Effect of COVID-19 on sperm parameters: pathologic alterations and underlying mechanisms.

The rapid outbreak of the coronavirus disease 2019 (COVID-19) pandemic has brought challenges to different medical fields, especially reproductive health. To date, most studies on the effects of COVID-19 on male reproduction have some limitations. In addition, there is little research on the mechanisms underlying by which severe acute respiratory syndrome coronavirus 2 infection affects semen quality. Here, we revealed the possible impact of COVID-19 on sperm parameters and the potential mechanisms. At present, it is still controversial whether COVID-19-induced fever adversely affects sperm parameters. Severe acute respiratory syndrome coronavirus 2 can induce up-regulation of pro-inflammatory cytokine, which leads to the destruction of blood-testis barrier and impairment of spermatogenesis. Moreover, severe viral infection of the respiratory system could induce systemic oxidative stress. Sperm are highly vulnerable to it due to their limited levels of antioxidant defense, unsophisticated DNA damage detection and repair mechanisms. Our review prompt medical staff and patients to consciously check the reproductive function of COVID-19 male patients. Moreover, opening our prospective beyond the direct infection could be the key to better understand the COVID-19 short and long-term effects and provide a new idea for future treatment of patients with reproductive function injury.

Vaccination options for pregnant women during the Omicron period.

Omicron exhibits reduced pathogenicity in general population than the previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. However, the severity of disease and pregnancy outcomes of Omicron infection among pregnant women have not yet been definitively established. Meanwhile, substantial proportions of this population have doubts about the necessity of vaccination given the reports of declining efficacy of coronavirus disease 2019 (COVID-19) vaccines. Herein, we comprehensively discuss the clinical outcomes of infected pregnant women during the Omicron period and summarize the available data on the safety and efficacy profile of COVID-19 vaccination. The results found that the incidence of moderate and severe disease, maternal mortality, pregnancy loss, preterm delivery, stillbirth, preeclampsia/eclampsia, and gestational hypertension during the Omicron period are similar to those during the Pre-Delta period. In view of the effects of mass vaccination and previous natural infection on disease severity, the virulence of Omicron in pregnant women may be comparable to or even higher than that of the Pre-Delta variant. Moreover, the currently approved COVID-19 vaccines are safe and effective for pregnant women. Particularly, those who received a second or third dose had significantly less severe disease with little progression to critical illness or death compared with those who were unvaccinated or received only one dose. Therefore, in the case of the rapid spread of Omicron, pregnant women should still strictly follow preventive measures to avoid infection and receive the COVID-19 vaccine in a timely manner.

The importance of booster vaccination in the context of Omicron wave.

Omicron (B.1.1.529) was first detected in a sample collected in Botswana on November 11, 2021, and has rapidly replaced Delta as the dominant global variant given the robust transmissibility. Moreover, it displays a lower virulence than other variants. However, the pathogenicity of Omicron appears to be underestimated in view of the increasing levels of herd immunity through natural infection or vaccination. Additionally, the volume of hospitalizations and deaths increase in proportion to the number of cases due to the high transmissibility of Omicron. Therefore, vaccination remains an important public health priority. Notably, a series of important mutations in the Omicron spike protein, especially in the receptor-binding domain and N-terminal domain, appears to be associated with immune escape capacity, reducing the willingness of people to receive vaccines. Herein, we provide an in-depth discussion to assess the effectiveness of the second and third vaccination against Omicron variant. On the one hand, the two-dose vaccination program adopted by many countries is insufficient to prevent Omicron infection given the mutations correlated with immune escape and the decline in vaccine efficacy over time. On the other hand, booster dose significantly increases the protective efficacy against Omicron infection. Most importantly, heterologous third dose vaccination induces a more robust immune response than homologous booster dose. Therefore, under the special background of this pandemic, there is an urgent need to accelerate the third dose of vaccination, especially providing better booster vaccination strategies, to combat emerging Omicron variant.

Latest Effective Measures to Combat COVID-19: A Review.

More and more people realize that implementation of preventive measures is the only option left to counteract the coronavirus disease 2019 (COVID-19) before specific antiviral drugs are developed. Hence, a number of behavioral, clinical and state interventions have been conducted by dozens of countries to stop or slow down the spread of the virus in the early stages of the epidemic. At present, with the evolution of COVID-19 pandemic getting worse, synthesizing and implementing all measures available are of paramount importance. However, some measures are still being controversial. We aimed to assist policymakers in decision making for better pandemic preparedness. We reviewed the literature that reported accumulated scientific experience to date and summarized the epidemic prevention and control measures in three aspects: control the source of infection, cut off the routes of transmission and protect the susceptible population. First of all, some new approaches were introduced to control the source of infection, such as implementing contact-tracing apps, nucleic acid mixed detection, repeated testing and the establishment of some specialized laboratories. Second, we need to take various measures to cut off all possible routes of transmission, especially persistently pay close attention to checking cold chain foods. Third, due to no valid vaccine has yet been developed, some measures that can cut development time of more conventional vaccines should be implemented or considered. By synthesizing the scientific experience in fighting the COVID-19 epidemic, we suggested the latest effective measures should be carried out concurrently from three aspects, so as to avoid making grim situation even worse.