Vaccines against the new coronavirus can prevent covid-19, especially the most serious disease, but it is not clear to what extent they can stop the spread. This is why it is so important to continue to take protective measures to avoid new infections.
The current covid-19 vaccine can prevent people receiving the vaccine from getting sick, especially if they are seriously ill, they need to enter the intensive care unit. However, it is not yet known to what extent the currently approved drugs can also prevent the spread of the virus. In other words, the vaccinated person may be infected without serious symptoms, but will continue to be infected.
Therefore, despite having been vaccinated, All protective measures must be taken to avoid infection: Used for Face mask,washing hand, distance Safe and ventilation Enclosed space. He said: “We are not tired of repeating it.” Sonia Zuniga, Is a virologist at the National Biotechnology Center of the Advanced Scientific Research Council (CNB-CSIC).
Vaccines approved in Europe can induce good immune response And they usually have a high potency. But when its efficacy and safety were proven in clinical trials, it was only observed that the drug could prevent covid-19 and protect people at a higher risk of complications. There is no data on whether they also stop spreading the virus.
Evidence of immunity
The test results published so far show that, on the one hand, vaccines help build the immune system. Neutralizing antibody, Some IgG immunoglobulins found through serological testing. On the other hand, they also activate specific cells of the immune system- T lymphocytes-Train them to attack SARS-CoV-2 after infection.
This immune deployment prevents the virus from attacking the lungs, allowing them to settle and cause severe acute respiratory syndrome pneumonia. However, there is a lack of data to know whether the vaccine will also induce similar immunity in the mucosa (where the virus “sneaks” into the body).

Oropharyngeal secretions can detect the possible presence of a virus in the throat/©Adobe Stock.
Another type of antibody, IgA immunoglobulin, survives in the nose and throat and can “clear” the entry of respiratory viruses (such as SARS-CoV-2). If the virus colonizes the upper respiratory system, the pathogen can survive even if it does not cause a severe form of COVID-19. This is why it is so important to keep using masks, wash your hands, keep your distance and ventilate, so as to minimize the risk that your nose will continue to be a source of infection for other people.
inside Animal research The nasal passages also have no protective measures against viral infections, which suggests that transmission may continue. Allegedly, although the viral load is lower than that of unvaccinated primates, the pathogen survives in the noses of vaccinated non-human primates and is subsequently exposed to the virus. Preclinical studies modern.
He warned: “We don’t know how many viruses can be transmitted.” Beatrice Moss, Is an expert in the infectious disease service department and one of the researchers conducting the Janssen vaccine clinical trial at the German Trias i Pujol Hospital in Badalona. He added: “In addition, we have no information about the immunity of the vaccine against the new variant.”
Zúñiga pointed out that Preliminary data Vaccinations IsraelCountries with the most advanced immunization programs indicate that the spread of the virus is decreasing, although it is still unknown whether vaccines can prevent infection. He explained cautiously: “One possible explanation is that the viral load is low and you are unlikely to be infected, although it is not yet clear.”
Vaccination prioritizes the elderly and the disadvantaged
The vaccines currently approved in Europe-as of March 17 for Pfizer-BioNTech, Oxford-AstraZeneca, Oxford University, Moderna and Janssen vaccines, were performed in the arm through two punctures, less than a month apart. Zuniga said: “Intramuscular vaccines are not the most suitable vaccine for inducing mucosal immunity and IgA production.” Experts added that vaccines for intranasal and oral administration require longer development time than current vaccines.
As in many other countries, in Spain, vaccination strategies prioritize vulnerable groups and the elderly, as age is the main risk factor for hospitalization and death. The reason for vaccinating priority groups is that, for example, large numbers of residents in elderly centers and non-institutionalized families are vaccinated to protect them from the most serious form of covid-19.
In short, a vaccine against covid-19 can prevent the most serious diseases. The goal is to reduce the mortality rate of the virus and prevent the health system from collapsing. Therefore, even if someone is vaccinated, they must continue to maintain all protective measures.
.