Knowledge, attitudes, and practices and long-term immune response after rVSVΔG-ZEBOV-GP Ebola vaccination in healthcare workers in high-risk districts in Uganda.

BACKGROUND: The rVSVΔG-ZEBOV-GP Ebola vaccine (rVSV-ZEBOV) has been used in response to Ebola disease outbreaks caused by Ebola virus (EBOV). Understanding Ebola knowledge, attitudes, and practices (KAP) and the long-term immune response following rVSV-ZEBOV are critical to inform recommendations on future use. METHODS: We administered surveys and collected blood samples from healthcare workers (HCWs) from seven Ugandan healthcare facilities. Questionnaires collected information on demographic characteristics and KAP related to Ebola and vaccination. IgG ELISA, virus neutralization, and interferon gamma ELISpot measured immunological responses against EBOV glycoprotein (GP). RESULTS: Overall, 37 % (210/565) of HCWs reported receiving any Ebola vaccination. Knowledge that rVSV-ZEBOV only protects against EBOV was low among vaccinated (32 %; 62/192) and unvaccinated (7 %; 14/200) HCWs. Most vaccinated (91 %; 192/210) and unvaccinated (92 %; 326/355) HCWs wanted to receive a booster or initial dose of rVSV-ZEBOV, respectively. Median time from rVSV-ZEBOV vaccination to sample collection was 37.7 months (IQR: 30.5, 38.3). IgG antibodies against EBOV GP were detected in 95 % (61/64) of HCWs with vaccination cards and in 84 % (162/194) of HCWs who reported receiving a vaccination. Geometric mean titer among seropositive vaccinees was 0.066 IU/mL (95 % CI: 0.058-0.076). CONCLUSION: As Uganda has experienced outbreaks of Sudan virus and Bundibugyo virus, for which rVSV-ZEBOV does not protect against, our findings underscore the importance of continued education and risk communication to HCWs on Ebola and other viral hemorrhagic fevers. IgG antibodies against EBOV GP were detected in most vaccinated HCWs in Uganda 2─4 years after vaccination; however, the duration and correlates of protection warrant further investigation.

Serologic responses to the MVA-based JYNNEOS mpox vaccine in a cohort of participants from the District of Columbia (D.C.).

We assessed early antibody responses after two doses of JYNNEOS (IMVANEX) mpox vaccine in the District of Columbia (D.C.) in persons at high risk for mpox without characteristic lesions or rash. Participants with PCR mpox negative specimens (oral swab, blood, and/or rectal swab) on the day of receipt of the first vaccine dose and who provided a baseline (day 0) serum sample and at least one serum sample at âˆ¼28, ∼42-56 days, or 180 days post vaccination were included in this analysis. Orthopoxvirus (OPXV)-specific IgG and IgM ELISAs and neutralizing antibody titers were performed, and longitudinal serologic responses were examined. Based on participants' IgG and IgM antibody levels at baseline, they were categorized as naïve or non-naïve. Linear mixed effects regression models were conducted to determine if IgG antibody response over time varied by age, sex, HIV status, and route of administration for both naïve and non-naïve participants. Among both naïve and non-naïve participants IgG seropositivity rates increased until day 42-56, with 89.4 % of naïve and 92.1 % of non-naïve participants having detectable IgG antibodies. The proportion of naive participants with detectable IgG antibodies declined by day 180 (67.7 %) but remained high among non-naïve participants (94.4 %). Neutralizing antibody titers displayed a similar pattern, increasing initially post vaccination but declining by day 180 among naïve participants. There were no significant serologic response differences by age, sex, or HIV status. Serologic response did vary by route of vaccine administration, with those receiving a combination of intradermal and subcutaneous doses displaying significantly higher IgG values than those receiving both doses intradermally. These analyses provide initial insights into the immunogenicity of a two-dose JYNNEOS PEP regimen in individuals at high risk of mpox exposure in the United States.

Epidemiologic and Genomic Evidence for Zoonotic Transmission of SARS-CoV-2 among People and Animals on a Michigan Mink Farm, United States, 2020.

Farmed mink are one of few animals in which infection with SARS-CoV-2 has resulted in sustained transmission among a population and spillback from mink to people. In September 2020, mink on a Michigan farm exhibited increased morbidity and mortality rates due to confirmed SARS-CoV-2 infection. We conducted an epidemiologic investigation to identify the source of initial mink exposure, assess the degree of spread within the facility's overall mink population, and evaluate the risk of further viral spread on the farm and in surrounding wildlife habitats. Three farm employees reported symptoms consistent with COVID-19 the same day that increased mortality rates were observed among the mink herd. One of these individuals, and another asymptomatic employee, tested positive for SARS-CoV-2 by real-time reverse transcription PCR (RT-qPCR) 9 days later. All but one mink sampled on the farm were positive for SARS-CoV-2 based on nucleic acid detection from at least one oral, nasal, or rectal swab tested by RT-qPCR (99%). Sequence analysis showed high degrees of similarity between sequences from mink and the two positive farm employees. Epidemiologic and genomic data, including the presence of F486L and N501T mutations believed to arise through mink adaptation, support the hypothesis that the two employees with SARS-CoV-2 nucleic acid detection contracted COVID-19 from mink. However, the specific source of virus introduction onto the farm was not identified. Three companion animals living with mink farm employees and 31 wild animals of six species sampled in the surrounding area were negative for SARS-CoV-2 by RT-qPCR. Results from this investigation support the necessity of a One Health approach to manage the zoonotic spread of SARS-CoV-2 and underscores the critical need for multifaceted public health approaches to prevent the introduction and spread of respiratory viruses on mink farms.