Aug 4 2022;doi:10.1093/cid/ciac637, Levy M, Recher M, Hubert H, et al. You can review and change the way we collect information below. doi:10.1016/j.cmi.2021.07.030, Abu-Raddad LJ, Chemaitelly H, Bertollini R, National Study Group for C-E. Severity of SARS-CoV-2 Reinfections as Compared with Primary Infections. Sep 2021;8(9):ofab428. Science brief: Omicron (B.1.1.529) variant. MMWR Morb Mortal Wkly Rep. Aug 5 2022;71(31):993-999. doi:10.15585/mmwr.mm7131a3, Zavala M, Ireland G, Amin-Chowdhury Z, Ramsay ME, Ladhani SN. URL addresses listed in MMWR were current as of May 19 2022;386(20):1899-1909. doi:10.1056/NEJMoa2202826, Zambrano LD, Ellington S, Strid P, et al. Clin Infect Dis. Finally, increasing patient numbers might have influenced the quality of contact tracing by the PHC. SARS-CoV-2 Spike Antibody, Dominican Republic, https://www.who.int/en/activities/tracking-SARS-CoV-2-variants, https://www.niid.go.jp/niid/en/2019-ncov-e/11411-covid19-ab94th-en.html, https://www.niid.go.jp/niid/en/2019-ncov-e/2484-idsc/9472-2019-ncov-02-en.html, https://www.pref.ibaraki.jp/1saigai/2019-ncov/shiryouteikyou.html, https://www.pref.ibaraki.jp/hokenfukushi/eiken/kikaku/covid-19_ibarakieiken_kensa.html, https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000121431_00333.html, https://www.mhlw.go.jp/content/000968056.pdf, SARS-CoV-2 Incubation Period during the Omicron BA.5Dominant Period in Japan, U.S. Department of Health & Human Services, Ogata T, Tanaka H. SARS-CoV-2 Incubation Period during the Omicron BA.5Dominant Period in Japan. Mar 2021;82(3):329-338. doi:10.1016/j.jinf.2021.01.022, Di Fusco M, Lin J, Vaghela S, et al. MMWR Morb Mortal Wkly Rep. Apr 30 2021;70(17):644-650. doi:10.15585/mmwr.mm7017e3, Chevinsky JR, Tao G, Lavery AM, et al. N Engl J Med. Of the 1,216 samples collected during January 3February 6 in Ibaraki, a total of 1,158 (95%) were negative for the SARS-CoV-2 spike protein mutation L452R (8). The best way to protect yourself and those around you is to get vaccinated, Oller said. N Engl J Med. Specific symptom information was available from 37 symptomatic persons. doi:10.1093/cid/ciac471, Godfred-Cato S, Abrams JY, Balachandran N, et al. References to non-CDC sites on the Internet are Paediatric hospitalisations due to COVID-19 during the first SARS-CoV-2 omicron (B.1.1.529) variant wave in South Africa: a multicentre observational study. University of Texas at Austin. May 19 2021;373:n1098. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page. It appears that a person is likely to be most infectious one to two days before symptoms appear, which continues for a few days after the symptoms begin, Weiss said. Update on Omicron. MMWR Morb Mortal Wkly Rep. Nov 26 2021;70(47):1640-1645. doi:10.15585/mmwr.mm7047e1, Hcini N, Maamri F, Picone O, et al. according to reports from the CDC. Incubation periods can. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.. Heres what that means for infected individuals. The incubation period is the period from when a person becomes infected to when they start showing symptoms. 45 C.F.R. Omicrons incubation period is about two to four days, which is generally shorter than the previous variants. (CDC) shows the seven-day moving average of covid-19 cases was 26,106 as of April 1, ever so slightly lower than 26,309 from a week earlier. On November 28, CDC expanded a voluntary airport-based genomic surveillance program in Atlanta, New York City, Newark, and San Francisco to prioritize recruitment of travelers from southern Africa for testing. 2021;156(2):185-197. doi:10.1093/ajcp/aqab052, Levi M, Thachil J, Iba T, Levy JH. The estimated mean incubation period for patients during the Omicron BA.5dominant period in this region was 2.6 days. Mutations in Omicron might increase transmissibility, confer resistance to therapeutics, or partially escape infection- or vaccine-induced immunity. 