COVID-19 : Coronavirus | How long it will take for the COVID vaccine to take effect

The vaccination plan against the coronavirus in Spain is scheduled to begin next January. The Ministry of Health has differentiated 15 social groups that will be vaccinated according to the priority established by the health institutions. However, as confirmed by numerous specialists, preventive measures will continue to be applied, as the immunity provided by vaccines is not instantaneous.

For example, The vaccine patented by the companies Pfizer and BioNTech shows, according to the manufacturers themselves, an efficacy of 95% 28 days after the first dose. This means that at the time of being vaccinated you are still exposed to contracting the disease. If we combine the period of time necessary to achieve immunity with a vaccination campaign in phases in which immune persons will coincide with other candidates to become infected, it is certain that preventive measures will be maintained, at least, until reaching herd immunity.

In fact, an expert in vaccine development and research professor at the Margarita Salas Center for Biological Research, Vicente Larraga, estimated that “the vaccines begin to take effect between 15-28 days after the injection of the first dose.”


Larraga himself ventured, in an interview on Cadena SER, that Vaccination cannot begin until March. “The problems will be more logistical than at the permitting level. Distribution is very complicated and moving 300 million boxes is not easy. It takes more than a month to distribute so many doses “, he reflected.

However, the Ministry of Health insists that vaccination will begin in January. The Minister of Health, Salvador Illa, has confirmed the purchase of 140 million doses, which will immunize some 80 million people.