Booster Covid vaccine on the table

As highly contagious variants of the coronavirus continue to proliferate, talk of a third dose of the vaccine, starting with specific groups, is gaining momentum. 

More specifically, experts of Greece’s National Vaccination Committee are expected within August to reach a conclusion regarding the timing of a booster shot of the vaccine against Covid-19. For their part, pharmaceutical companies have said a third dose must be administered at least six months after the completion of vaccination.

Discussions about a booster dose intensified last month when scientists at Pfizer and BioNTech reported that a booster six months after its second and final dose enhances protection against Covid-19.

The relevant data so far suggests a third dose will be needed as a priority for people with a reduced immune response to the vaccine, due to diseases that have led to transplants and to immunosuppressive treatment, or age. Also among the first groups that will receive the third dose are health workers, the majority of whom got the vaccine seven months ago.

According to Maria Theodoridou, emeritus professor of pediatrics and chair of the National Vaccination Committee, the timing of a third dose will depend mainly on the data regarding the duration of immunity. 

“It seems that for people who do not have underlying diseases or belong to special categories, the duration of immunity exceeds six months, which was considered from the beginning as a possible time to think about a third dose,” she said. However, she noted that “there is no specific time to say when we will start administering a third dose, nor has a list been drawn up” of those who will be in front of the line.

Nonetheless, speaking to Kathimerini, the president of the Association of Athens and Piraeus Hospital Doctors, Matina Pagoni said “we are waiting for the [European] Commission to inform us in August about when the third dose will be given to the health workers.” 

A noteworthy development cited by Pagoni is that there have been mild cases of the disease among vaccinated health workers during the recent surge. “Vaccine efficacy is around 90%, which means that these cases belong to the other 10% and are the result of the very high viral load observed at this time,” she said.