Amid more infectious Covid-19 variants reported across the globe, scientists are recommending a combination of vaccine which may offer longer immunity and protection against variants.
Soumya Swaminathan, the World Health Organization’s chief scientist says that combination of Covid-19 vaccines seems to be working well against variants. She said, “It seems to be working well, this concept of heterologous prime-boost. This opens up the opportunity for countries that have vaccinated people with one vaccine and now are waiting for the second dose they have run out of, to potentially be able to use a different platform vaccine.”
But, she said that early data from the UK, Spain and Germany suggest a “mix-and-match" regimen using two different types of vaccines generates more pain, fever and other minor side effects compared with two doses of the same inoculation, a report in Bloomberg said.
Swaminathan adds that the so-called heterologous prime-boost combinations appear to spur a more robust immune response, leading to higher levels of antibodies and the white blood cells that kill virus-infected cells.
Countries, meanwhile, have already started testing a combination of vaccines to speed up immunisation. Malaysia, for example is considering a combination of the AstraZeneca Plc and Pfizer-BioNTech shots and the government is trying to speed up immunizations to achieve population-level immunity by year-end, Science, Technology and Innovation Minister Khairy Jamaluddin said.
Need for Booster Shot?
Some countries and pharmaceutical officials prepare for Covid booster shots against virus variants. But, health officials say it’s too early to tell if they will be required.
“We do not have the information that’s necessary to make the recommendation on whether or not a booster will be needed," Swaminathan said.
Pointing to the fact that the science is still evolving, she said that call is premature as many countries have still not inoculated against Covid-19.
Covid booster shots are likely to be rolled out in UK to avoid another surge during the winters. Health Secretary Matt Hancock earlier said that seven different vaccines are being tested in volunteers in England in the world’s first booster study.
UK has already inoculated a large proportion of population than any other economy. However, it has postponed lifting Covid-19 restrictions amid scare of the delta variant, first detected in India.
More-transmissible variants of Covid-19 require higher antibody levels to prevent infection. It has prompted vaccine makers including Pfizer and Moderna to test if the tweaked versions of their existing shots will provide broader immunity.
The report added that one dose of Novavax’s variant-directed vaccine may provide sufficient protection against the beta strain in individuals previously immunized against Covid-19.
The existing US-approved vaccines work well enough to protect against beta, delta and two other strains that the WHO has designated as variants of concern.