Estonia will only use mRNA coronavirus vaccines for booster doses regardless of the vaccine used for the initial vaccination process.
The Estonian immunoprophylaxis committee has approved two vaccines for booster doses: Pfizer/BioNTech (Comirnaty) and Moderna. Pfizer was approved first, which is why most people who have received an additional dose of vaccine have received a Pfizer dose. Both of the approved vaccines will be used regardless of the vaccine used for the initial vaccination process.
Even if the person has completed the vaccination process with the Pfizer or Moderna vaccines, they can opt to get a booster dose with another vaccine.
Immunoprophylaxis committee member and government's scientific council head Irja Lutsar said that while the U.S. is trying to use the same vaccine for booster doses, Europe is looking at cross-vaccination.
"Mixing doses is not forbidden" Lutsar told ERR, adding that studies have shown cross-vaccinations to be very effective. In addition, the U.S. Centers for Disease Control and Prevention (CDC) announced on Friday that it will accept mixed-dose coronavirus vaccines from international travelers.
"Take what you are given. They are pretty much equal," Lutsar said.
Since the vaccine doses differ from one another, people will get a full dose of the Pfizer for a booster dose or a half-dose of Moderna. The single volume of a Pfizer vaccine dose is 30 micrograms, but 100 micrograms for Moderna.
"There is more of the Moderna vaccine in the vial and booster doses are supplemental, which is why there is no need for as many antibodies as in the start. It is also quite logical that the higher the concentration, the more there are antibodies and side effects," Lutsar commented on the Moderna vaccine.
Approval for child vaccinations can come in December
The Pfizer vaccine has already been approved for use for children aged 6-11 in the U.S. The European Medicines Agency will likely discuss the option in December. Lutsar said Estonia will make its respective decision as soon as the vaccine is approved for child vaccinations in Europe.
Pfizer's vaccine volume for children is 10 micrograms.
A decision is also expected on supplemental doses for people inoculated with the Janssen vaccine, since its efficacy has proven itself to be lower than other vaccines. "Janssen likely is not a one-dose vaccine, another booster dose will have to be done," Lutsar said.
As of Monday morning, 82,223 people have received an additional or booster dose.
Editor: Kristjan Kallaste