The delta variant has become the dominant variant in several countries, including India and the United Kingdom. Some reports suggest that existing COVID-19 vaccines may not be as effective as thought in preventing infection with Delta.
The concept of booster vaccines is to prolong protective immunity, particularly if there is evidence that protection is fading after some time.
According to Pfizer’s 2021 analysis, receiving an additional booster dose of their COVID-19 vaccine after having the first two doses increases the amount of Delta variant antibodies five times more in 18-to-55-year-olds.
This third dose would be identical to the two doses of the currently authorized Pfizer vaccine. However, researchers are discovering an “updated” vaccine dose, adapted to target the Delta variant specifically.
A Pfizer spokesperson “The ongoing booster trial is evaluating the sufficiency and safety of the current BNT162b2 vaccine. While we believe the third dose of BNT162b2 has the potential to preserve the highest levels of protective efficacy against all currently known variants, including Delta, we are remaining alert and are also developing an updated version of the vaccine that targets the Delta variant significantly.”
Following these findings, both Pfizer and Moderna have been seeking authorization for their booster shots from countries that have already authorized their main COVID-19 vaccines.