COVID-19 in the Caribbean

Using Regional Sero-Epidemiology SARS-CoV-2 Anti-S Antibodies in the Dominican Republic to Inform Targeted Public Health Response

Incidence of COVID-19 has been associated with sociodemographic factors. We investigated variations in SARS-CoV-2 seroprevalence at sub-national levels in the Dominican Republic and assessed potential factors influencing variation in regional-level seroprevalence. Data were collected in a three-stage cross-sectional national serosurvey from June to October 2021. Seroprevalence of antibodies against the SARS-CoV-2 spike protein (anti-S) was estimated and adjusted for selection probability, age, and sex. Multilevel logistic regression was used to estimate the effect of covariates on seropositivity for anti-S and correlates of 80% protection (PT80) against symptomatic infection for the ancestral and Delta strains. A total of 6683 participants from 134 clusters in all 10 regions were enrolled. Anti-S, PT80 for the ancestral and Delta strains odds ratio varied across regions, Enriquillo presented significant higher odds for all outcomes compared with Yuma. Compared to being unvaccinated, receiving ≥2 doses of COVID-19 vaccine was associated with a significantly higher odds of anti-S positivity (OR 85.94, [10.95-674.33]) and PT80 for the ancestral (OR 4.78, [2.15-10.62]) and Delta strains (OR 3.08, [1.57-9.65]) nationally and also for each region. Our results can help inform regional-level public health response, such as strategies to increase vaccination coverage in areas with low population immunity against currently circulating strains.

Global border restrictions in 2020-2021: Adherence and the effectiveness in long-term COVID-19 epidemic control

BACKGROUND

Restrictions on international travel were widely applied to contain cross-border COVID-19 diffusion, while such applications varied globally, and little was known about their impacts on the long-term epidemic progression.

METHODS

We explored the global diversity in maintaining border policies classified to four levels (screening, quarantine, ban on regions and total border closure) using data of 185 countries and regions between 01 January 2020 to 31 December 2021. By using Ordinary least squares (OLS) regression and quantile regression (QR) models, we examined the relationship between total COVID-19 incidence and the cumulative duration of each policy level in 2020-2021, and the heterogeneity of such association across different transmission severity countries.

RESULTS

Firstly, "ban on regions" was the most durable policy applied in high-income countries, while in low-income countries, less stringent measures of screening and quarantine arrivals were applied the longest. Secondly, the cumulatively longer maintenance of the border quarantine was significantly associated with lower infections (log) in COVID-19 high-prevalent countries (75th QR, coefficient estimates [β] = -0.0038, 95% confidence interval: -0.0066 to -0.0010). By contrast, in medium and high transmission severity countries, those with longer duration of imposing bans on regions showed no suppressing effects but significantly higher COVID-19 incidence (OLS regression, β = 0.0028, 95% CI: 0.0009-0.0047; 75th QR, β = 0.0039, 95% CI: 0.0014-0.0063). No other significant results were found.

CONCLUSION

From the long-term perspective, inbound quarantine was effective in mitigating severe epidemics. However, in countries with medium or high COVID-19 prevalence, our findings of ban on regions highlighted its ineffectiveness in the long-term epidemic progression.

COVID-19 vaccine hesitancy in a developing country: prevalence, explanatory factors and implications for the future

OBJECTIVES

Vaccine hesitancy is a public health challenge highlighted during the COVID-19 pandemic. This study sought to determine the prevalence and explanatory factors leading to COVID-19 vaccine hesitancy in the Jamaican population to inform vaccination strategies.

STUDY DESIGN

This was an exploratory cross-sectional study.

METHODS

An exploratory survey was distributed electronically between September and October 2021 to gather information on COVID-19 vaccination behaviour and beliefs among the Jamaican population. Data were expressed as frequencies and analysed using Chi-squared followed by multivariate logistic regressions. Significant analyses were determined at P < 0.05.

RESULTS

Of the 678 eligible responses, most were females (71.5%, n = 485), between ages 18-45 years (68.2%, n = 462), had tertiary education (83.4%, n = 564) and were employed (73.4%, n = 498), with 10.6% (n = 44) being healthcare workers. COVID-19 vaccine hesitancy was present in 29.8% (n = 202) of the survey population, mainly because of safety and efficacy concerns and a general lack of reliable information about the vaccines. The likelihood of hesitancy increased amongst respondents under 36 years (odds ratio [OR] 6.8, 95% confidence interval [CI] 3.6, 12.9), those who delayed initial acceptance of vaccines (OR 2.7, 95% CI 2.3, 3.1); parents for their children and with long waits at vaccination centres. Likelihood of hesitancy decreased for respondents over 36 years (OR 3.7, 95% CI 1.8, 7.8) and with vaccine support from pastors/religious leaders (OR 1.6, 95% CI 1.1, 2.4).

CONCLUSIONS

Vaccine hesitancy was more prevalent in younger respondents who were never exposed to the effects of vaccine-preventable diseases. Religious leaders had more influence than healthcare workers to increase vaccine uptake.

Impact of Vaccine and Immunity Passports in the Context of COVID-19: A Time Series Analysis in Overseas France

(1) Background: By summer 2021, overseas France turned COVID-19 vaccine and immunity certificates into passports to open travel bubbles. Subsequently, its territories set French records for both COVID-19 and 6-month excess all-cause mortality. (2) Methods: Official time series were collected to compare time correlations between air traffic and COVID-19 transmission and mortality in overseas France, before and after the implementation of immunity passports. (3) Results: Air traffic initially had a reversed relationship with COVID-19, which transitioned into a leader–follower relationship with the introduction of immunity passports. Essentially, air traffic increased 16 days before COVID-19 cases increased (r = 0.61) and 26 days before deaths increased (r = 0.31) in Martinique, 26 days (r = 0.72) and 40 days (r = 0.82) before in Guadeloupe, and 29 days (r = 0.60) and 31 days (r = 0.41) before in Réunion upon introduction of immunity passports. Moreover, air traffic became as correlated as community transmission to COVID-19 mortality in Guadeloupe. (4) Conclusions: Since the introduction of immunity passports, air traffic has been pacesetting COVID-19 within one month for transmission, and within an additional two weeks for mortality in overseas France. Responding to WHO’s call for real-world evidence, this study suggests that COVID-19 passports are not commensurate with health system goals.