PT  - JOURNAL ARTICLE
AU  - Houssein H Ayoub
AU  - Hiam Chemaitelly
AU  - Monia Makhoul
AU  - Zaina Al Kanaani
AU  - Einas Al Kuwari
AU  - Adeel A Butt
AU  - Peter Coyle
AU  - Andrew Jeremijenko
AU  - Anvar Hassan Kaleeckal
AU  - Ali Nizar Latif
AU  - Riyazuddin Mohammad Shaik
AU  - Hanan F Abdul Rahim
AU  - Gheyath K Nasrallah
AU  - Hadi M Yassine
AU  - Mohamed G Al Kuwari
AU  - Hamad Eid Al Romaihi
AU  - Mohamed H Al-Thani
AU  - Roberto Bertollini
AU  - Abdullatif Al Khal
AU  - Laith J Abu-Raddad
TI  - Epidemiological impact of prioritising SARS-CoV-2 vaccination by antibody status: mathematical modelling analyses
AID  - 10.1136/bmjinnov-2021-000677
DP  - 2021 Apr 01
TA  - BMJ Innovations
PG  - 327--336
VI  - 7
IP  - 2
4099  - http://innovations.bmj.com/content/7/2/327.short
4100  - http://innovations.bmj.com/content/7/2/327.full
SO  - BMJ Innov2021 Apr 01; 7
AB  - Background Vaccines against SARS-CoV-2 have been developed, but their availability falls far short of global needs. This study aimed to investigate the impact of prioritising available doses on the basis of recipient antibody status, that is by exposure status, using Qatar as an example.Methods Vaccination impact (defined as the reduction in infection incidence and the number of vaccinations needed to avert one infection or one adverse disease outcome) was assessed under different scale-up scenarios using a deterministic meta-population mathematical model describing SARS-CoV-2 transmission and disease progression in the presence of vaccination.Results For a vaccine that protects against infection with an efficacy of 95%, half as many vaccinations were needed to avert one infection, disease outcome or death by prioritising antibody-negative individuals for vaccination. Prioritisation by antibody status reduced incidence at a faster rate and led to faster elimination of infection and return to normalcy. Further prioritisation by age group amplified the gains of prioritisation by antibody status. Gains from prioritisation by antibody status were largest in settings where the proportion of the population already infected at the commencement of vaccination was 30%–60%. For a vaccine that only protects against disease and not infection, vaccine impact was reduced by half, whether this impact was measured in terms of averted infections or disease outcomes, but the relative gains from using antibody status to prioritise vaccination recipients were similar.Conclusions Major health and economic gains can be achieved more quickly by prioritizing those who are antibody-negative while doses of the vaccine remain in short supply.All data relevant to the study are included in the article or uploaded as supplemental information.