US pharmaceutical company Pfizer is seeking approval for a third vaccine ‘booster’ dose, which it says can give up to ten times more protection.
An ongoing booster trial by Pfizer and BioNTech provided “encouraging data” showing that a third dose, given six to eight months after the second dose, can increase the antibody count five to ten times compared to the levels after the original doses, whilst prolonging and strengthening protection.
“The companies expect to publish more definitive data soon as well as in a peer-reviewed journal and plan to submit the data to the US Food and Drug administrations, the European Medicines Agency (EMA) and other regulatory authorities in the coming weeks,” a press release stated.
In the meantime, they are working on an updated version of the vaccine against the more infectious Delta variant, which is now the dominant strain in Belgium and is causing a sharp rise in the number of new infections.
Just 10 to 20 subjects took part in the booster trial, however “the data are so clear that we are completely confident that the full study will confirm them,” according to Pfizer principal investigator Mikael Dolsten, who added that the results were published now because “there is a great deal of concern about the Delta variant”.
Although preventing serious illness remains high, the vaccine’s efficacy in preventing both infection and symptomatic disease can decline six months post-vaccination, as seen in real-world data released from the Israel Ministry of Health, which also showed that the Pfizer vaccine offers just 64% protection against the Delta variant.
However, most people in Israel were vaccinated at the start of the year, which could mean that the levels of antibodies dropping six months after vaccination could play a part in the reduced efficacy.
Meanwhile, the Pfizer vaccine would still provide 93% protection against serious illness, hospitalisation and death.
Booster strategy in Belgium
In Belgium, the Vaccination Taskforce has already developed a blueprint in case a third shot of the corona vaccine is needed in autumn, according to reports from De Morgen.
By that time, the entire population in the age groups that can be vaccinated, starting from 12 years old, should have been given the option to get a coronavirus vaccine, and the task force has already started to analyse what should be done in the following phase.
Although a decision still has to be made by EMA before EU Member States can start administering third doses, Belgium wants to be ready for this scenario.
The plan, which includes scenarios about who is eligible, how many vaccines will be needed and whether they should be administered in vaccination centres, will help avoid chaos if the booster shot is approved.