2022:o110. ** Based on CDC analysis of the sequences currently available, and accounting for clustering, CDC estimates a 95% chance of detecting the Omicron variant if it accounted for 0.03% of circulating SARS-CoV-2 lineages during the week ending November 13 and for 0.05% of circulating lineages during the week ending November 20 (4). MMWR and Morbidity and Mortality Weekly Report are service marks of the U.S. Department of Health and Human Services. (15) Images of cutaneous findings in COVID-19 are available from the American Academy of Dermatology. BMC Infect Dis. How long are. 2020/06/01/ 2020;7(6):e438-e440. Shorter incubation period among unvaccinated Delta variant coronavirus disease 2019 patients in Japan. Clin Infect Dis. 2021:n385. The Lancet Child & Adolescent Health. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance. BMJ. Scientists in South Africa and elsewhere have established systems that allow study of the laboratory, clinical, and epidemiologic characteristics; CDC is collaborating with health officials around the world to learn more about the characteristics of patients with Omicron variant infections. COVID-19 vaccine effectiveness among immunocompromised populations: a targeted literature review of real-world studies. The first patient infected with SARS-CoV-2 Omicron BA.5 was reported on July 4, 2022, to the Itako PHC in Ibaraki Prefecture, Japan. Disparities in First Dose COVID-19 Vaccination Coverage among Children 5-11 Years of Age, United States. Association between COVID-19 diagnosis and presenting chief complaint from New York City triage data. 2022;5(2):e2143151. We thank the staff of the Itako Public Health Center, Ibaraki Prefectural Institute of Public Health, and government of Ibaraki Prefecture for their contributions to our study. doi:10.5888/pcd18.210123, Ko JY, Danielson ML, Town M, et al. Persons aged 18 years who completed a primary mRNA COVID-19 vaccination series 6 months previously or who received an initial Janssen (Johnson & Johnson) vaccine dose 2 months previously should receive a booster dose; persons aged 1617 years are eligible to receive a Pfizer-BioNTech COVID-19 booster dose >6 months after completion of the primary series. Risk of long COVID associated with delta versus omicron variants of SARS-CoV-2. MMWR Morb Mortal Wkly Rep. Feb 4 2022;71(5):177-181. doi:10.15585/mmwr.mm7105e1, Olson SM, Newhams MM, Halasa NB, et al. CDC COVID-19 Response Team (View author affiliations). Procedures used for contact tracing and data collection for patient pairs with COVID-19 were similar to those described previously (6,7). The incubation period in this study for patients during the BA.5dominant period was markedly shorter than that for patients during the Delta-dominant period; this result is supported by those from previous studies (10,11). BMC Pregnancy Childbirth. No hospitalizations or deaths were reported. Effectiveness of a Third Dose of Pfizer-BioNTech and Moderna Vaccines in Preventing COVID-19 Hospitalization Among Immunocompetent and Immunocompromised Adults - United States, August-December 2021. Centers for Disease Control and Prevention. Dec 2021;27(12):1860 e7-1860 e10. Bjog. The clinical severity of infection with the Omicron variant will become better understood as additional cases are identified and investigated. Characteristics and Disease Severity of US Children and Adolescents Diagnosed With COVID-19. MMWR Morb Mortal Wkly Rep. Sep 10 2021;70(36):1255-1260. doi:10.15585/mmwr.mm7036e2, Siegel DA, Reses HE, Cool AJ, et al. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website. doi:10.1001/jamanetworkopen.2021.43151, Kompaniyets L, Agathis NT, Nelson JM, et al. (9), Fever, cough, shortness of breath, fatigue, headache, and myalgia are among the most commonly reported symptoms in people with COVID-19. Epidemiology of Infections with SARS-CoV-2 Omicron BA.2 Variant, Hong Kong, January-March 2022. Overall, 21 (91%) of 23 interviewed attendees participated in the convention all 3 days. 2021;237(1):1-12. doi:10.1159/000512932, Thompson HA, Mousa A, Dighe A, et al. BNT162b2 mRNA Vaccination Against COVID-19 is Associated with Decreased Likelihood of Multisystem Inflammatory Syndrome in U.S. Children Ages 5-18 Years. The number of confirmed COVID-19 cases from July 4 through August 19, 2022, was 12,577 in the PHCs jurisdiction, which has a population of 265,000 persons (5). (16) Both people who have been vaccinated and those who have not been vaccinated can transmit virus. As a result of the more contagious BA.4 and BA.5 omicron subvariants, COVID-19's