The World Health Organization (WHO) says it currently recommends administering the same type of vaccine for both doses, but this may be subject to change as further research is done.
This comes after coordinating minister for the vaccine rollout Khairy Jamaluddin said the government was looking into the possibility of using the AstraZeneca vaccine for the first dose and Pfizer for the second, following research conducted in Europe that indicated such a regime might bring better immunity among recipients.
“The Covid-19 vaccines with WHO Emergency Use Listing (EUL) have only been assessed as single product regimens,” said Dr Jacqueline Lo, WHO representative to Malaysia, Brunei Darussalam and Singapore.
Both Pfizer and AstraZeneca’s products have been approved through this review process.
Of the other vaccines Malaysia has secured deals to procure, Sinovac has received similar authorisation from WHO while jabs from CanSino and Russia’s Sputnik V are under review by the world body.
“Given the limited data, it is currently recommended to administer the same product for the second dose. We will provide more guidance as more data becomes available.”
However, Lo said the organisation encouraged and welcomed further study into combining different products.
“Having the option to ‘mix and match’ has the potential to allow for flexibility in logistics and scheduling among Covid-19 vaccines.”
She noted that an ongoing trial, helmed by the University of Oxford, which initially started to investigate mixing the AstraZeneca and Pfizer vaccines, has recently expanded to include vaccines from Moderna and Novavax.
Similar projects have been undertaken in Germany and Spain, which suggest using the AstraZeneca vaccine as the first dose and Pfizer’s as their second dose to produce a more robust immune response. – FMT