Pfizer and its development partner BioNTech have said that they are working on a booster dose for their COVID-19 vaccine, with the aim of offering protection against new variants.
The news closely follows an announcement from Moderna, which also said that it would be testing an additional booster dose of its COVID-19 vaccine.
The aim of developing such booster doses is to determine if they could further increase the level of neutralising antibodies that fight against emerging strains.
“Every time a new variant comes up we should be able to test whether or not [our vaccine] is effective,” Pfizer chief executive officer Albert Bourla told Bloomberg.
“Once we discover something that it is not as effective, we will very, very quickly be able to produce a booster dose that will be a small variation to the current vaccine,” he added.
Last week, Pfizer/BioNTech published new results from a laboratory study of their COVID-19 vaccine, which found that the jab is likely to protect against the new coronavirus strain discovered in the UK.
Data from this study found that participants who had received the vaccine were able to produce antibodies that neutralised the new virus strain, meaning that “it is very unlikely that the UK variant viruses will escape BNT162b2-mediated protection”.
On Tuesday Moderna said that its vaccine appears to be effective against the UK variant, and also the new strain discovered in South Africa (SA).
Results from in vitro studies found that vaccination with its COVID-19 vaccine produced neutralising antibodies against both the UK and SA variants, known as B.1.1.7 and B.1.351 respectively.
In this early laboratory study, researchers observed no significant impact on antibodies with the UK variant, relative to prior variants.
However, Moderna noted that there was a six-fold reduction in neutralising antibodies observed with the B.1.351 strain, although the company added that the levels induced by its vaccine should still offer protection.
BioNTech is also planning to publish an additional analysis of its Pifzer-partnered vaccine’s efficacy against the coronavirus strain identified in South Africa.
Bourla also told Bloomberg that people may require a one-shot annual COVID-19 vaccine, which would be developed against whichever strain is predicted to circulate each year.
“We need to be very vigilant about the strains that exist and very vigilant about vaccinating people,” he added.