At the moment there are insufficient data to support the administration of a fourth dose of the mRNA vaccine -Pfizer/BioNTech or Moderna- against the covid-19 virus in the general population, although both the European Medicines Agency (EMA) as the European Center for the Control and Prevention of Infectious Diseases (ECDC) agree that it can be administered to older than 80 years due to the higher risk of severe covid in this age group.
Under the new recommendation, there is currently no clear evidence that the vaccine’s protection against severe forms of disease is being substantially diminished in adults ages 60-79 with normal immune systems and, therefore, “there is no clear evidence to support the immediate use of a second booster dose & rdquor; although both organizations will continue to monitor the situation in case the epidemiological situation changes.
At the moment, there is also no conclusive evidence that the vaccine’s protection against severe disease is diminishing or that the fourth dose is of added value for under 60 years of age with normal immune systems. All evidence on the fourth dose comes from Israel where data indicate that a second booster dose given at least 4 months after the first restores antibody levels without raising new safety concerns. Data also suggest that a second booster dose provides additional protection against severe illness, although the duration of benefit is unknown and the evidence is still limited.
64% of Europeans with a booster
Until the end of March, 83% of adults in the EU had received the full course of vaccination but only 64% had received a booster dose. Hence the insistence to all those who have not completed the initial vaccination or who have not received the booster dose to do so as soon as possible. From here, and given that the revaccination campaigns could begin in the fall, the authorities will have to study the best time to apply additional doses, possibly taking advantage of the updated vaccines. According to the EMA and the ECDC, when deciding on future booster dosesEU health authorities must take into account factors such as the spread of the infection, the effects of covid-19 on different populations and the appearance of new variants.