Evaluating Johnson and Johnson COVID-19 Vaccination Outcomes in a Low-Income Hispanic Population

The COVID-19 pandemic, while receding in many areas due to widespread vaccination, continues to pose significant challenges, particularly in vulnerable populations. The study emphasizes that although over 12.97 billion doses of various COVID-19 vaccines have been administered globally, resulting in a decrease in the pandemic's severity and a shift to endemic status in many high-vaccination countries, vaccine efficacy wanes over time, necessitating booster shots. The underlying mechanism of action isn't fully understood, although an adaptive immune response involving neutralizing antibodies and memory cells is assumed. However, antibody levels decline significantly within six months. The study focuses on the J&J vaccine, a single-shot option, which has seen limited use despite demonstrating comparable effectiveness to other authorized vaccines in some studies. The researchers highlight the underrepresentation of Hispanic populations in COVID-19 vaccine effectiveness studies despite their disproportionate impact of the pandemic. This study aims to address this gap by evaluating the J&J vaccine's outcomes in a low-income Hispanic community served by Alivio Medical Center in Indianapolis, Indiana. The study also aims to determine whether inexpensive and readily available antibody tests can be effectively used to monitor vaccine effectiveness within this community.

Existing literature shows inconsistent results regarding the efficacy and adverse effects of the J&J COVID-19 vaccine across different ethnic groups. Some studies indicate that Hispanic patients experience fewer adverse events than other racial groups, while others report worse standardized mortality rates in Hispanic patients who received the J&J vaccine. This discrepancy highlights the need for more research to elucidate the nuances of vaccine effectiveness and safety among various ethnicities. The literature also highlights the disproportionate impact of COVID-19 on Hispanic populations due to factors such as occupational exposure and limited access to work-from-home options. The limited number of studies exploring these disparities further motivates this investigation.

This prospective, longitudinal observational study enrolled COVID-19 antibody-negative, low-income Hispanic patients from Alivio Medical Center who received the J&J COVID-19 vaccine. Participants were tested for anti-spike (S) IgG antibodies at baseline and at 3 and 6 months post-vaccination using the Clungene SARS-CoV-2 IgG/IgM Rapid Test. The study collected demographic, socioeconomic, and clinical data from electronic medical records and patient interviews. The Clungene test, a rapid point-of-care lateral flow immunoassay (LFA) capable of detecting both IgM and IgG antibodies targeting spike and nucleocapsid proteins, was selected for its ease of use, affordability, and existing validations. Correlation analyses were performed to assess relationships between antibody responses and various patient characteristics. The study was conducted under Western IRB approval, with informed consent obtained from all participants. The study staff was fluent in Spanish to facilitate communication with participants.

The study included 74 initially requested participants; 53 qualified for participation, and 39 returned for at least one follow-up appointment. Only 14% of the 39 participants showed a detectable antibody response after a single J&J vaccine dose. Of the 39 participants, 16 (41%) tested negative for antibodies at one or more follow-up appointments; 5 (12%) reported negative in both appointments, 10 (26%) reported for one appointment, and 1 (3%) was negative then became positive. The remaining 23 (59%) participants tested positive during one or both appointments; 15 (38%) reported positive in both appointments and 8 (21%) reported for one appointment. Correlation analysis revealed a weak to moderate negative correlation between antibody response and time since vaccination, indicating a decline in antibody levels over time. Further analyses of subgroups based on the time of the follow-up visits revealed various correlations between antibody presence and various patient factors. For instance, in the subgroup of patients who visited less than 30 days after vaccination (N = 15 visits), there was a positive correlation between positive antibody results and female gender, whereas a negative correlation was observed between a positive antibody response and age, hypertension, hyperlipidemia and fatigue. For the group with visits 30-60 days after vaccination, there was a positive correlation between a positive result and being male, diabetes, hypertension, weight, and nausea.

The study's findings suggest limited efficacy of the J&J vaccine in this specific low-income Hispanic population, with a considerable proportion of participants failing to mount a detectable antibody response. The observed correlations between various patient factors (age, gender, comorbidities) and antibody response highlight the need to consider these factors when assessing vaccination outcomes in diverse populations. The study's findings underscore the vulnerability of low-income Hispanic communities to COVID-19 and highlight potential disparities in vaccine effectiveness. While the small sample size limits generalizability, the results provide valuable insights and suggest the need for further research to determine if similar results are seen in broader populations. The inexpensive, point-of-care antibody test used in the study appears to be useful in assessing vaccine effectiveness and can potentially be utilized as an adjunct to assist community-based physicians in assessing the health status of their patients within these vulnerable communities.

This study demonstrates the vulnerability of a low-income Hispanic population to COVID-19 and highlights the limited efficacy of the J&J vaccine within this specific group. Socioeconomic factors appear to play a role in vaccine effectiveness. The use of low-cost point-of-care antibody tests could improve monitoring of vaccine efficacy in these communities. Further research is needed to understand these disparities better and improve healthcare strategies for vulnerable populations.

The study's limitations include its small and heterogeneous convenience sample size, limiting generalizability. The absence of assays for neutralizing antibodies, B-cell memory, and T-cell responses limits the comprehensive assessment of immune response. The limited sample size also affects the reliability of correlation analysis, particularly in sub-group analyses where small numbers of patients influence the results. Scheduling challenges due to work and clinic availability impacted participant retention and may have reduced the sample size further.