Inactivated Covid-19 vaccine did not undermine live birth and neonatal outcomes of women with frozen-thawed embryo transfer.

STUDY QUESTION: Does inoculation with inactivated vaccines against coronavirus disease 2019 (Covid-19) before frozen-thawed embryo transfer (FET) affect live birth and neonatal outcomes? SUMMARY ANSWER: Inactivated Covid-19 vaccines did not undermine live birth and neonatal outcomes of women planning for FET. WHAT IS KNOWN ALREADY: Accumulating reports are now available indicating the safe use of mRNA vaccines against Covid-19 in pregnant and lactating women, and a few reports indicate that they are not associated with adverse effects on ovarian stimulation or early pregnancy outcomes following IVF. Evidence about the safety of inactivated Covid-19 vaccines is very limited. STUDY DESIGN, SIZE, DURATION: This is a retrospective cohort analysis from Reproductive Medical Center of a tertiary teaching hospital. Clinical records and vaccination record of 2574 couples with embryos transferred between 1 March 2021 and 30 September 2021 were screened for eligibility of this study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Clinical and vaccination data of infertile couples planning for FET were screened for eligibility of the study. The reproductive and neonatal outcomes of FET women inoculated with inactivated Covid-19 vaccines or not were compared. The primary outcomes were live birth rate per embryo transfer cycle and newborns' birth height and weight. Secondary outcomes included rates of ongoing pregnancy, clinical pregnancy, biochemical pregnancy and spontaneous miscarriage. Multivariate logistical regression and propensity score matching (PSM) analyses were performed to minimize the influence of confounding factors. Subgroup analyses, including single dose versus double dose of the vaccines and the time intervals between the first vaccination and embryo transfer, were also performed. MAIN RESULTS AND THE ROLE OF CHANCE: Vaccinated women have comparable live birth rates (43.6% versus 45.0% before PSM, P = 0.590; and 42.9% versus 43.9% after PSM, P = 0.688), ongoing pregnancy rates (48.2% versus 48.1% before PSM, P = 0.980; and 52.2% versus 52.7% after PSM, P = 0.875) and clinical pregnancy rate (55.0% versus 54.8% before PSM, P = 0.928; and 54.7% versus 54.2% after PSM, P = 0.868) when compared with unvaccinated counterparts. The newborns' birth length (50.0 ± 1.6 versus 49.0 ± 2.9 cm before PSM, P = 0.116; and 49.9 ± 1.7 versus 49.3 ± 2.6 cm after PSM, P = 0.141) and birth weight (3111.2 ± 349.9 versus 3030.3 ± 588.5 g before PSM, P = 0.544; and 3053.8 ± 372.5 versus 3039.2 ± 496.8 g after PSM, P = 0.347) were all similar between the two groups. Neither single dose nor double dose of vaccines, as well as different intervals between vaccination and embryo transfer showed any significant impacts on reproductive and neonatal outcomes. LIMITATIONS, REASONS FOR CAUTION: The main findings might be limited by retrospective design. Besides, inoculations of triple dose of Covid-19 vaccines were not available by the time of data collection, thus the results cannot reflect the safe use of triple dose of inactivated Covid-19 vaccines. Finally, history of Covid-19 infection was based on patients' self-report rather than objective laboratory tests. WIDER IMPLICATIONS OF THE FINDINGS: Eligible individuals of inactivated vaccines against Covid-19 should not postpone vaccination plan because of their embryo transfer schedule, or vice versa. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the Medical Key Discipline of Guangzhou (2021-2023). All authors had nothing to disclose. TRIAL REGISTRATION NUMBER: N/A.

Effect of inactivated COVID-19 vaccination on intrauterine insemination cycle success: A retrospective cohort study.

Background: Vaccine hesitancy was found in couples seeking artificial reproductive technology (ART) services. As the main vaccine used in China, investigations into the influence of inactivated coronavirus disease 2019 (COVID-19) vaccines on human fertility is needed. Methods: This retrospective cohort study included data on COVID-19 vaccination, clinical characteristics, and reproductive outcome of 1,000 intrauterine insemination (IUI) cycles in 653 couples from March 2021 to March 2022 in a single university hospital-based center for reproductive medicine. The IUI cycles were divided into two categories based on sperm source, including 725 cycles in 492 women undergoing artificial insemination with their husband's sperm (AIH) and 275 cycles in 161 women undergoing artificial insemination with donor sperm (AID). Women were then divided into two groups. The vaccine exposed group included women vaccinated prior to insemination and the unexposed group included women who were not vaccinated or vaccinated after insemination. Reproductive outcomes including ongoing pregnancy rate, clinical pregnancy rate, and miscarriage rate were assessed. Results: Inactivated COVID-19 vaccinated women prior to intrauterine insemination in AIH cycles have comparable ongoing pregnancy rate (11.1 vs. 10.3%, P = 0.73), clinical pregnancy rate (12.5 vs. 11.3%, P = 0.60) as compared with unvaccinated counterparts. Similarly, there were no significant differences in ongoing pregnancy rate (20.9 vs. 28.1%, P = 0.17), clinical pregnancy rate (21.7 vs. 28.8%, P = 0.19) between vaccine exposed and unexposed groups in AID cycles. Multivariable logistic regression analyses showed that inactivated COVID-19 vaccination status cannot independently influence the reproductive outcomes of AIH and AID cycles. Subgroup analysis of vaccine exposed cycles showed that doses of vaccination and Interval between the last dose of vaccination and insemination have no influence on the reproductive outcomes of AIH cycles. Conclusions: No negative effects were found on female fertility in IUI cycles following exposure to the inactivated COVID-19 vaccine. These findings indirectly reflect the safety of inactivated COVID-19 vaccine toward reproductive health and help to mitigate vaccine hesitancy among people planning to conceive.

