The SARS-CoV-2 virus
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SARS-CoV-2, the novel coronavirus that causes the pneumonia-like illness COVID-19, emerged at the end of 2019. The virus spread at an alarming rate, prompting the World Health Organization to declare the outbreak a pandemic and the U.S. Department of Health and Human Services to declare a public health emergency. Use these resources to help understand COVID-19 and be proactive about prevention.

COVID-19 News and Spotlights

WHO Classifies Omicron a Variant of Concern, First U.S. Case Confirmed in California

December 1, 2021

The World Health Organization (WHO) recently classified the newly identified SARS CoV-2 variant called Omicron a Variant of Concern. Viruses are constantly changing through mutations in their genetic material, resulting in variants of the original virus. These mutations sometimes help variants spread easier, become resistant to treatment or vaccines, or can make them more harmful or deadly. According to the WHO, preliminary evidence suggests that there is an increased risk of reinfection with Omicron, and that it may spread easier.

Omicron was first reported to the WHO by South Africa on November 24, 2021. The first U.S. case was confirmed in California on December 1, 2021. The person who tested positive for Omicron was a traveler who returned from South Africa on November 22, 2021. The individual had been fully vaccinated and had mild symptoms of the infection. The CDC and state and local public health departments continue to monitor for additional cases.

Meanwhile, health officials urge the public to continue following COVID-19 prevention strategies and to take steps to protect against infection. Individuals should also get tested if they have symptoms of COVID-19 or have been in close contact with someone diagnosed with COVID-19. At least one test manufacturer has confirmed that its COVID-19 test is able to detect the new variant.

Learn more about how the CDC tracks SARS-CoV-2 variants.

World Health Organization. Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern. November 26,2021. Accessed December 1, 2021.

Centers for Disease Control and Prevention. First Confirmed Case of Omicron Variant Detected in the United States. December 1, 2021. Accessed December 1, 2021.

Radhika Anilkumar and Carl O’Donnell. Thermo Fisher says its COVID-19 tests accurately detects Omicron variant. Reuters. November 29, 2021. Accessed December 1, 2021.

FDA Authorizes Additional COVID-19 Boosters, CDC Widens Eligibility

November 23, 2021

Many more people are now eligible to receive COVID-19 booster shots that recently received authorization from the Food and Drug Administration (FDA). The extra doses of the vaccines are expected to provide additional protection for millions of Americans, reducing the risk of severe disease, hospitalization and death. 

For individuals who initially received the Pfizer-BioNTech or Moderna COVID-19 vaccine, booster doses are authorized for adults age 18 and older six months or more after their initial series of the shot.

For individuals who received the Johnson and Johnson COVID-19 vaccine, booster doses are recommended for those 18 and older who received the initial shot two or more months ago.

For details and to learn more about mix and match boosters, read the CDC recommendations and the FDA announcement.

The following table summarizes the three vaccines currently available in the U.S.

Vaccine features Pfizer-BioNTech Moderna Jansen/Johnson & Johnson
Effectiveness 91% in those age 16+; more than 89% in people with underlying conditions; 100% in children age 12 to 15 94%, more than 90% in people with underlying conditions 66% in preventing COVID-19 with symptoms; 85% in preventing severe illness
Ages approved Age 5+ Age 18+ Age 18+
Number of doses 2 doses 21 days apart 2 doses, 28 days apart 1 dose
Booster authorized For all adults age 18+ six months or more after initial vaccine series  For all adults age 18+ six months or more after initial vaccine series  For adults age 18 and older who were vaccinated two or more months ago
Most common side effects Pain at the injection site, headache, fatigue, muscle pain, chills
How they work While these different vaccines work slightly differently, they all prompt our immune systems to produce white blood cells that fight the virus. Building this immunity can sometimes cause symptoms. Our bodies keep some “memory” white blood cells so that the next time we are exposed to the virus, our immune system will remember how to fight it. For details, read the CDC’s Understanding How COVID-19 Vaccines Work


Centers for Disease Control and Prevention. (Updated November 9, 2021) Different COVID-19 Vaccines. Accessed November 23, 2021.

Mayo Clinic (Updated November 23, 2021). Comparing the differences between COVID-19 vaccines. Accessed November 23, 2021.

Two COVID-19 Tests Kits Recalled

October 20, 2021

The U.S. Food and Drug Administration (FDA) says that a recall of two COVID-19 laboratory test kits from an Abbott Laboratories unit is a Class 1 recall, the most serious type, due to the risk of false positives, which is a positive result when there is no infection. The recall is for the Alinity m Resp-4-Plex AMP and the Alinity m SARS-CoV-2 AMP test kits. In September, the FDA issued a letter warning healthcare providers and laboratories of the risk for false positive results with these two kits. The agency recommended that they consider retesting patients with a positive result from the faulty test kits with different approved COVID-19 tests. Read the full story.

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