Teenage girl receives Pfizer vaccine booster dose from healthcare professional wearing mask and gloves

COVID-19 Updates: ‘Vaccine’ Selected as Word of the Year, FDA Expands EUA for Pfizer Vaccine Booster, and More

Teenage girl receives Pfizer vaccine booster dose from healthcare professional wearing mask and gloves

Diagnosis tracker

Nearly 271 million cases of coronavirus (COVID-19) have been diagnosed worldwide as of Monday evening, December 13, 2021, including more than 5.3 million deaths. Healthcare officials in the United States have reported nearly 51 million positive COVID-19 cases and more than 818,000 deaths. Source: www.worldometers.info/coronavirus 

Vaccine tracker

At least 8.47 billion individual doses of COVID-19 vaccine have been administered worldwide as of Monday afternoon, including at least 484 million in the United States. Source: GitHub

Vaccine: The word of the year

One year after selecting “pandemic” as its Word of the Year for 2020, the staff at Merriam-Webster has chosen “vaccine” as the Word of the Year for 2021.

According to representatives at Merriam-Webster, interest in the definition of the word “vaccine” has been intense during the past year. Lookups for the word increased 601% year-over-year from 2020.

Interest in the word has been high since the beginning of the COVID-19 pandemic. In a recent public announcement, Merriam-Webster also stated that prominence of the word compared to 2019 shows an increase in lookups for “vaccine” of 1,048%. Lookups specifically jumped by 535% in August, when discussions about policy, approval, and vaccination rates became more common.

Derived from the Latin word vacca, or “cow,” the word “vaccine” is a relatively recent addition to the English language. Originating in the 1800s, the term was initially used to refer to inoculation against smallpox using small doses of cowpox.

According to Merriam-Webster, the definition, which formerly read “a preparation of killed microorganisms, living attenuated organisms, or living fully virulent organisms that is administered to produce or artificially increase immunity to a particular disease,” was replaced with the following: “a preparation that is administered (as by injection) to stimulate the body’s immune response against a specific infectious agent or disease.”

Related: Population Health: Contemporary Perspectives for Nurses

FDA expands emergency use of Pfizer vaccine booster

The U.S. Food and Drug Administration (FDA) has expanded the scope of its Emergency Use Authorization (EUA) of the booster dose of the Pfizer-BioNTech vaccine to include individuals ages 16 years and older. The booster dose is to be administered at least six months after completion of the primary series and is the same formulation and dosage strength as the doses in the primary series, according to Pfizer officials.

“[The] decision by the FDA to further expand the Emergency Use Authorization of a booster dose of our COVID-19 vaccine is a critical milestone as we continue to stay vigilant in addressing the virus,” said Albert Bourla, chairman and chief executive officer at Pfizer. “While new variants, including Omicron, emerge across the globe, we believe that the best way to minimize the spread of COVID-19 and any future variants is getting all eligible people fully vaccinated with the first two-dose series and a booster dose as recommended.”

A booster dose of the vaccine was previously authorized for emergency use after completion of a primary series in individuals ages 18 years and older, as well as for eligible individuals who have completed primary vaccination with a different authorized vaccine.

Pfizer and BioNTech officials said they plan to submit a supplemental Biologics License Application (sBLA) for approval of a booster dose of the vaccine in individuals ages 16 years and older. The sBLA will include efficacy and safety data from a Phase 3 trial showing that a 30-µg booster dose administered to individuals ages 16 years and older who previously received the primary two-dose series demonstrated a relative vaccine efficacy of 95% when compared to those who did not receive a booster.

These are the first efficacy data disclosed from any randomized, controlled COVID-19 vaccine booster trial. The adverse event profile was generally consistent with other clinical safety data for the vaccine, with a favorable safety profile.

Pfizer and BioNTech continue to supply the vaccine under the existing supply agreement with the United States government, which continues through April 2022. The companies do not expect the expanded EUA will impact existing supply agreements in place with governments and international health organizations around the world.

Related: Staying Healthy: Vaccine Preventable Diseases

AstraZeneca’s combo drug receives emergency use authorization

Patients with compromised immune systems and those with a history of allergies to ingredients in the existing COVID-19 vaccines now have another option against the virus.

The U.S. Food and Drug Administration has issued an emergency use authorization (EUA) for Evusheld (tixagevimab co-packaged with cilgavimab and administered together) by AstraZeneca for the prevention of COVID-19 for those ages 12 years and older who meet certain conditions:

  • Patients must not currently be infected with the virus and have not recently been exposed to an individual infected with the virus.
  • Patients must have moderately to severely compromised immune systems due to a medical condition or to taking immunosuppressive medications or treatments, and may not mount an adequate immune response to COVID-19 vaccination (examples of such medical conditions or treatments can be found in a fact sheet for health care providers).
  • Patients must have a history of severe adverse reactions to a COVID-19 vaccine and/or component(s) of those vaccines.
  • Patients must weigh at least 40 kilograms (about 88 pounds).

“There are certain immune-compromised individuals who may not mount an adequate immune response to COVID-19 vaccination, or those who have a history of severe adverse reactions to a COVID-19 vaccine, and therefore cannot receive one and need an alternative prevention option,” said Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research.

One dose of Evusheld, administered as two separate consecutive intramuscular injections (one injection per monoclonal antibody, given in immediate succession), could be effective for pre-exposure prevention for six months, according to the FDA.

Pre-exposure prevention with Evusheld is not a substitute for vaccination in individuals for whom COVID-19 vaccination is recommended. The FDA has approved one vaccine and authorized others to prevent COVID-19 and serious clinical outcomes associated with a COVID-19 infection, including hospitalization and death.

Tixagevimab and cilgavimab are long-acting monoclonal antibodies that are specifically directed against the spike protein of the virus, designed to block the virus’ attachment and entry into human cells. Tixagevimab and cilgavimab bind to different, non-overlapping sites on the spike protein of the virus.

The primary data supporting this EUA are from a randomized, double-blind, placebo-controlled clinical trial in adults older than 59 years or with a pre-specified chronic medical condition, or at increased risk of infection for other reasons who had not received a COVID-19 vaccine and did not have a history of infection or test positive for infection at the start of the trial.

The main outcome measured in the trial was whether a trial participant had a first case of COVID-19 after receiving Evusheld or placebo and before day 183 of the trial. In this trial, 3,441 people received Evusheld and 1,731 received a placebo.

In the primary analysis, Evusheld recipients saw a 77% reduced risk of developing COVID-19 compared to those who received a placebo. In additional analyses, the reduction in risk of developing COVID-19 was maintained for Evusheld recipients through six months. The safety and effectiveness of Evusheld for use in the pre-exposure prevention of COVID-19 continue to be evaluated, according to the FDA.

Possible side effects of Evusheld include: hypersensitivity reactions (including anaphylaxis), bleeding at the injection site, headache, fatigue and cough. Serious cardiac adverse events were infrequent in the trial.

However, more trial participants had serious cardiac adverse events (such as myocardial infarction and heart failure) after receiving Evusheld compared to placebo. These participants all had risk factors for cardiac disease or a history of cardiovascular disease before participating in the clinical trial. It is not clear if Evusheld caused these cardiac adverse events.

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