With the approval of Corbevax as a booster dose, India will have a heterologous shot

With the approval of Corbevax as a booster dose, India will have a heterologous shot

• The Indian drug regulator has given greenlight to Corbevax as a booster dose for all adults above 18 years who have received two doses of either Covishield or Covaxin as part of primary vacci­nation, a heterologous booster shot has come a step closer to being administered to people.
• The vaccine was developed by Hyderabad-based Biological E. Limited (BE)’s.
• Though booster shots have been administered since January 10 begin­ning with health care and frontline workers, and peo­ple over 60 with comorbidities, India has been using the same vaccine for both primary vaccination and booster (homologous boosting).
• In clinical trials, a booster dose using a vaccine that is different from the one used for primary vaccination — technically called heterologous boosting — produced higher immune res­ponses when compared with a same vaccine for prim­ary and booster vaccination.
• However, the trial has thus only shown that Corbevax as a heterologous booster increas­es the immune responses but failed to show that hetero­logous boosting with this vaccine produces superior immune responses than homologous boosting with Covishield or Covaxin.