incubation period has changed in recent months, Chicago's top doctor previously revealed. Cough. Some older adults can experience COVID-19 infection accompanied by delirium, falls, reduced mobility or generalized weakness, and glycemic changes. These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. Notes from the Field: SARS-CoV-2 Omicron Variant Infection in 10 Persons Within 90 Days of Previous SARS-CoV-2 Delta Variant Infection - Four States, October 2021-January 2022. doi:10.1136/bmj-2021-068632, Embi PJ, Levy ME, Naleway AL, et al. doi:http://dx.doi.org/10.15585/mmwr.mm7113e1, Pingali C, Meghani M, Razzaghi H, et al. Incubation period is defined as the interval from earliest possible exposure of household contacts to the index patient until symptom onset. Omicron is swifter still, with an incubation period of roughly three days, according to a recent C.D.C. The Centers for Disease Control and Prevention recently shortened its isolation guideline s, citing evidence that COVID is most contagious 1 to 2 days before someone starts feeling symptoms and 2 to 3 days after. The American Journal of Emergency Medicine. doi:10.1001/jamanetworkopen.2021.11182, Feldstein LR, Tenforde MW, Friedman KG, et al. Jun 1 2021;4(6):e2111182. Accessed December 3, 2021. Shorter incubation period among COVID-19 cases with the BA.1 Omicron variant. EClinicalMedicine. Details are available for 43 cases of COVID-19 attributed to the Omicron variant; 25 (58%) were in persons aged 1839 years (Table). The CDC released early information on 43 cases attributed to omicron in the U.S. from Dec. 1 to 8, saying 34 of those individuals were fully vaccinated, including 14 who had gotten a booster dose . Mar 2022;10(3):e326-e328. SARS-CoV-2 Incubation Period during the Omicron BA.5-Dominant Period in Japan On This Page The Study. A study of the Oslo Christmas party outbreak found the incubation period could be about three days, compared with 4.3 days for delta and five days for other variants. Tables Table 1. Coronavirus (COVID-19) Infection Survey Technical Article: Impact of vaccination on testing positive in the UK. Saving Lives, Protecting People, Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the, The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. New loss of taste or smell . Department of Health and Human Services. Post-COVID-19 Symptoms and Conditions Among Children and Adolescents - United States, March 1, 2020-January 31, 2022. All information these cookies collect is aggregated and therefore anonymous. doi:10.1016/S2213-2600(22)00011-X, Jayk Bernal A, Gomes da Silva MM, Musungaie DB, et al. Centers for Disease Control and Prevention. Jul 2021;6:100109. doi:10.1016/j.lanepe.2021.100109, Kim L, Garg S, O'Halloran A, et al. MMWR Morb Mortal Wkly Rep. Dec 31 2021;70(5152):1782-1784. doi:10.15585/mmwr.mm705152e3, Song JS, Lee J, Kim M, et al. What we know about quarantine and isolation. Read our. MMWR Morb Mortal Wkly Rep. Jun 19 2020;69(24):759-765. doi:10.15585/mmwr.mm6924e2, Roxby AC, Greninger AL, Hatfield KM, et al. Effectiveness of Pfizer-BioNTech and Moderna Vaccines Against COVID-19 Among Hospitalized Adults Aged >/=65 Years - United States, January-March 2021. COVID Incubation Period Has Changed and Chicago's Top Doc Says That's 'Good News' During her Facebook Live last week, Chicago Department of Public Health Commissioner Dr. Allison Arwady. Many of the first reported cases of Omicron variant infection appear to be mild (7), although as with all variants, a lag exists between infection and more severe outcomes, and symptoms would be expected to be milder in vaccinated persons and those with previous SARS-CoV-2 infection than in unvaccinated persons. A new variant of SARS-CoV-2 (the virus that causes COVID-19), B.1.1.529 (Omicron) (1), was first reported to the World Health Organization (WHO) by South Africa on November 24, 2021. The method is based on rapid screening for S-gene target failures (SGTFs) by polymerase chain reaction (PCR)based diagnostic assays to flag potential cases of Omicron variant infection for confirmation by genomic sequencing (5). Users are referred to the electronic PDF version (https://www.cdc.gov/mmwr) Symptoms can change over the course of illness and can progress in severity. Multisystem inflammatory syndrome in adults (MIS-A): case finding through systematic review of electronic medical records. MMWR Morb Mortal Wkly Rep. Jul 3 2020;69(26):841-846. doi:10.15585/mmwr.mm6926e3, Clifford CT, Pour TR, Freeman R, et al. The Omicron variant has an incubation period of about three days, which is shorter than the incubation period for other variants of the virus that cause COVID-19. The incubation period might be influenced by various factors, such as viral load, environmental setting, patient immune response, severity of disease, and selection biases. 