COVID-19 virus SARS-CoV-2

Epidemiological Profile of Spain

The evolution of COVID-19 epidemiology in Spain between March 1, 2020 and September 12, 2021. The data is expressed as the raw weekly numbers of reported positive cases.

The trajectory of Spanish COVID-19 epidemiology provides clear evidence of a very slow herd immunity build up often interrupted by the implementation of very strict public health intervention measures and lock downs. It was atypical of the rest of the European continent as the dates of incidence peaks were somewhat shifted and did not coincide with the COVID-19 epidemiology profile observed in other European countries. Spain is also one of few countries where the second COVID-19 epidemic wave is spread into one continuous segment of numerous oscillating waves and peaks.

The first peak of the second wave was observed on November 8, 2020. It was followed by a steep drop undoubtedly caused by the combination of attainment of herd immunity to the prevalent strain of SARS-CoV-2 virus and the country's lock down. At the beginning of November 2020 only 29% of the Spanish population (46,7 million) became exposed to the coronavirus. However, the continuation of strict restrictions and lock downs did not prevent the subsequent rise to the second peak at the end of January 2021. By this time only 59% of the Spanish population was exposed to the coronavirus and began mounting its immune response to it. In addition country's vaccination program started to roll on December 27, 2020. However, the maintenance of lock downs and vaccination program under way did not suppress the epidemic. The State of emergency finally ended on May 9, 2021. This was followed by a massive COVID-19 incidence peak run up on July 25, 2021. By the end of July 2021 however, 91% of Spaniards had already been exposed to the pathogen and gained their resilience to the disease. This was reflected in the steep drop of the last peak together with substantially dropping infection fatalities (see below).

Thus the maintenance of painfully strict social distancing measures by the Spanish government together with government vaccination program had little effect on profound incidence fluctuations and overall epidemic outcome until natural herd immunity within the Spanish population became established.

Here, raw data of weekly reported cases is plotted together with the profile of Spanish infection fatality ratio (IFR). Despite very strict social distancing measures implemented by the Spanish authorities the COVID-19 epidemic in that country shows no sign of respite confirming the futility of the use of lock downs, and other severe restrictions to curb COVID-19 disease. In addition, in Spain the use of severe social distancing measures did not prevent excessive fatalities.

The mortality (IFR) at the beginning of 2021 associated with COVID-19 in Spain was excessive.

Data: WHO weekly reported SARS-CoV-2 virus positive cases.