Research by experts from Qatar Foundation has produced consistent evidence from vaccinated groups that vaccine effectiveness against mild infection is gradually waning in the months after the second dose.

However, there is no waning in vaccine effectiveness against COVID-19 hospitalisation and death, which remained robust for six months after the second dose.

While Qatar, the US, the UK, and Germany set out plans to begin booster vaccination, no definite decision has yet been taken in most of the countries in the Arab region.

According to Dr Laith Abu-Raddad, Professor of Population Health Sciences at Weill Cornell Medicine-Qatar (WCM-Q), there is a decrease in immunity after the second vaccination dose and more data is emerging about the effectiveness of adding a third booster vaccination jab. WCM-Q is a partner university of Qatar Foundation where research into lasting vaccine effectiveness has been conducted. Dr Abu-Raddad is also an Adjunct Professor of Epidemiology and Biostatistics at Hamad Bin Khalifa University (HBKU).

Third jab vs vaccinating the unvaccinated

Scientists continue to debate whether adding the booster jab is a more effective solution than focusing on vaccinating those who remain unvaccinated. Dr Abu-Raddad emphasised that we need to do both for optimal protection and for the global community to return to a sense of normality beyond the constraints of the COVID-19 pandemic.

The results we have from our research so far are consistent with the previous statement of vaccine developers that antibodies are gradually waning after the second dose, and that the immune response is robust after the third booster jab and is adding even more protection against infection than the second dose.

Some studies indicate mixing vaccine types may also be beneficial

On mixing and matching COVID-19 vaccines or boosters, Dr Abu-Raddad explained that some studies indicated that this can be effective, but the evidence is still not fully sufficient to move in this direction. Booster jabs will be of the same vaccine used in the first and second doses, but this may change over the coming weeks when sufficient data is available regarding the efficacy of mixing vaccine types.

Will booster vaccination exacerbate existing vaccine inequity?

In countries such as Lebanon, Jordan, Kuwait, and Tunisia, the average percentage of fully vaccinated people is only 28%. And while some experts debate the potential of increasing this vaccine inequity by adding a vaccine booster, Dr Abu-Raddad believes the solution to this inequity is increasing the production of vaccines as well as improving vaccine distribution infrastructure.

He said that the US is planning to donate a billion doses to people around the world, while also providing booster vaccinations to Americans. He added that more countries need to move in this direction.

Qatar is one of the countries in the Arab region planning to start implementing the distribution of booster shots among its residents, beginning with its high-risk population.

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