Vaccine developers are examining whether the addition of a third dose might offer added protection against emerging SARS-CoV-2 variants, CNN reports. They are also working on modified versions of their vaccines, it adds.
Pfizer CEO Albert Bourla tells NBC News that they suspect another dose of their vaccine will increase immune response. "We believe that the third dose will raise the antibody response 10- to 20- fold," he says.
NBC News adds that they are conducting a new study in which they will examine the safety and efficacy of a third dose of the Pfizer-BioNTech vaccine among individuals between 18 to 55 and between 65 to 85. Meanwhile, Pfizer is also planning to test a modified version of its vaccine to see how it fares against the SARS-CoV-2 variant B.1.351 first uncovered in South Africa.
Similarly, CNBC reports that Moderna is beginning a clinical trial of a modified version of its vaccine, dubbed mRNA-1273.351, to gauge how well it may protect against the B.1.351 variant. "Moderna is committed to making as many updates to our vaccine as necessary until the pandemic is under control," CEO Stephane Bancel, says in a statement.
CNN adds that Moderna is also testing whether a third, though lower dose, of its original SARS-CoV-2 vaccine increases immunity against new variants.