta-analysis of all relevant articles in the literature from June 17, 2021 to December 2, 2021.
The studies included were randomized clinical trials and observational studies. A total of data from 18 studies, which were performed before the predominance of the Omicron strain, were included.
Based on the critical evaluation of the studies, the probability of error (bias) was judged low for the 3 studies, moderate for the 8 studies and severe for the 7 studies. 78 COVID-19 vaccine efficacy evaluations were performed, namely 38 for Cominarty vaccine (Pfizer / BioNTech), 23 for mRNA-1273 (Moderna), 9 for Ad26.COV2.S (Johnson) and 8 for Vaxzevria (AstraZeneca) .
After how long does the effectiveness of the vaccine decrease?
Overall, the efficacy of full vaccination against SARS-CoV-2 infection decreased at 21 months post-vaccination by 21% compared with efficacy at 1 month post-vaccination regardless of age.
In older vaccinated persons (over 50 years) efficacy over the same period decreased by 21%.
In addition, the efficacy of full vaccination against symptomatic COVID-19 disease was reduced at 25 months post-vaccination by 25% compared with efficacy at 1 month post-vaccination regardless of age. In older vaccinated persons (over 50 years of age) the efficacy against symptomatic COVID-19 was reduced by 32% over the same period.
In addition, the efficacy of full vaccination against severe COVID-19 disease decreased at 6 months post-vaccination by 10% compared with efficacy at 1 month post-vaccination regardless of age.
In older vaccinated (over 50 years) the efficacy against severe COVID-19 disease during the same period was also reduced by 10%. Overall, the efficacy of the vaccine against severe disease remained at levels above 70% over time up to 6 months after vaccination. Decreased efficacy of vaccines against SARS-CoV-2 infection can be attributed to the decline of immunity to the virus over time, as well as to the emergence and prevalence of new strains of the virus.
Latest News
Auctioning Ten Hotels across Greece Each Valued Above 2 Million Euros
Scheduled throughout the summer from mid-June to October, these auctions feature hotels spanning from three-star accommodations to luxurious five-star resorts, each offering varied facilities, capacities, and amenities.
ELSTAT: 15.7% Surge in Agricultural and Livestock Prices for April 2024
The 15.7% surge in April 2024's output price index is primarily attributed to a substantial 23.7% hike in the crop output group, driven mainly by the price increases in olive oil and fruits.
Mitsotakis to Bloomberg: Early Repayment of Bailout Loans
Greek Prime Minister cited an early repayment of eight billion euros in bailout loans, which Bloomberg said corresponds to three years of installments
Greece’s Economic Revival Draws Investors
Both foreign and domestic investors are seizing the moment, ushering in a wave of significant deals across various sectors like banking, technology, food, energy, logistics, and hospitality.
Skopelos Island in Greece Captivates French Tourists
To capture the romantic essence of "Mamma Mia," the Municipality of Skopelos released an original music video featuring pianist Elena Xidia.
Second Wind Farm in Greece by EDPR
The wind farm “Erimia” is located at the town of Malesina in the administrative region of central Greece, with a 35W power capacity
Greek Employment – ManpowerGroup: Sectors Hiring in Q2 of 2024
The Information Technology sector leads as the most competitive at 38%, despite a 5-point drop from last quarter and 1 point from last year.
Greek PM Pledges Changes After ‘Concerning’ Election Result
Greek PM Kyriakos Mitsotakis said voters sent a clear message of trust in European elections but want improvements.
Eurobank Increases Stake in Hellenic Bank to 55.42%
Sources within the bank anticipate that this investment will propel Eurobank's stake up to 65% by the summer, paving the way for its proposed absorption of the Cypriot bank.
ELSTAT: Industrial Production in Greece Up by 10.8% in April
Looking at the broader picture, the average index for the period from January to April 2024 showed a solid 5.3% rise compared to the same period in 2023.