Pfizer/BioNTech has announced this week that they will seek regulatory approval on a third dose of their vaccine, for a so-called booster vaccine.
However, the World Health Organization (WHO) has said it was currently unclear whether booster vaccines will be necessary, until further data is needed.
“We don’t know whether booster vaccines will be needed to maintain protection against Covid-19 until additional data is collected, but the question is under consideration by researchers,” the WHO said.
“There is limited data available on how long protection from current Covid-19 vaccine doses lasts and whether an additional booster dose would be beneficial and for whom.”
Pfizer and BioNTech have said that due to drop-offs in efficacy seen in Israel after six months, they believe a third dose may be necessary within six to twelve months after full vaccination.
“While protection against severe disease remained high across the full six months, a decline in efficacy against symptomatic disease over time and the continued emergence of variants are expected,” a statement from the two companies read.