In depth analysis of patients with severe SARS-CoV-2 in sub-Saharan Africa demonstrates distinct clinical and immunological profiles.

Although the COVID-19 pandemic has left no country untouched there has been limited research to understand clinical and immunological responses in African populations. Here we comprehensively characterise patients hospitalised with suspected or confirmed COVID-19, and healthy community controls. PCR-confirmed COVID-19 participants were more likely to receive dexamethasone and a beta-lactam antibiotic, and survive to hospital discharge than PCR-/IgG+ and PCR-/IgG-participants. PCR-/IgG+ participants exhibited a nasal and systemic cytokine signature analogous to PCR-confirmed COVID-19 participants, but increased propensity for Staphylococcus aureus and Streptococcus pneumoniae colonisation. We did not find evidence that HIV co-infection in COVID-19 participants was associated with mortality or altered cytokine responses. The nasal immune signature in PCR-/IgG+ and PCR-confirmed COVID-19 participants was distinct and predominated by chemokines and neutrophils. In addition, PCR-/IgG+ individuals with high COVID-19 clinical suspicion had inflammatory profiles analogous to PCR-confirmed disease and potentially represent a target population for COVID-19 treatment strategies.

Antibodies against Haemophilus influenzae type b in The Gambia: investigating the extent of protection across age groups.

Following a landmark clinical trial, the vaccine against Haemophilus influenzae type b (Hib) was introduced in The Gambia in 1997. Whilst the immunogenicity of this vaccine is well established subsequent to the doses administered under the EPI schedule, little data exists assessing longevity of protection, using serology. Such data are needed however to predict the susceptibility to Hib at the population level. To determine antibody persistence in 5-6 year old fully vaccinated Gambian children compared with older children, adolescents and young adults, 427 serum samples from healthy 5-37 year old participants were tested for Hib antibodies using VaccZyme Human Anti-Hib ELISA kits. 86% of the children who had received 3 doses of Hib vaccine in infancy had Hib antibody concentrations ≥0.15 mg/l at the age of 5-6 years. This proportion was 76% for adolescents who had also largely been vaccinated and 90% for adults who had never received Hib vaccine. Although most participants had anti-Hib antibody above concentrations putatively defined as protective, significantly fewer had concentrations thought to confer long-term protection. This suggests a population with insufficient or waning antibody that may be susceptible to breakthrough disease and transmission.