241(d); 5 U.S.C. They help us to know which pages are the most and least popular and see how visitors move around the site. With the original COVID-19 variant, symptoms showed up on average around five to six days after contact with an infected person, [while] the Delta variants incubation period was around four days, Beth Oller, MD, a family physician at Solomon Valley Family Medicine, told Verywell. Sep 18 2020;doi:10.1093/cid/ciaa1419, Wortham JM, Lee JT, Althomsons S, et al. October 2021; The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website. According to the CDC, the incubation period for COVID is between two and 14 days, though the newest guidance from the agency suggests a quarantine of five days for those who are not boosted, but eligible or unvaccinated. Open Forum Infect Dis. Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. (14) Some skin manifestations may be associated with increased disease severity. The CDC recommends that everyone ages 5 years and older get fully vaccinated to. CDC twenty four seven. Aug 1 2021;175(8):837-845. doi:10.1001/jamapediatrics.2021.0630, Miller AD, Zambrano LD, Yousaf AR, et al. What are the implications for public health practice? We enrolled COVID-19 infector/infectee pairs who lived within the Itako PHC jurisdiction and had a single definite close contact date with patients who had COVID-19 without other potential transmission settings. Am J Obstet Gynecol MFM. Use of At-Home COVID-19 Tests United States, August 23, 2021March 12, 2022. MMWR Morb Mortal Wkly Rep. Mar 18 2022;71(11):429-436. doi:10.15585/mmwr.mm7111e2, Delahoy MJ, Ujamaa D, Whitaker M, et al. Clinical Presentation and Outcomes of Pregnant Women With Coronavirus Disease 2019: A Systematic Review and Meta-analysis. For those without symptoms, CDC guidance states they are considered contagious at least two days before their positive test. You will be subject to the destination website's privacy policy when you follow the link. But while it's taking less time to develop symptoms, for many people it is also taking less time to recover. Jun 2021;299(3):E262-e279. Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data. Racial and Ethnic Disparities in Receipt of Medications for Treatment of COVID-19 - United States, March 2020-August 2021. All HTML versions of MMWR articles are generated from final proofs through an automated process. CDC twenty four seven. May 2020;94:91-95. doi:10.1016/j.ijid.2020.03.017, Tenforde MW, Billig Rose E, Lindsell CJ, et al. . MMWR Morb Mortal Wkly Rep. Apr 3 2020;69(13):377-381. doi:10.15585/mmwr.mm6913e1, Sheehan MM, Reddy AJ, Rothberg MB. Lancet. Comment submitted successfully, thank you for your feedback. days (95% CI). Message not sent. Through these investments, an average of 50,00060,000 positive specimens are sequenced weekly as part of national SARS-CoV-2 genomic surveillance, which assisted with identifying initial cases of COVID-19 attributed to the Omicron variant in the United States. The estimated mean incubation period was shorter for patients during the BA.5dominant period than during the Delta-dominant period. MMWR Morb Mortal Wkly Rep. May 27, 2022 71(21):713717. Emerg Infect Dis. Statistics OfN. Shortness of breath or difficulty breathing. Clin Infect Dis. Aug 2021;69(6):1253-1255. doi:10.1136/jim-2021-001853, Roskosky M, Borah BF, DeJonge PM, et al. 2022/09/15 2022;doi:10.1007/s00431-022-04600-x, Zimmermann P, Pittet LF, Curtis N. How Common is Long COVID in Children and Adolescents? study . An update on COVID-19 and pregnancy. Clin Microbiol Infect. But some scientists who've studied Omicron and. Jama. Fourteen (33%) persons reported international travel during the 14 days preceding symptom onset or receipt of a positive test result. Euro Surveill. Jan 2021;21(1):52-58. doi:10.1016/S1473-3099(20)30764-7, Wang J, Kaperak C, Sato T, Sakuraba A. COVID-19 reinfection: a rapid systematic review of case reports and case series. European Journal of Pediatrics. Trends in Geographic and Temporal Distribution of US Children With Multisystem Inflammatory Syndrome During the COVID-19 Pandemic. Verywell Health's content is for informational and educational purposes only. A) Transmission period; B) incubation period; C) serial interval. On November 26, a Presidential Proclamation suspended entry into the United States for noncitizens (as immigrants and nonimmigrants) who were present in any of eight countries in southern Africa (Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa, and Zimbabwe) during the 14 days preceding travel to the United States. Persons exposed to SARS-CoV-2 in household, workplace, or school settings were excluded if they might have been exposed at another time. *** To date, at least one confirmed case attributed to the Omicron variant has been identified in the United States through these aircraft contact investigation efforts. endorsement of these organizations or their programs by CDC or the U.S. A number of measures have been implemented throughout the COVID-19 pandemic to reduce the introduction and spread of SARS-CoV-2 in the United States through travel. MMWR Morb Mortal Wkly Rep. Mar 25 2022;71(12):466-473. doi:10.15585/mmwr.mm7112e2, Johnson AG, Amin AB, Ali AR, et al. Genomic surveillance is implemented in partnership with state and local public health laboratories, the Association of Public Health Laboratories, and other academic and government partners. As of the week ending December 4, the SARS-CoV-2 B.1.617.2 (Delta) variant was estimated to account for 99.9% of SARS-CoV-2 circulating in the United States. A shorter incubation suggests a shorter quarantine period for BA.5 than for other variants. ThermoFisher Scientific. During the Delta-dominant period, the mean incubation period was 3.7 (3.44.0) days, and the median was 3.5 (3.23.8) days. Mar 11 2021;21(1):257. doi:10.1186/s12879-021-05950-x, Grant R, Charmet T, Schaeffer L, et al. If a pair shared meals on July 4 and the infectee had COVID-19 symptoms on July 7, we calculated an incubation period of 3 days. While long COVID, hospitalization, or death is less likely if a person is vaccinated, it is still possible and is not a risk that most of us want to take. Multisystem Inflammatory Syndrome in Adults After Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection and Coronavirus Disease 2019 (COVID-19) Vaccination. CDC twenty four seven. Clinicians should also consider advising people who are infected with COVID-19 to follow CDC guidelinesfor isolation. The mean incubation period was 2.5 days for patients infected during shared meals, 2.9 days for patients without transmission during shared meals, 3.0 days for patients with infectors who were <19 years of age, and 2.5 days for patients with infectors who were >20 years of age (2.6 days for 79 patients with infectors who were 2059 years of age and 2.1 days for 16 patients with infectors who were >60 years of age). Characteristics and Outcomes of US Children and Adolescents With Multisystem Inflammatory Syndrome in Children (MIS-C) Compared With Severe Acute COVID-19. National Institute for Communicable Diseases. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests. The 95th percentile distribution for incubation period among patients during the BA.5dominant period appeared shorter than that during the BA.1dominant period, although the difference was not statistically significant. Feb 9 2021;doi:10.1093/cid/ciab100, Singanayagam A, Patel M, Charlett A, et al. Trends in COVID-19 Cases, Emergency Department Visits, and Hospital Admissions Among Children and Adolescents Aged 0-17 Years - United States, August 2020-August 2021. Thank you for taking the time to confirm your preferences. Among people ages 60 and older, the average incubation was 7.43 days. part 46.102(l)(2); 21 C.F.R. The symptoms of the latest omicron subvariants are mostly similar to those of the earlier version of omicron. Journal of Infection. Aug 24 2022;75(1):e191-e200. The omicron variant may create mild COVID-19 symptoms and reinfect previously infected COVID-19 patients, but it could have a shorter incubation time than previous COVID-19 strains, according to a new Centers for Disease Control and Prevention report.. CDC investigates omicron variant spread. Nov 2020;2(4):100246. doi:10.1016/j.ajogmf.2020.100246, Galang RR, Newton SM, Woodworth KR, et al. Risk for Stillbirth Among Women With and Without COVID-19 at Delivery Hospitalization - United States, March 2020-September 2021. 