Skip to Main Content
Don't have an account? Create Account
Don't have an account? Create Account

COVID-19: New Variants, Vaccine Reactions

The Centers for Disease Control and Prevention (CDC) Jan. 9 updated its guidance on new variants of SARS-CoV-2, the virus that causes COVID-19. Viruses naturally mutate over time, and two SARS-CoV-2 variants have appeared to spread easier and faster than other variants.

One variant (known as known as 20B/501Y.V1, VOC 202012/01, or B.1.1.7 lineage) was first detected in September 2020. This variant is prevalent in London and southeast England and has been detected in several other countries. CDC reports 64 COVID-19 cases from this variant in the United States, including:

  • 32 cases in California;
  • 22 cases in Florida;
  • three cases in Colorado;
  • two cases in Connecticut; and
  • one case each in Georgia, New York, Pennsylvania, and Texas.

Although this variant is more contagious than others, there is no evidence it causes more severe illness or increased risk of death. Another highly contagious variant (known as 20C/501Y.V2 or B.1.351 lineage) emerged in South Africa. This variant shares some mutations with the B.1.1.7 lineage, but it emerged independently, and there is no evidence that it causes more severe illness or increased risk of death. CDC also is monitoring a variant that emerged in Nigeria.

Public health officials are researching the new variants to determine if they are detected by currently available tests, respond to available treatment, and respond to vaccines. Experts believe the nature of the virus will enable variants to respond effectively to vaccines.

Study: More Than Half of COVID-19 Infections from Asymptomatic Individuals

CDC research published in JAMA Network Open estimates more than 50 percent of new COVID-19 infections came from people without symptoms. This research concludes that reducing transmission risk from asymptomatic people is crucial to control the spread of COVID-19. Wearing masks, social distancing, washing hands, and strategically testing people who come in frequent contact with the public can help curb the spread.

COVID-19 Vaccine Updates

CDC now tracks vaccination totals on its COVID Data Tracker. As of Jan. 11, more than 22.1 million doses were distributed in the United States, and more than 6.6 million people received their first dose.

Health care providers should report vaccine-related adverse events through the Vaccine Adverse Event Reporting System (VAERS). Patients also may self-report potential adverse events as they occur through v-safe, the agency’s new patient reporting platform.

CDC Updates Interim Clinical Conditions for mRNA Vaccine

The agency Jan. 6 updated its interim clinical conditions for messenger ribonucleic acid (mRNA) vaccine use. CDC clarified that second doses administered within four days prior to the recommended administration date — three weeks after the first dose for the Pfizer vaccine and one month after the first dose for the Moderna vaccine — are still valid.

The agency also recommended the vaccine be administered alone, with a minimum interval of 14 days before or after another vaccine. Coadministration is allowed in the case when vaccination benefits would outweigh the potential risks of coadministration or when vaccination would prevent barriers to mRNA COVID-19 vaccination.

Additionally, CDC clarified that patients who received monoclonal antibodies or convalescent plasma as part of COVID-19 treatment should defer vaccination for at least 90 days to avoid potential interference of the antibody therapy with immune responses from the vaccine. The conditions also include updated information on managing anaphylaxis at vaccination sites.

CDC Studies Allergic Reactions from Pfizer Vaccine

From Dec. 14–23, 2020, VAERS captured 21 cases of anaphylaxis after administering nearly 1.9 million first doses of the Pfizer-BioNTech vaccine nationwide, as reported in the Jan. 6 Morbidity and Mortality Weekly Report.

Nineteen of the 21 patients were treated with epinephrine, and 20 patients were discharged home or had recovered by the time the reaction was reported. Seventeen patients with anaphylaxis had a documented history of allergies or allergic reactions, including to drugs or medical products, foods, and insect stings; seven patients had experienced an episode of anaphylaxis in the past, including one after receipt of a rabies vaccine and another after receipt of an influenza vaccine. The cases occurred after receiving doses from multiple vaccine lots, and no geographic clustering of anaphylaxis cases was observed.

VAERS also identified 83 allergic reactions that were not anaphylaxis, with symptoms that appeared within zero to one day, 72 of which were considered nonferrous. Commonly reported symptoms included itching, rash, scratchiness in the throat, and mild respiratory symptoms. A history of allergic reactions was documented in 57 of these cases.

CDC Issues COVID-19 Vaccine Considerations for Pregnant People

CDC and the Advisory Committee on Immunization Practices (ACIP) released considerations for pregnant people who are considering receiving the authorized COVID-19 vaccines. Neither the Moderna nor the Pfizer-BioNTech vaccine has been studied on pregnant people, although studies are planned, and both vaccine manufacturers are monitoring people enrolled in the clinical trials who become pregnant.

However, studies show pregnant people are at increased risk of severe illness and death from COVID-19 compared with nonpregnant people. Pregnant people with COVID-19 also are at increased risk for preterm birth and other adverse pregnancy outcomes. Pregnant people should consult with their health care provider about whether to get the vaccine when it is available to them.

Visit the America’s Essential Hospitals coronavirus resource page for more information about the pandemic.

Contact Senior Director of Policy Erin O’Malley at or 202.585.0127 with questions.


About the Author

Emily Schweich is a communications manager at America's Essential Hospitals.

Previous Next
Test Caption
Test Description goes like this