The results of the first round of the serological study in Spain have shown that Spain is far from having group immunity. In fact, about 5% have tested positive, and to have group immunity, 60-70% of the population must be immunized, either because the infection has passed and has produced antibodies, or because it has received the vaccine (there is no vaccine to protect it from covid-19).
Epidemiologists expected the results of this serological study, since SARS-CoV2 infection is asymptomatic in many cases, due to the prevalence of the first pandemic stroke. Through the detection of IgG antibodies they have been able to know the infected percentages and the generated antibodies. Two additional shifts will be performed to confirm and complete the results.
The results show that in Hego Euskal Herria the seroprevalence is 4.4%: Araba 7.2%, Navarra 5.8%, Bizkaia 3.9% and Gipuzkoa 2.8%. A total of 7,350 people have performed a rapid test whose results have been extrapolated to the population as a whole.
Data indicate that there are no large differences in seroprevalence between women and men. 87% of prisoners previously issued in a PCR test had antibodies. Among those who suspected, the more symptoms they had, the more possibilities of antibodies. Many (43%) lost smell. On the other hand, 2.5% without symptoms gave positive.
In general, in large Spanish cities (of more than 100,000 inhabitants) the prevalence is higher than in the villages: 6.4%. By age groups, in children and young people the seroprevalence is lower than in adults, while in adults the percentage is similar in all age ranges.As for the employment situation, both in retirees and in the employed, the percentage is somewhat higher than the average (6.1% and 5.8%)
According to a study published in France on 13 May in the journal Science, seroprevalence is 4.4%. As in Spain, there are differences between territories, Ipar Euskal Herria being one of the territories in which the infection has been less widespread. Researchers warn of the danger of a second wave. Of course, since the beginning of the pandemic, there is much that has been learned along the way.