The school stated that the emergence of Covid-19 variants and the decrease in vaccine-induced immune response within a few months after vaccination have suggested the potential need for booster vaccination in the near future.

It also stated that so far there is only very limited data on the safety of a booster dose, so there is an urgent need to conduct this research to help scientists design better vaccine deployment strategies against the emerging variants.

Volunteers should be 30 years old or above, and have received two doses of Covid-19 vaccines, including Sinovac or Sinopharm, 90 days ago. They should also be willing to provide blood samples.

But those who are pregnant, have allergies to the ingredients of mRNA vaccines, or have been previously infected with Covid-19 cannot join the scheme.

The school will offer tympanic thermometers or supermarket coupons to volunteers during each regular follow-up when they have their samples collected.

They will also be sent results of laboratory testing and findings of the study.