Dengue fever (DF) is a significant public health problem in the African continent. The primary prevention strategy against the disease is vaccination and entomological control of vectors; however, implementing such a strategy in several countries in the continent is far below what is necessary to control the disease. The Coronavirus disease (COVID‐19) pandemic further aggravated this situation and negatively impacted these measures, mainly the coverage of vaccination campaigns, due to restrictive measures to control the disease. Therefore, the most significant risk is that the incidence of DF in the continent will increase even more in the coming years, as a reflection of the negative impact of the pandemic on the control of the disease. To prevent another public health crisis, immediate and multidisciplinary approaches are required to address the epidemiological control of DF in African countries.

Chikungunya virus (CHIKV); Chikungunya (CHIK); enzyme-linked immunosorbent assay (ELISA); immunoglobulin G or M (IgG/IgM); odds ratio (OR); non-structural proteins (nsP); hemagglutination inhibiting (HI); complement fixing (CF); neutralization test (NT); immunofluorescence assay (IFA); plaque reduction neutralization test (PRNT); confidence interval (CI); analysis of variance (ANOVA); body temperature (BT); Building Nigeria's Response to Climate Change (BNRCC).

The saliva of hematophagous arthropods contains a group of active proteins to counteract host responses against injury and to facilitate the success of a bloodmeal. These salivary proteins have significant impacts on modulating pathogen transmission, immunogenicity expression, the establishment of infection, and even disease severity. Recent studies have shown that several salivary proteins are immunogenic and antibodies against them may block infection, thereby suggesting potential vaccine candidates. Here, we discuss the most relevant salivary proteins currently studied for their therapeutic potential as vaccine candidates or to control the transmission of human vector-borne pathogens and immune responses against different arthropod salivary proteins.

Dengue fever, caused by the dengue virus (DENV), is currently a threat to about half of the world's population. DENV is mainly transmitted to the vertebrate host through the bite of a female Aedes mosquito while taking a blood meal. During this process, salivary proteins are introduced into the host skin and blood to facilitate blood acquisition. These salivary proteins modulate both local (skin) and systemic immune responses. Several salivary proteins have been identified as immunogenic inducing the production of antibodies with some of those proteins also displaying immunomodulatory properties enhancing arboviral infections. IgG antibody responses against salivary gland extracts of a diverse number of mosquitoes, as well as antibody responses against the Ae. aegypti peptide, Nterm-34 kDa, have been suggested as biomarkers of human exposure to mosquito bites while antibodies against AgBR1 and NeSt1 proteins have been investigated for their potential protective effect against Zika virus (ZIKV) and West Nile virus infections. Thus, we were interested in evaluating whether IgG antibodies against AgBR1, NeSt1, Nterm-34 kDa peptide, and SGE were associated with DENV infections and clinical characteristics. For this, we tested samples from volunteers living in a dengue fever endemic area in Colombia in 2019 for the presence of IgG antibodies against those salivary proteins and peptides using an ELISA test. Results from this pilot study suggest an involvement of antibody responses against salivary proteins in dengue disease progression.

Coronavirus disease 2019 (COVID-19) and measles are major threats to the health and wellbeing of Africans. Measles is an endemic disease in Africa with a high mortality rate especially in children despite available vaccines. This letter aims to discuss the impact of the COVID-19 pandemic on prevention and management of measles in Africa. The emergence of COVID-19 has exacerbated the morbidities of measles due to multi-factors like the disruption of mass measles routine vaccination, a monopolistic focus on COVID-19 eradication, malnutrition, and poor surveillance. Currently, the COVID-19 pandemic and looming measles epidemic pose a double burden on the African health sector. We recommend urgent interventions from government and other stakeholders including community leaders to strengthen measles research and vaccination programs in Africa amidst the pandemic.