Inactivated COVID-19 vaccination does not affect in vitro fertilization outcomes in women.

STUDY QUESTION: Do inactivated coronavirus disease-2019 (COVID-19) vaccines affect IVF outcomes among the vaccine recipients? SUMMARY ANSWER: The receipt of inactivated COVID-19 vaccines before ovarian stimulation has little effect on the outcomes of IVF, including ovarian stimulation outcomes, embryo development and pregnancy rates. WHAT IS KNOWN ALREADY: Limited studies have reported that COVID-19 vaccines do not affect ovarian function, embryo development or pregnancy outcomes. STUDY DESIGN, SIZE, DURATION: This was a retrospective cohort study performed at the Third Affiliated Hospital of Guangzhou Medical University on 240 women vaccinated with either CoronaVac or Sinopharm COVID-19 before ovarian stimulation in the exposed group and 1343 unvaccinated women before ovarian stimulation in the unexposed group. All participants received fresh embryo transfers between 1 March 2021 and 15 September 2021. The included women were followed up until 12 weeks of gestation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Vaccination information of all subjects was followed up by a nurse, and the IVF data were obtained from the IVF data system. The following aspects were compared between the vaccinated and the unvaccinated groups: parameters of ovarian stimulation, embryo development and pregnancy rates. Regression analyses were performed to control for confounders of embryo development and pregnancy rates. Propensity score matching (PSM) was performed to balance the baseline parameters of the two groups. The primary outcome was the ongoing pregnancy rate. MAIN RESULTS AND THE ROLE OF CHANCE: Liner regression analysis revealed that the number of oocytes retrieved (regression coefficient (B) = -0.299, P = 0.264), embryos suitable for transfer (B = -0.203, P = 0.127) and blastocysts (B = -0.250, P = 0.105) were not associated with the status of vaccination before ovarian stimulation, after adjusting for the confounders. The ongoing pregnancy rate in the women of the vaccinated group was not significantly lower than that in the unvaccinated group (36.3% vs 40.7%, P = 0.199) (adjust odd ratio = 0.91, 95% CI = 0.68-1.22, P = 0.52). After PSM, the rates of ongoing pregnancy (36.0% vs 39.9%, P = 0.272), implantation (35.4% vs 38.3%, P = 0.325), biochemical pregnancy (47.3% vs 51.6%, P = 0.232), clinical pregnancy (44.4% vs 47.4%, P = 0.398) and early miscarriage (15.0% vs 12.1%, P = 0.399) were not significantly different between the vaccinated and the unvaccinated groups. LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study of women with infertility. The results from the present study warrant confirmation by prospective studies with a larger cohort. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study with a large sample size on the effect of inactivated COVID-19 vaccines on ongoing pregnancy rates of women undergoing IVF. The present results showed that vaccination has no detrimental effect on IVF outcomes. Therefore, women are recommended to receive COVID-19 vaccines before undergoing their IVF treatment. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Key Research and Development Program of China (No. 2018YFC1003803 to J.L.), the Guangzhou Science and Technology Plan Project (No. 202102010076 to H.L.) and the Medical Key Discipline of Guangzhou (2021-2023), as well as the Sino-German Center for Research Promotion Rapid Response Funding Call for Bilateral Collaborative Proposals between China and Germany in COVID-19 Related Research (No. C-0032 to Xingfei Pan). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Development of surface‐enhanced Raman scattering‐based immunoassay platforms using hollow Au nanostars for reliable SARS‐CoV‐2 diagnosis

We developed a novel surface‐enhanced Raman scattering (SERS)‐based SARS‐CoV‐2 assay platform using hollow Au nanostars to realize high‐sensitivity diagnosis of SARS‐CoV‐2. The assay was performed using SARS‐CoV‐2 lysate as the target in a wide dynamic range with virus concentrations ranging from 0 to 104 PFU/ml and has a limit of detection (LOD) of 5.1 PFU/ml. This LOD value shows 100 times and 10 times better sensitivity compared to the LODs measured on the same sample using a commercially available rapid kit and enzyme‐linked immunosorbent assay, respectively. Therefore, we believe that this SERS‐based SARS‐CoV‐2 assay platform has high diagnostic accuracy for early or asymptomatic infected patients with low virus concentrations. Furthermore, the probability of a false‐negative diagnosis is likely to be very low. A new magnetic bead‐based SERS assay platform was developed to overcome the sensitivity limit of the commercially available SARS‐CoV‐2 immunodiagnostic kits. A novel hollow gold nanostars (HAuNSs), with a high enhancement factor and good stability, was employed for the detection of nucleocapsid protein from SARS‐CoV‐2. The assay could be performed in a wide dynamic range with virus concentrations ranging from 10−2 to 104 PFU/ml and showed an LOD value of 5.1 PFU/ml using this platform.

