Can You Mix-and-Match COVID-19 Vaccines For Better Immunity?

As robust vaccination programs are underway to counter the COVID-19 threat, there are more rumours than facts about the efficacy of the jab.  

Dr Rahul Pandit, Director-Critical Care, Fortis Hospitals Mumbai and member of Maharashtra’s COVID19 Taskforce says, "Vaccination against COVID-19 is a subject dogged by several debates. Initially, people were sceptical about getting the vaccination, then there were speculations about which vaccine is better, then came the availability confusion and now there are several theories brewing around mixing different COVID-19 vaccines. But it is important that people do not get carried away with misinformation and keep faith in medical science."

The burning question at the moment is- Can you mix-and-match covid-19 vaccines for better immunity?

EVIDENCE FROM AROUND THE WORLD BRINGS HOPE

Dr Pandit says that some preliminary studies from Spain and UK indicated that vaccinating people with both the Oxford–AstraZeneca and Pfizer–BioNTech COVID-19 vaccines produces a potent immune response against the virus SARS-CoV2.

A trial of more than 600 people announced in an online presentation on 18 May 2021 was the first to show the benefits of combining different Coronavirus vaccines. Another study conducted by the University of Oxford, the Office of National Statistics (ONS) and the Department for Health and Social Care (DHSC) stated promising medical outcomes on mixing vaccines. This study was particularly based on understanding the impact of vaccination on antibody responses and new infections in a large group of adults from the general population aged 16years and older.

This study revealed that 21 days after a single dose of either Oxford-AstraZeneca or Pfizer-BioNTech vaccines (with no second dose), the rates of all new COVID19 infections had dropped by 65 per cent, symptomatic infections by 72per cent and infections without reported symptoms by 57 per cent.

This is good evidence as this study involved analysis of 1,610,562 test results from the nose and throat swabs taken from 373,402 study participants between 1 December 2020 and 3 April 2021. Similarly, another study published in the medRxiv* also highlighted that the vaccines also appeared to reduce the risk of contagion. These studies highlighted that mixing and cocktailing of vaccines help in achieving the desired immunity among people and that it covers most variants of concerns (VOC).

THE INDIAN CONTEXT: EVIDENCE YET TO BE GATHERED

While research from other parts of the world seems promising, Indian researchers are yet to find more evidence for the country.

Dr Pandit says, "It is yet to be seen if scientists and researchers, will begin trials to test the safety of different vaccines (which currently have emergency use authorization in the country). Going forward the trials may also include jabs that are in the pipeline. However, we do not need to hold back our vaccination till these studies are published; take the vaccine when it is your turn."

DO NOT BELIEVE IN RUMORS; SPEAK TO YOUR DOCTOR.

He adds that while the research is underway on the mixing of vaccines, the possibility of a positive effect is plausible, but a harmful reaction cannot be ruled out either.

This unresolved scientific question will be settled in the days to come. There is no need for panic or unnecessary contemplation.  It is an unresolved scientific question and science will settle it. Dr Pandit says, "Do not believe in rumours and speak to your doctor to clear your doubts. Studies have proved that even a single dose of vaccine can provide immunity for up to 12 weeks. Register for your initial dose and for those who have already taken their first jab, wait until your turn for the second dose."