Use of SMS-linked electronic surveys for COVID-19 case investigation and contact tracing - Marin County, CA, USA.

OBJECTIVES: We sought to quantify the proportion of contacts reported by persons with COVID-19 through a short message service (SMS)-linked survey in comparison to the proportion of contacts reported during a follow-up phone-interview. We also sought to assess improvement in contact tracing timeliness associated with sending SMS-linked surveys. STUDY DESIGN: During December 4-15, 2020, persons identified as COVID-19 cases whose data was entered into Marin County's contact tracing database on even days received a SMS-linked survey and persons whose data was entered on odd days did not; all were called for case investigation and contact tracing. Chi-square test and Fisher's exact test were used to compare demographic data. Chi-square test was used to contrast categorical outcomes, and Wilcoxon's rank-sum test was used for continuous outcomes. RESULTS: Among 350 SMS-linked survey recipients, 85 (24%) responded and 4 (1%) reported contacts using the survey; an additional 303 contacts were reported during phone interviews. Without phone interviews, 99% of reported contacts would have been missed. There was no meaningful difference between study arms in the proportion of contacts notified within 48 h. CONCLUSIONS: This SMS-linked survey had low participation and was not useful for identifying contacts. Phone interviews remained crucial for COVID-19 contact tracing.

COVID-19 Case Investigation and Contact Tracing in the US, 2020.

Importance: Contact tracing is a multistep process to limit SARS-CoV-2 transmission. Gaps in the process result in missed opportunities to prevent COVID-19. Objective: To quantify proportions of cases and their contacts reached by public health authorities and the amount of time needed to reach them and to compare the risk of a positive COVID-19 test result between contacts and the general public during 4-week assessment periods. Design, Setting, and Participants: This cross-sectional study took place at 13 health departments and 1 Indian Health Service Unit in 11 states and 1 tribal nation. Participants included all individuals with laboratory-confirmed COVID-19 and their named contacts. Local COVID-19 surveillance data were used to determine the numbers of persons reported to have laboratory-confirmed COVID-19 who were interviewed and named contacts between June and October 2020. Main Outcomes and Measures: For contacts, the numbers who were identified, notified of their exposure, and agreed to monitoring were calculated. The median time from index case specimen collection to contact notification was calculated, as were numbers of named contacts subsequently notified of their exposure and monitored. The prevalence of a positive SARS-CoV-2 test among named and tested contacts was compared with that jurisdiction's general population during the same 4 weeks. Results: The total number of cases reported was 74 185. Of these, 43 931 (59%) were interviewed, and 24 705 (33%) named any contacts. Among the 74 839 named contacts, 53 314 (71%) were notified of their exposure, and 34 345 (46%) agreed to monitoring. A mean of 0.7 contacts were reached by telephone by public health authorities, and only 0.5 contacts per case were monitored. In general, health departments reporting large case counts during the assessment (≥5000) conducted smaller proportions of case interviews and contact notifications. In 9 locations, the median time from specimen collection to contact notification was 6 days or less. In 6 of 8 locations with population comparison data, positive test prevalence was higher among named contacts than the general population. Conclusions and Relevance: In this cross-sectional study of US local COVID-19 surveillance data, testing named contacts was a high-yield activity for case finding. However, this assessment suggests that contact tracing had suboptimal impact on SARS-CoV-2 transmission, largely because 2 of 3 cases were either not reached for interview or named no contacts when interviewed. These findings are relevant to decisions regarding the allocation of public health resources among the various prevention strategies and for the prioritization of case investigations and contact tracing efforts.

Immunogenicity of an investigational hepatitis B vaccine with a toll-like receptor 9 agonist adjuvant (HBsAg-1018) compared with a licensed hepatitis B vaccine in subpopulations of healthy adults 18-70 years of age.

BACKGROUND: Immunologic response to a complete vaccine regimen of currently licensed alum-adjuvanted hepatitis B vaccines is reduced in several subpopulations, including older adults, men, obese persons, and smokers. Two phase 3 trials in healthy adults demonstrated that 2 doses over 1 month of an investigational hepatitis B vaccine (HBsAg-1018) induced superior seroprotection rates (SPRs) to 3 doses over 6 months of the licensed vaccine Engerix-B (HBsAg-Eng). METHODS: An exploratory analysis of immunogenicity was conducted in subpopulations from pooled data for the 2 phase 3 trials. RESULTS: In each subpopulation, the peak SPR in the HBsAg-1018 group was statistically significantly higher than the peak SPR in the HBsAg-Eng group. Peak HBsAg-1018 SPRs ranged from 91.6% to 99.7%, while peak HBsAg-Eng SPRs ranged from 67.7% to 92.9%. CONCLUSION: In these exploratory analyses, 2 doses of HBsAg-1018 induced statistically significantly higher rates of seroprotection than 3 doses of HBsAg-Eng across all subpopulations.

Immunogenicity and safety of an investigational hepatitis B vaccine with a Toll-like receptor 9 agonist adjuvant (HBsAg-1018) compared with a licensed hepatitis B vaccine in patients with chronic kidney disease and type 2 diabetes mellitus.

BACKGROUND: Many patients with chronic kidney disease (CKD) are hyporesponsive to currently licensed alum-adjuvanted hepatitis B vaccines, including Engerix-B(®) (HBsAg-Eng). Seroprotection rates (SPRs) are further reduced in CKD patients with diabetes mellitus. Three doses of an investigational hepatitis B vaccine (HBsAg-1018) that uses a Toll-like receptor 9 agonist demonstrated superior SPRs to 4 double doses of HBsAg-Eng in a large phase 3 trial of CKD patients. METHODS: A prespecified subgroup analysis of immunogenicity was conducted in CKD participants with type 2 diabetes in the phase 3 trial. RESULTS: In 328 participants, the peak SPR in the HBsAg-1018 group met criteria for noninferiority and superiority to the peak SPR in the HBsAg-Eng group. The peak geometric mean concentration of antibody against hepatitis B surface antigen in the HBsAg-1018 group was statistically significantly higher than in the HBsAg-Eng group. CONCLUSION: HBsAg-1018 induced significantly higher seroprotection than HBsAg-Eng in CKD patients with diabetes.

Intradermal fractional dose inactivated polio vaccine: a review of the literature.

Oral polio vaccine (OPV) will likely be insufficient to completely eradicate polio due to its propensity to mutate into neurovirulent forms and its inability to produce adequate immunity in certain areas of the world. Inactivated polio vaccine (IPV), a killed vaccine which therefore cannot mutate, may be more effective than OPV in certain populations, and will likely be required for global polio eradication. However, the high cost of IPV is prohibitive in many areas of the world. Intradermal administration has the potential to lower the dose, and thus the cost, of IPV. This article reviews the clinical studies to date on intradermal fractional dose polio vaccination. We conclude that intradermal IPV vaccination shows potential as a means to reduce the cost and increase the ease of administration of IPV, but that additional research is needed to determine the optimal fractional dose, timing, and role of adjuvants in intradermal IPV vaccination as well as the clinical significance of different antibody titers above the threshold for seroconversion.