Nearly a year after the rollout of COVID-19 vaccines for health-care workers, the primary vaccination schedule to cover 75 million teenagers aged 15-17 years began across the country on January 3. Nearly 0.4 million children received the first dose on the first day. With all adults aged 18 years and above already being covered, the inclusion of teenagers has reduced the eligibility age group to 15 years. The decision to vaccinate teenagers, which was announced by Prime Minister Narendra Modi on December 25 last year, was based on the emergence of the highly transmissive Omicron variant, its spread to many countries in about a month after it was designated as a variant of concern, the global case surge, and the trend in many developed countries of vaccinating adolescents and children. While there is no clear consensus on whether healthy teenagers above 15 should be vaccinated particularly as severe disease and deaths in this age group are relatively low when infected by the virus and a significant percentage of teenagers and children have been already infected as indicated by a few sero surveys, vaccination does increase the level of protection. Unlike in the case of adults who were vaccinated with one of the two vaccines — Covishield or Covaxin — teenagers will be administered only Covaxin. It was found to be safe and immunogenic in teenagers during a phase-2/3 of the clinical trial; only 175 adolescents aged 12 to 18 years were studied. The data of the trial, yet to be peer-reviewed, were posted on a preprint server on December 29. As in the case of adults, the eligible teenagers will receive the second dose 28 days after the first.
Besides providing teenagers with a primary vaccine, health-care and frontline workers and those above 60 years with co-morbidities will be provided with a precaution dose. Providing Covaxin as the precaution dose to all the people who have received the same vaccine as part of the primary vaccination schedule, scientifically called as homologous vaccine booster, will be the best approach at least till there is evidence on using a different vaccine as a booster shot. Though Covaxin accounts for only around 10% of all doses administered till date, the scientific bodies need to factor in vaccine availability too. This becomes particularly important as only Covaxin is used for vaccinating teenagers and its production is very limited in comparison to Covishield. The compulsion to test other vaccines that can be used in place of Covaxin as an additional dose in adults is therefore overwhelming. The approval of two additional vaccines, which are manufactured using different vaccine platforms, will further lessen the reliance on Covaxin for primary vaccination of adults, thus ensuring that the vaccination programme for teenagers does not suffer from shortages midway.