SERS-PCR assays of SARS-CoV-2 target genes using Au nanoparticles-internalized Au nanodimple substrates.

The reverse transcription-polymerase chain reaction (RT-PCR) method has been adopted worldwide to diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although this method has good sensitivity and specificity, there is a need to develop a more rapid diagnostic technology, given the virus's rapid spread. However, the RT-PCR method takes a long time to diagnose SARS-CoV-2 because of the required thermocycling steps. Therefore, we developed a surface-enhanced Raman scattering (SERS)-PCR detection method using an AuNP-internalized Au nanodimple substrate (AuNDS) to shorten the diagnosis time by reducing the number of thermocycling steps needed to amplify the DNA. For the representative target markers, namely, the envelope protein (E) and RNA-dependent RNA polymerase (RdRp) genes of SARS-CoV-2, 25 RT-PCR thermocycles are required to reach a detectable threshold value, while 15 cycles are needed for magnetic bead-based SERS-PCR when the initial DNA concentration was 1.00× 105 copies/µL. However, only 8 cycles are needed for the AuNDS-based SERS-PCR. The corresponding detectable target DNA concentrations were 3.36 × 1012, 3.28 × 109, and 2.56 × 107 copies/µL, respectively. Therefore, AuNDS-based SERS-PCR is seen as being a new molecular diagnostic platform that can shorten the time required for the thermocycling steps relative to the conventional RT-PCR.

Development of surface-enhanced Raman scattering-based immunoassay platforms using hollow Au nanostars for reliable SARS-CoV-2 diagnosis.

We developed a novel surface-enhanced Raman scattering (SERS)-based SARS-CoV-2 assay platform using hollow Au nanostars to realize high-sensitivity diagnosis of SARS-CoV-2. The assay was performed using SARS-CoV-2 lysate as the target in a wide dynamic range with virus concentrations ranging from 0 to 104 PFU/ml and has a limit of detection (LOD) of 5.1 PFU/ml. This LOD value shows 100 times and 10 times better sensitivity compared to the LODs measured on the same sample using a commercially available rapid kit and enzyme-linked immunosorbent assay, respectively. Therefore, we believe that this SERS-based SARS-CoV-2 assay platform has high diagnostic accuracy for early or asymptomatic infected patients with low virus concentrations. Furthermore, the probability of a false-negative diagnosis is likely to be very low.

The safety and feasibility of the screening for retinopathy of prematurity assisted by telemedicine network during COVID-19 pandemic in Wuhan, China.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) epidemic, due to the traffic blockade and the shortage of medical resources, more and more premature infants could not receive timely and effective ROP screening, which delayed treatment and even caused children blindness. Therefore, how to carry out ROP screening safely and effectively during the epidemic was very important and urgent. This study aimed to evaluate the safety and feasibility of ROP screening assisted by telemedicine network during COVID-19 outbreak. METHODS: This retrospective study was conducted at Wuhan Children's hospital in Wuhan, China, from January to October, 2020. The measures which were performed to make the ROP screening more safe and effective were summarized and the comparison between ROP screening assisted by telemedicine network in 2020 and usual screening in 2019 were analyzed. RESULTS: A total of 267 outpatient infants completed ROP screening. The median gestational age was 32 weeks (30w to 34w) and the median birth weight was 1780 g (1460 g to 2100 g). Meanwhile, 149 (55.8%) out of 267 infants were males. During January to May in 2020, 86 screening appointments were received, among which 67 (77.9%) were from telemedicine platform online. The completing percentage of total online ROP appointments was higher than that of total face-to-face appointments (58.1% VS 22. 1%, P = 0.018). As for the number of infants screened between 2020 and 2019 from Februaryto October, 54 infants completed ROP screening in 2020, which was higher than that (51participants) in 2019 on September. Furthermore, compared with the usual screening in 2019, ROP screening assisted by telemedicine network in 2020 had smaller gestational age (32w VS 33w, p<0.001) and lower birth weight (1780 g VS 1900 g, p = 0.001). However, of the 267 infants screened, 18(6.7%) had ROP while the percentage of ROP screened in 2019 was the same (44[6.7%]). During follow-up, none of medical staffs was infected and no adverse reaction was reported. CONCLUSIONS: The screening for retinopathy of prematurity assisted by telemedicine network was safe and feasible during the COVID-19 pandemic. Preventive measures before and after screening were very necessary, which could effectively avoid cross infection.