The effect of herd immunity thresholds on willingness to vaccinate

Achieving herd immunity in South America

South America, once an epicenter of COVID-19, has stayed on the road of continued management of the pandemic. The region initially struggled to cope with the pandemic as it experienced spiraling numbers of infections and overwhelmed public health systems. South America has risen in its pandemic response to be the region with the highest global vaccination rate. The region posed a strong vaccination drive, with over 76% of its population fully vaccinated with the initial protocol. South America leveraged its deeply rooted vaccination culture and public health confidence among its population. Herd immunity is an integral concept in population infectious disease management. Attaining herd immunity is presently not feasible with available vaccines, but the high vaccination rate in the region depicts the acceptance of vaccination as a strategy for population protection. The availability of effective transmission-blocking vaccines, the continuous implementation of strategies that will enable the undisrupted supply of the vaccines, equity in access to the vaccines, improved vaccine acceptance, and trust in the vaccination and public health systems will help shepherd the region towards herd immunity. Local vaccine production backed with investment in infrastructure and international collaboration for research and knowledge development will also drive population safety.

Association between RNAm-Based COVID-19 Vaccines and Permanency of Menstrual Cycle Alterations in Spanish Women: A Cross-Sectional Study

Introduction: The purpose of this study was to delve more deeply into the medium and long-term relation between mRNA-based vaccines and changes in menstrual pain, cycle length, and amount of bleeding in Spanish women. Material and Methods: A total of 746 women (63% between 18−30 and 37% between 31−45 years old) participated in the study. A numerical rating scale was used for recording pain intensity, a pictorial chart for menstrual bleeding, and data from menstrual cycle duration, type of vaccine, number of doses and time from vaccination. Results: Sixty-five per cent of the women perceived changes in their menstrual cycle after receiving the vaccines, irrespective of type of vaccine or number of doses; all p values were >0.05. Most of them (n = 316 out of 484) reported more than one alteration in their menstrual cycle. Almost half of the participants had been vaccinated over 5 months (45%), 3−4 months (15%) 2−3 months (26%), and one month or less (13%) before. The percentage of women that reported alterations remained strongly constant across time, p > 0.05, ranging from 64 to 65%. Conclusions: Reported alterations in Spanish women after COVID vaccination remained more than 5 months after the last dose.