Post-vaccination COVID-19 mortality in Israel and Europe

Vaccination efforts against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus disease (COVID-19) pandemic, have been initiated in many countries. Europe and Israel were among the first to vaccinate residents.

Now researchers from the University of Aix Marseille and the advisory group Creativ-Ceutical wanted to find out whether these vaccination campaigns have effectively reduced deaths in Europe and Israel.

The study, which was published on the pre-print server medRxiv *, confirms the strong effectiveness of the COVID-19 vaccination based on real public data in terms of protection against death.

Vaccination efforts against COVID-19

The coronavirus pandemic first appeared in the Chinese city of Wuhan in December 2019. From there, it has spread to 192 countries and territories. To date, over 171 million people have been infected with SARS-CoV-2, of which more than 3.68 million people have died.

Due to the severity of the outbreak, researchers and vaccine manufacturers worked tirelessly to develop effective and safe vaccines. However, in the second half of 2020, new variants of concern emerged that threatened the effectiveness of these vaccines.

One of the first variants reported was variant B.1.1.7 (alpha), which appeared in the UK in September 2020. At the same time, variant B.1.351 (Beta) appeared, which is known as the South African variant, followed by the Brazilian variant, also known as P.1 (Gamma). Recently, India reported an exploding number of cases related to the advent of a new variant called the B.1.617 variant (Delta) or the Indian variant.

Variant B.1.1.7 showed increased portability and hospitalization. Some studies have shown that the variant can increase the risk of death associated with COVID-19. The B.1.351 variant was found to have increased transmissibility and immune defenses, which makes some vaccines less effective.

The global vaccination campaign, which aims to ensure social herd immunity, started in December 2020. Scientists set the threshold for COVID-19 herd immunity to be between 60 and 70 percent of the population.

However, despite widespread vaccination, some people are still reluctant to receive the vaccine. Scientists warned that vaccine hesitation and the spread of new variants could prevent populations from gaining herd immunity.

Israel is leading the vaccination campaign against COVID-19 as it was way ahead of other countries in the proportion of vaccinated residents, exceeding 62 percent at the end of April 2021. The UK and US have achieved 50 percent and 42 percent, respectively.

Vaccines that have received emergency approval (EUA) from the Food and Drug Administration (FDA) include Pfizer-BioNTech with 95 percent effectiveness in preventing symptomatic COVID-19, Moderna vaccine with 94.1 percent effectiveness, Oxford -AstraZeneca with a 70.4 percent effectiveness, Johnson & Johnson with 66.5 percent effectiveness, and Novavax with 96.4 percent effectiveness.

The study

In the current study, researchers wanted to estimate the real impact of vaccination on COVID-19 mortality based on publicly available data from Europe and Israel. The team used time series analysis with nonlinear mixed regression models.

Cumulative number of COVID-19 deaths per 1 million population in all countries

The study, in which 32 countries across Europe including Israel participated, mainly focused on the daily evaluation of COVID-19 deaths. In addition, the team also looked at the percentage of residents vaccinated and the proportions of SARS-CoV-2 variants across the strains.

Based on real public data, the study confirms the effectiveness of the COVID-19 vaccination, albeit at a lower level than expected in clinical studies. This means that there is no indirect protection for people who have not been vaccinated. In addition, the effectiveness of the vaccination against mortality seems to be somewhat lower in variant B.1.1.7 than in other variants.

Average proportions of SARS-CoV-2 variants in the countries between January 2020 and April 2021

Average proportions of SARS-CoV-2 variants in the countries between January 2020 and April 2021

Finally, this analysis confirms that reducing mobility, as well as mobility between countries, is an effective way of reducing COVID-19 mortality and that there may be seasonal variations in COVID-19 incidence.

*Important NOTE

medRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, that guide clinical practice / health-related behavior or are treated as established information.

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