BENGALURU: Experts within Karnataka and outside say that in routine immunisation, booster doses are usually of the same vaccine brand as given earlier, unless availability is an issue. The same is being advised to the government for Covid-19 vaccination booster shots.
Karnataka on Sunday announced that it will be rolling out vaccine booster shots for healthcare workers, frontline workers, those above 60 years and people with comorbidities, on January 10.
In addition to this, vaccination for children aged between 15 and 18 years will be launched on January 3. It is estimated that there are 43 lakh children eligible to take the vaccine in the state.
“We have shared with the government that generally, booster shots in immunisation are of the same brand as that given to the beneficiary earlier, as opposed to mixing. A majority of Indians have taken Covishield and the production and supply of Covaxin is much less. It may not suffice for all beneficiaries who have taken two doses of Covishield,” said a doctor who is an adviser to the state government.
In addition to this, experts point out that Covaxin may be now diverted for the paediatric population.
For vaccination against diseases such as typhoid and rabies, booster doses are of the same brand as administered earlier, as they have the same antigenic components, they said.
The brand is usually changed due to unavailability, and if there is an existing risk.
Agreeing with this, Dr. T Jacob John, retired professor and Head of the Department of Virology at Christian Medical College, Vellore, said there are a few studies and research which show that crossover vaccines show better results but we don’t have any Indian data available on this.
“Hence, it may be safe to use the same vaccine as used previously. However, if we have to crossover, then it would be better to use WHO-recommended vaccines only. Since Sputnik is not recommended by them, it would be ideal to use the safest vaccine, which is Covaxin. Those who have already taken Covishield, Covaxin and Sputnik, can opt for a Covaxin booster,” said Dr. John.
A member of the Covid-19 Technical Advisory Committee said studies on using the same and different boosters are ongoing, and results are expected in a few weeks.
The evidence available from abroad until now shows that both options have resulted in good immunogenic responses, the doctor said.
Karnataka Health Commissioner Randeep D said the state is awaiting directions from the Centre on the combination of booster doses, and supply will be in line with the same.
‘Centre must ensure Covaxin stocks
The Indian Medical Association (IMA) on Sunday said the Centre should ensure large-scale availability of Covaxin if a mix-match policy is adopted for booster doses for healthcare workers, as a majority of people have taken Covishield as their first and second doses.
In a letter thanking the Prime Minister for the announcement of the precautionary booster dose of vaccination for healthcare workers, Dr. JA Jayalal, National President, IMA, said, “If the policy of additional dose with mix-match policy is adopted, the government should ensure availability of Covaxin.”
Meanwhile, the letter also stated that the vaccination process for children must be handled with much more care, and constant monitoring and surveillance must be ensured.
“Government should seek the cooperation of family doctors and paediatricians,’’ the letter stated.