The mixing of two vaccines is known as vaccine mixing or vaccine cocktail. Presently in India, all the approved vaccines of Covid-19 available are of two doses. The first Covid-19 vaccine is known as the “prime dose”, it prepares the human immune system to build antibodies. The second dose is called the “booster dose”. With this, the immune system receives the boost to produce a large number of antibodies.
But presently in some countries, the vaccine cocktail is being seen as an option. However, vaccine mixing has not started in India yet. The Union Health Ministry has clarified that the research for vaccine mixing is in process, and in India, the vaccine will not be mixed until the research is completed.
Regarding vaccine mixing, NITI Aayog’s member Dr. VK Paul said,”It is scientifically possible to do so but practical use is yet to be done. A recent UK study has found that it is safe to mix doses of different types of vaccines, but there will be various effects, the study has revealed. But there needs to be more research on the same. It can’t be said definitively that mixing of doses can be practiced but there is no robust scientific evidence as of now. Only time will tell whether it will be done in the future or not. It will depend on international studies, World Health Organization findings, etc. Our experts are also continuously studying.”
What happens if the vaccine is mixed?
Presently, UK’s Oxford Vaccine Group is conducting the ‘mix and match’ trial to study the combination of a Pfizer or Covishield first dose followed by a Moderna or Novavax second dose. The trial has been underway with at least 800 volunteers, all of them over 50 years of age.
According to a letter from the researchers published in “The Lancet”, shows the combination of Covishield and Pfizer is likely to produce a stronger immediate physical reaction — soreness or swelling at the site of injection, fever and headaches — after the second dose than two doses of the same vaccine. But these reactions were not severe or long-lasting and there were no other safety concerns. However, it’s unclear if the combination affects efficacy. More data is expected later this month.
The genesis of vaccine cocktail
Actually, vaccine mixing is not new, the mixing of different types of vaccines is technically called ‘heterologous prime-boost’. It was introduced in the 1990s by HIV researchers as a testing strategy. Scientifically, this is nothing new, says Dr. Pierre Mullian, executive director of the Innovative Medicine Initiative (IMI).
No shortage of vaccine in the country
A grouping number of countries have started vaccine mixing amid the shortage of vaccine, so that the vaccine reaches to the maximum number of people. Presently, vaccine cocktail is being given in Canada, China, Finland, France, Norway, Russia, South Korea, Spain, Sweden, and the UK.
Regarding India, ICMR Director General Dr. Balram Bhargava says that there is no shortage of corona vaccine in India. By mid-July or August, we will have enough doses to vaccinate 10 million people daily. It is expected that by December the entire population will be vaccinated.