Structural, Social, and Contextual factors influencing COVID-19 vaccine uptake: A qualitative methods study among Healthcare Workers and Older People in Uganda. (preprint)

Background: The COVID-19 vaccine rollout program in Uganda was launched in March 2021 with Healthcare Workers (HCWs), older persons (50 years and above), and persons with chronic conditions as priority groups for vaccination. To inform the vaccine rollout efforts, we set out to explore the social and structural factors that influenced the uptake of COVID-19 vaccines among HCWs and older people in Uganda. Methods Between September and October 2021, we conducted 33 in-depth interviews with 25 HCWs aged 21 to 63 years from three hospitals from two districts in the central region of Uganda and eight older people from communities in Wakiso district. Selection was purposive based on sex, occupation, education, cadre of HCWs (doctors, nurses, laboratory technologist, hospital support staff, administrator) and vaccination status. We explored participants knowledge, beliefs, personal experiences, barriers, and facilitators to vaccine uptake and suggestions for future COVID-19 vaccine rollout. Interviews were audio-recorded, data was transcribed and translated from the local language, coded, and analysed by themes. Results Twenty-two of the 25 (88%) HCWs and 3 of the 8 (38%) older people had received at least one dose of the COVID-19 vaccine at the time of interview. The structural facilitating factors to vaccine uptake included access to correct information, fear of a risky work environment, and mandatory vaccination requirements especially for frontline HCWs. Old age, chronic health conditions, and the fear of death are contextual facilitating factors, while influence from leaders was the main social facilitating factor. Myths and misconceptions about COVID-19 vaccines and the fear of side effects were common social barriers to vaccine uptake among HCWs and older people. Long distances to vaccination centres, vaccine stock-outs, and long queues at the vaccination centres were specific barriers to vaccine uptake for older people. The prerequisite of signing a consent form was a specific structural barrier for the HCWs. Transport challenges linked to long distances to the vaccination centres, for older people, and having underlying chronic health conditions, for both older people and HCWs, were the reported contextual factors. Conclusion Future roll out of new vaccines should have a comprehensive information dissemination strategy about the vaccines. Improved access to vaccines through community outreaches, reliable vaccine supply and addressing vaccine misinformation, may enhance COVID-19 vaccine uptake in Uganda and other future mass vaccination campaigns.

Pre-pandemic SARS-CoV-2-specific IFN-γ and antibody responses were low in Ugandan samples and significantly reduced in HIV-positive specimens.

Introduction: We investigated whether prior SARS-CoV-2-specific IFN-γ and antibody responses in Ugandan COVID-19 pre-pandemic specimens aligned to this population's low disease severity. Methods: We used nucleoprotein (N), spike (S), NTD, RBD, envelope, membrane, SD1/2-directed IFN-γ ELISpots, and an S- and N-IgG antibody ELISA to screen for SARS-CoV-2-specific cross-reactivity. Results: HCoV-OC43-, HCoV-229E-, and SARS-CoV-2-specific IFN-γ occurred in 23, 15, and 17 of 104 specimens, respectively. Cross-reactive IgG was more common against the nucleoprotein (7/110, 15.5%; p = 0.0016, Fishers' Exact) than the spike (3/110, 2.72%). Specimens lacking anti-HuCoV antibodies had higher rates of pre-epidemic SARS-CoV-2-specific IFN-γ cross-reactivity (p-value = 0.00001, Fishers' exact test), suggesting that exposure to additional factors not examined here might play a role. SARS-CoV-2-specific cross-reactive antibodies were significantly less common in HIV-positive specimens (p=0.017; Fishers' Exact test). Correlations between SARS-CoV-2- and HuCoV-specific IFN-γ responses were consistently weak in both HIV negative and positive specimens. Discussion: These findings support the existence of pre-epidemic SARS-CoV-2-specific cellular and humoral cross-reactivity in this population. The data do not establish that these virus-specific IFN-γ and antibody responses are entirely specific to SARS-CoV-2. Inability of the antibodies to neutralise SARS-CoV-2 implies that prior exposure did not result in immunity. Correlations between SARS-CoV-2 and HuCoV-specific responses were consistently weak, suggesting that additional variables likely contributed to the pre-epidemic cross-reactivity patterns. The data suggests that surveillance efforts based on the nucleoprotein might overestimate the exposure to SARS-CoV-2 compared to inclusion of additional targets, like the spike protein. This study, while limited in scope, suggests that HIV-positive people are less likely than HIV-negative people to produce protective antibodies against SARS-CoV-2.