Malawi vaccination drive: An integrated immunization campaign against typhoid, measles, rubella, and polio; health benefits and potential challenges

Addressing the re-emergence and resurgence of vaccine-preventable diseases in Africa: A health equity perspective

Vaccination is one of the greatest public health achievements of the 20th century, with a tremendous impact in the prevention and control of diseases. However, the recent reemergence of vaccine-preventable diseases calls for a need to evaluate current vaccination practices and disparities in vaccination between high-income countries and low-and-middle-income countries. There are massive deficits in vaccine availability and coverage in resource-constrained settings. Therefore, this perspective seeks to highlight the reemergence of vaccine-preventable diseases in Africa within the lens of health equity and offer recommendations on how the continent should be prepared to deal with the myriad of its health systems challenges. Among the notable factors contributing to the reemergence, stand health inequities affecting vaccine availability and the dynamic vaccine hesitancy. Strengthening health systems and addressing health inequities could prove useful in halting the reemergence of vaccine-preventable diseases.

Quantitative analysis of pertussis, tetanus, and diphtheria antibodies in sera and breast milk from Tdap vaccinated women using a qualified multiplex assay

Pertussis (whooping cough) is a reemergent, highly contagious respiratory infection of public health concern. Infants prior to initiation of their primary vaccination series are the most vulnerable to severe infection, and even death. Vaccination during pregnancy is an efficacious means of reducing infection in infants. This approach relies on boosting maternal immunity and passive transfer of antibodies to the infant via placenta and breast milk. Similarly, maternal vaccination post-partum can enhance maternal-infant immunity. To support the analysis of pertussis immunity in the context of maternal-infant immunization, we developed a high throughput multiplex assay for simultaneous quantification of serum IgG antibodies against pertussis vaccine antigens: pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM2/3), and against tetanus (TT) and diphtheria toxoids (DT), using the Meso Scale Discovery (MSD) platform. The assay was qualified, and specificity, sensitivity, accuracy, precision, linearity, and robustness were demonstrated. The assay was subsequently adapted for quantification of IgG and IgA in breast milk. Applied to a serological survey of pregnant women living in the United States and sub-Saharan Africa, this method revealed differences in magnitude and breadth of antibody profile, consistent with history of vaccination. A longitudinal analysis of Tdap responses in women vaccinated post-partum demonstrated a rapid increase in serum IgG that remained elevated for up to 24 months. Likewise, high levels of vaccine-specific IgA and IgG antibodies were present in breast milk, although they exhibited faster decay. This multiplex MSD assay is a reliable and practical tool for quantification of pertussis, tetanus, and diphtheria antibodies in serum and breast milk in serosurveys or vaccine studies.

IMPORTANCE

Pertussis (whooping cough) has reemerged in recent years. Vaccination during pregnancy is an effective approach to prevent illness during the first months of life. We developed a multiplex assay for quantification of pertussis, tetanus, and diphtheria serum antibodies using the Meso Scale Discovery (MSD) platform; the method was qualified, and specificity, precision, accuracy, linearity, and limits of quantification were defined. It was also adapted for quantification of antibodies in breast milk. We successfully determined serostatus in women from different regions and with different vaccination histories, as well as responses to Tdap in blood and breast milk post-partum. This is the first description of a multiplex assay for the quantification of pertussis, tetanus, and diphtheria antibodies in breast milk.

Perceptions of the COVID-19 Vaccine and Other Adult Vaccinations in Malawi: A Qualitative Assessment

In Malawi, various brands of the COVID-19 vaccine have been offered to the population, but factors including fear of side effects or other risks, uncertainty about benefits, and misinformation created hesitancy toward them. In early 2022, 4% of Malawians were fully vaccinated for COVID-19. Despite multiple promotion efforts, by August 2022, COVID-19 vaccination nationwide was around 15%. To increase COVID-19 vaccination uptake, the research team collected qualitative data in 4 districts with vaccine coverage levels ranging from 1% to 11%. This data collection happened during a cholera outbreak that began in March 2022 and the vaccination efforts to address it. Study participants included male and female members of the general population, social workers, people with comorbidities, health workers, and community leaders (224 participants total, 47% female). In focus group discussions (n=27) and in-depth interviews (n=17), participants compared COVID-19 vaccines with other adult vaccines, such as cholera and tetanus toxoid. A thematic analysis identified themes related to 3 research questions on COVID-19 vaccine concerns, confidence, and delivery affecting uptake. Differences in promotion, delivery (oral versus injection), COVID-19 vaccine card structure, the various brands and boosters, and vaccines being described as required or optional all played a role in distinguishing COVID-19 vaccines from other vaccines and creating suspicion or indifference. Barriers to vaccination in general, such as rumors or knowledge gaps, were amplified by how novel the COVID-19 vaccines were perceived to be and the changing guidance provided over time. By April 2023, more targeted campaign efforts helped increase vaccination rates to 28%. The findings contribute information about how individuals conceptualize and make decisions about adult vaccination, which can, in turn, inform strategies to integrate COVID-19 promotion and delivery with other disease responses in Malawi as well as routine health services in similar settings.

Vaccine hesitancy in Malawi: a threat to already-made health gains

Malawi faces a growing concern about vaccine hesitancy. This threatens to undermine significant strides in the fight against infectious diseases in the country. Vaccine hesitancy in Malawi is driven by multiple factors. This short communication discusses the extent of vaccine hesitancy in Malawi and its main drivers according to SAGE's (Strategic Advisory Group of Expert) 3Cs (confidence, complacency and convenience) model of vaccine hesitancy. As an escalating health concern, it is imperative to address it urgently. It is imperative to address it urgently through comprehensive and sustainable awareness campaigns that should aim to increase acceptance and demand for vaccines.