Can you mix and match Covid-19 vaccines?

Published June 17, 2021
Medical staffers from Taiwan’s vaccine maker Medigen Vaccine Biologics Crop (MVC) work at a lab in Hsinchu on June 17. — AFP
Medical staffers from Taiwan’s vaccine maker Medigen Vaccine Biologics Crop (MVC) work at a lab in Hsinchu on June 17. — AFP

Can you mix and match two-dose Covid-19 vaccines? It's likely safe and effective, but researchers are still gathering data to be sure.

The authorised Covid-19 shots around the world are all designed to stimulate your immune system to produce virus-fighting antibodies, though the way they do so varies, noted Dr Kate O' Brien, director of the World Health Organisation's vaccine unit.

"Based on the basic principles of how vaccines work, we do think that the mix-and-match regimens are going to work," she said.

Scientists at Oxford University in the United Kingdom are testing combinations of the two-dose Covid-19 vaccines made by AstraZeneca, Moderna, Novavax and Pfizer-BioNTech. Smaller trials are also ongoing in Spain and Germany.

"We really just need to get the evidence in each of these (vaccine) combinations," OBrien said.

Read more: All you need to know about Covid vaccines in Pakistan

So far, limited data suggests an AstraZeneca shot followed by the Pfizer shot is safe and effective. The combination also appears to come with a slightly higher likelihood of temporary side effects like aches and chills.

"That might be because mixing and matching different types of vaccines can often produce a stronger immune response," said Lawrence Young, a virologist at the University of Warwick in the United Kingdom.

In some places, health officials already suggest mixing in select circumstances.

After the AstraZeneca vaccine was linked to extremely rare blood clots, many European countries including Germany, France and Spain recommended people who got it as a first dose get a Pfizer or Moderna shot as a second dose instead.

In Britain and Canada, officials say people should aim to get the same vaccine for their second dose if possible. If they got AstraZeneca as their first shot, they're advised to get another vaccine only if they have a history of blood clots or other conditions that might put them at higher risk of clots.

Opinion

Editorial

Afghan turbulence
Updated 19 Mar, 2024

Afghan turbulence

RELATIONS between the newly formed government and Afghanistan’s de facto Taliban rulers have begun on an...
In disarray
19 Mar, 2024

In disarray

IT is clear that there is some bad blood within the PTI’s ranks. Ever since the PTI lost a key battle over ...
Festering wound
19 Mar, 2024

Festering wound

PROTESTS unfolded once more in Gwadar, this time against the alleged enforced disappearances of two young men, who...
Defining extremism
Updated 18 Mar, 2024

Defining extremism

Redefining extremism may well be the first step to clamping down on advocacy for Palestine.
Climate in focus
18 Mar, 2024

Climate in focus

IN a welcome order by the Supreme Court, the new government has been tasked with providing a report on actions taken...
Growing rabies concern
18 Mar, 2024

Growing rabies concern

DOG-BITE is an old problem in Pakistan. Amid a surfeit of public health challenges, rabies now seems poised to ...