European health agencies have said the fourth dose of COVID-19 mRNA vaccination, also known as the second booster shot, is currently only considered for people who are immunocompromised or over the age of 80.
The European Medical Agency’s COVID-19 Task Force (ETF) and the European Center for Disease Prevention and Control (ECDC) published their joint position on the current need for fourth doses on Wednesday 6 April.
The statement is based on currently available epidemiological studies and data.
Early data from Israel, which began rolling out fourth doses of the vaccine in January, indicated that the risk of serious infection and/or death from COVID-19 is reduced for up to 10 weeks after the outbreak. administration of a fourth dose compared to those who only received the third dose.
Although there are “still limited data” on the waning rate of protection after the first booster dose in adults over 80, the agencies said that “due to the frailty of this population, the response lower immune response to vaccination and higher risk of severe COVID-19, a second booster could be given,” the ECDC press release said.
It should be noted that safety and efficacy data “are only available for a fourth dose given at least four months after a third dose, and this interval, together with local epidemiological data, should be taken into account when of the choice of vaccination strategies”.
Fourth dose for immunocompromised
For the immunocompromised, the the administration of a fourth dose of mRNA vaccine is already recommended and should be part of ongoing vaccination campaigns in the EU.
This is based on data received from Israel, which showed that the fourth dose of an mRNA vaccine given to immunocompromised people at least four months after the third dose is able to restore immunity to the level seen after the third dose without increasing safety. concerns.
Immunogenicity data are available for a three-week follow-up period, and they indicate that protection against the Omicron variant may decline at a rate similar to that observed when a third dose was administered.
Only preliminary data is currently available regarding the efficacy of the vaccine against serious illnesses after a fourth dose, which means that longer-term data on the duration of antibody levels achieved have yet to emerge.
There are no data regarding additional supplemental doses in this population. However, the ECDC press release stated that “in severely immunocompromised subjects, passive immunization with monoclonal antibodies should be considered as an additional shield to protect against infection and disease”.
No fourth shot for those under 80 – yet
As for people aged 60 to 80, “there is no indication of an imminent need for a second booster dose”, as there is currently no clear epidemiological signal from the European region of the decrease substantial vaccine protection against severe COVID-19. 19.
However, officials stressed that the situation should be monitored in case “an increased risk of severe COVID-19 emerges in vaccinated persons”. In this case, the fourth dose “may be considered” in this age group.
And with regard to those under 60, the ECDC and ETF said the need for a second booster dose is “not supported by available data on the continued level of vaccine protection against diseases serious or death”.
From Tuesday, twenty countries recommend the fourth dose for immunocompromised people.
In the meantime, nine countries, such as France, Germany, Greece and Hungary, recommend a second booster dose for different vulnerable population groups such as residents of long-term care facilities and the elderly, with different age thresholds.
The statement also highlighted the importance of planning catch-up and revaccination campaigns seasonally, as “it is known that respiratory viruses tend to spread more consistently during the cold season.”
[Edited by Nathalie Weatherald]