2020/09/01/ 2020;98:180-186. doi:https://doi.org/10.1016/j.ijid.2020.06.052, Yang J, Zheng Y, Gou X, et al. COVID19 in childhood: Transmission, clinical presentation, complications and risk factors. of pages found at these sites. When Should You Get Tested After a COVID-19 Exposure? Nebraska Cases of Omicron Suggest Short Incubation Period and Possibly Milder Disease. Chest. Apr 1 2021;4(4):e215298. . Early research indicates that the newer versions may be more transmissible and more . Moreover, it is still necessary to wear a well-fitting mask and stay away from other people as much as possible for about five days after leaving isolation, experts said. The CDC states that anyone who may have been exposed to someone with . Exposure in restaurants has been shown to increase COVID-19 infection risk (14). The first U.S. case of COVID-19 attributed to the Omicron variant was detected on December 1, 2021. Clin Infect Dis. * SIG includes representatives from CDC, the National Institutes of Health (NIH), the Food and Drug Administration (FDA), the Biomedical Advanced Research and Development Authority (BARDA), the U.S. Department of Defense (DoD), the U.S. Department of Agriculture (USDA), and the U.S. Department of Health and Human Services (HHS). Headache. Characteristics, Outcomes, and Severity Risk Factors Associated With SARS-CoV-2 Infection Among Children in the US National COVID Cohort Collaborative. Jan 27 2021;72(2):340-350. doi:10.1093/cid/ciaa863, Belsky JA, Tullius BP, Lamb MG, Sayegh R, Stanek JR, Auletta JJ. MMWR Morb Mortal Wkly Rep. Aug 13 2021;70(32):1081-1083. doi:10.15585/mmwr.mm7032e1, National Center for Immunization and Respiratory Diseases (NCIRD), Post-COVID Conditions: Healthcare Providers, Decontamination & Reuse of N95 Respirators, Purchasing N95 Respirators from Another Country, Powered Air Purifying Respirators (PAPRs), U.S. Department of Health & Human Services. Clin Infect Dis. DOI: http://dx.doi.org/10.15585/mmwr.mm7050e1external icon. This decision was based on the evidence presented to the TAG-VE that Omicron has several mutations that may have an impact on how it behaves, for example . SARS-CoV-2 B.1.1.529 (Omicron) Variant United States, December 18, 2021. More information is available, Recommendations for Fully Vaccinated People, people who are up to date with their vaccines, Clinical Progression, Management, and Treatment, Alene M, Yismaw L, Assemie MA, Ketema DB, Gietaneh W, Birhan TY. Waltham, MA: ThermoFisher Scientific; 2021. Since July 2022, Omicron BA.5 has been the dominant variant in Japan (2,3). Incubation period of COVID-19 caused by unique SARS-CoV-2 strains: a systematic review and meta-analysis. Incubation periods are still just an average, and infected people may develop symptoms anytime within two to 14 days after exposure. Incubation period correlated with shared meals and adult infectors. During December 18, 2021, 22 U.S. states reported at least one COVID-19 case attributed to the Omicron variant. Therefore, isolating for five days may not be enough, even if one is asymptomatic, Weiss said. Timely case investigation and contact tracing can help ensure compliance with isolation and quarantine guidance and link persons with positive SARS-CoV-2 test results and their close contacts to testing and supportive services. Specimens that display SGTFs have a higher likelihood to be Omicron (although SGTFs are not unique to Omicron) based on a mutation (6970 deletion) that reduces S-gene target amplification in some PCR assays. Feb 2022;226(2):177-186. doi:10.1016/j.ajog.2021.08.054, Barbero P, Mugerza L, Herraiz I, et al.