Time not ripe for Covid vaccine combos: Experts

As vaccination remains the key in the fight against Covid, many are exploring the option of mixing and matching vaccines to build a stronger immune response.

Published: 07th August 2021 06:29 AM  |   Last Updated: 07th August 2021 06:29 AM   |  A+A-

Covid Vaccine, Coronavirus

For representational purpose. (File Photo | AFP)

Express News Service

KOCHI: As vaccination remains the key in the fight against Covid, many are exploring the option of mixing and matching vaccines to build a stronger immune response. According to doctors, many preparing to travel overseas are seeking to know the viability of taking two different vaccines, including Pfizer and Moderna.

Given that restrictions on international flights are expected to be lifted soon, as the United Arab Emirates (UAE) has done already, many are preparing to return to their jobs abroad and are looking at various methods and best combo of vaccines that will keep the infection at bay. “People travelling abroad including the UK and UAE are inquiring about the mix and match technique. Since they can access more vaccines abroad, they are exploring the ways. Though studies conducted across the world reveal that it is effective, there is no definite conclusion drawn out,” said a Kerala-based epidemiologist.

Studies conducted across the world reveal that combining two different vaccines could be effective as it offers more immune response. Recently, the British study confirmed that a combination of AstraZeneca (Covishield) and Pfizer-BioNTech vaccines triggers a higher number of antibodies compared to just two doses of Covishield.

In some countries, due to the perception of increased risk of blood clots, especially among the elderly, the use of AstraZeneca was limited and quite a few people who received their first dose of AstraZeneca had to take Pfizer or Moderna as their second dose. The result of the combination was surprising as it produced better immune response.

However, since there is not enough information to suggest the reason for the combinations to be more effective, experts advise to follow the traditional vaccination schedule.“We have a plethora of studies coming up suggesting that taking two different kinds of Covid vaccines in sequence could generate a higher immune response than the regular vaccination. But, we need to understand that the real-world benefits of this enhanced immunogenicity have to be balanced against the very real threat of immune-related adverse effects.

So until long-term large population data is available, it is best to stick to the traditional vaccination schedule. In immune- suppressed where primary vaccination schedules are proven to be less effective, this strategy could be considered,” said Dr Anup R Warrier, Infectious Disease expert. Meanwhile, there has been a demand among healthcare workers to provide booster doses of vaccines as they are more susceptible to Covid infection. “More and more staff are getting re-infected even after being fully vaccinated. Doctors and medical staff, including house surgeons working in ICUs, are getting re-infected. The government should consider providing booster doses to health workers,” said Ashik K, a house surgeon based in Kochi.


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