“Vaccine protection against Omicron is lower than for other variants”

IMDEA Networks researchers have participated in a study funded in part by the Coronasurveys-CM project of IMDEA Networks and the Community of Madrid

11 April 2022

Research for the fight against the coronavirus deserves even more institutional support, given the virulence of the new variants. This is demonstrated in an international study in which IMDEA Networks doctors Antonio Fernández Anta and Jaya Prakash Champati have participated, together with colleagues from other institutions such as University Carlos III of Madrid, the European universities of Rennes and Oporto, and American universities such as Southern California.

The object of the study is the efficacy of vaccines against infection with the Omicron variant. The study uses data from the Global COVID-19 Trends and Impact Surveys (UMD Global CTIS) project, in addition to data on variants collected by the global scientific virus initiative GISAID and the repository Our World in Data. The scientific publication ‘Using Survey Data to Estimate the Impact of the Omicron Variant on Vaccine Efficacy against COVID-19 Infection’ details the research and conclusions of this international team, which has worked with ‘machine learning’ techniques and models (‘random forests’ included) for a more refined search and analysis.

“The data from our study -says Fernández Anta- showed that the vaccinated population is still more protected against being infected with Omicron than unvaccinated people, but the difference is smaller than with other variants”. This result was first observed in South Africa, and has been confirmed in other countries with a significant presence of Omicron. Champati highlights how ” two doses of the vaccine conferred better protection compared to one dose against both Omicron (vaccine efficacy 30% vs 9% in South Africa) and Delta (81% vs 51%) variants “.

The researchers underline the interest of the study in the African country for being “the first epicenter” of this variant, which has been thoroughly analyzed thanks to advances in surveys and mathematical and statistical methods, such as those of the CoronaSurveys project. An enormous volume of data collected through open and anonymous surveys has been analyzed, an initiative of great importance in countries where, for various reasons, official data is not reliable. “Therefore, the results of our research offer a new perspective and come closer, with the support of official statistics, to a more realistic estimate of the incidence.”, the researchers emphasize.

All this research development contributes and will contribute, for example, to the better measurement of vaccine efficacy during the pandemic, which is key to facing new measures, not only for the current pandemic but also for future health threats. “We believe (the researchers note) that these data reflect that improvements are needed in vaccine development and deployment (in a significant way in the case of Omicron) and that anticipatory work is critical, as well as that of evaluating their efficiency”.