The Covid is rising again in Spain, with a particularly marked increase during September. The latest national report available from the Acute Respiratory Infection Surveillance System (SiVIRA), corresponding to the week of September 14 to 20, places the estimated incidence in Primary Care at 85 cases per 100,000 inhabitants, compared to 25.6 a week earlier.
The increase is also reflected in the tests conducted on patients with respiratory symptoms. The positivity of SARS-CoV-2 rose from 16.7% to 25.8% in one week. The coronavirus is thus the respiratory virus with the highest circulation among the analyzed samples, ahead of the flu, whose indicator was at 22.9 cases per 100,000 inhabitants.
The available data, however, do not show an equivalent increase in severity. The estimated rate of hospitalization due to Covid was at 0.8 cases per 100,000 inhabitants in week 38, compared to 1.2 in the previous week. The total of acute respiratory infections had also not reached the national epidemic threshold.
The increase started before September
The rise is not concentrated in a single week. In the week from August 31 to September 6, the positivity of SARS-CoV-2 was lower than that recorded later. A week later, between September 7 and 13, the rate of Covid syndrome in Primary Care had already increased to 11.3 cases per 100,000 inhabitants, compared to 8 from the previous week.
In that same week 37, the indicator that combines the incidence of respiratory infections with the positivity of the coronavirus estimated an incidence of 25.6 cases per 100,000 inhabitants. In the following week, that same indicator reached 85 cases.
The territorial behavior is also not uniform. In the Comunitat Valenciana, the data published by the regional health showed an increase in the incidence of Covid from 52 to 117 cases per 100,000 inhabitants in one week. The increase led to the advancement of the vaccination campaign for the groups considered priority.
In Murcia, diagnoses increased by 70% in one week according to the surveillance data cited by the regional health. In Galicia, an increase in consultations and admissions has also been observed, especially in the health area of Vigo, although health officials and consulted experts have pointed out that the increase occurs from previously reduced levels.
Andalusia, for its part, has detected an increase in cases both in Primary Care and in hospitals. The Board has classified it as mild and maintains surveillance because the levels of incidence continue to be low. The Andalusian Minister of Health, Antonio Sanz, has pointed out that it is still not possible to talk about the beginning of an epidemic wave.
XFG is the variant that circulates the most
The increase in cases is occurring with XFG as the main identified variant. The genomic characterization carried out by the National Center for Microbiology shows that this variant represents 61.95% of the characterized viruses in the sentinel samples from Primary Care since the beginning of the season until week 34.
The second identified variant is BA.3.2, although with a much lower proportion. The Ministry of Health indicates in its recommendations for the 2026-2027 season that XFG is the preferred option for the update of vaccines and that these vaccines are also expected to provide protection against BA.3.2.
The available data do not point to the emergence of a variant that is causing an extraordinary increase in severity. The Health documentation itself reminds that prior immunity, both from vaccination and from previous infections, is associated with lower clinical severity and a lower risk of complications.
Vaccination begins while circulation increases
The upturn coincides with the start of the vaccination campaigns against Covid and flu in much of Spain. The Ministry of Health recommends this season the Covid vaccine mainly for people aged 70 or older, residents in nursing homes and other closed institutions, people with certain risk conditions, and pregnant women.
The recommendation also extends to certain health and social health professionals and to cohabitants or caregivers of people belonging to risk groups, who can access vaccination as a measure of individual protection.
The new vaccines available for the season incorporate the update against XFG. Health includes among the authorized presentations mRNA vaccines and recombinant protein vaccines, with formulations adapted to the variants currently circulating.
The autonomous communities are applying different calendars. Some began immunization during September, while others have scheduled it for the end of this month or during October. Galicia started the campaign on September 28 in residences and centers for people with disabilities, while Andalusia has set October 1 as the start date for its seasonal campaign.
The current scenario is, therefore, different from that of the early stages of the pandemic. The main indicator that is growing is the circulation of the virus, not the severity of the cases. Monitoring in the coming weeks will allow us to verify whether the increase continues, stabilizes, or reaches a maximum before entering the months of higher circulation of other respiratory viruses.