The Schengen visa allows not only travellers to enter Spain, but also all other countries in the Schengen area. These include the four third countries listed above. In response to the COVID 19 pandemic in 2020, almost all Schengen countries have put in place border controls. Several of these controls have prevented EU and Schengen citizens from entering, allowed entry only to citizens or residents of the country, as well as priority transport such as the transport of food.  On 27 March 2020, the European Commission published “Guidelines for the Exercise of free movement of workers during the initiation of COVID-19”, the finding that Member States should allow cross-border workers “unhindered access” and ensure a “smooth transition” to the internal borders of Schengen when they are in a “critical profession” (for example. B, health professionals, health professionals, pharmaceutical and medical service workers/food/transportation/major infrastructure, engineers, information and communication technology professionals, firefighters/police officers/penitaires/safety officers, fishermen and security officials). In addition, any health screening for border workers must be carried out under the same conditions as nationals of the Member State in the same professions.  Although 26 countries are in the Schengen area, including most continental European countries, not all European states are in the area where border controls have been abolished. Among the countries we associate with Europe, which are not part of the Schengen area, there are Eastern European countries such as: the Schengen countries are the European countries that have signed the Schengen Agreement. These countries work at internal borders without controls, allowing free movement between participating countries. The Schengen rules stipulate that all air carriers carrying passengers through the external border of Schengen must check, before boarding, whether passengers have the necessary travel documents and visas upon entry.  Air carriers that carry third-country nationals without proper travel documents are subject to fines and are required to return those refused to the point of departure.  The purpose of this measure is to prevent illegal immigration.
Since immigrants have the right to apply for asylum at border checks at EU ports of entry, while such applications must be made in person in the country where asylum status is sought, this measure has the effect of preventing potential applicants from boarding public transport to the Schengen area (unless they have already obtained a Schengen visa or are visa-free).