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

COVID-19: Vaccine Effectiveness; Pfizer, Moderna Request EUA for Fourth Shot

A new study in the Centers for Disease Control and Prevention’s (CDC’s) Morbidity and Mortality Weekly Report highlights the effectiveness of COVID-19 messenger ribonucleic acid (mRNA) vaccines in preventing invasive mechanical ventilation (IMV) and death.

Using surveillance data from the Influenza and Other Viruses in the Acutely Ill (IVY) Network, the study shows receiving two or three doses of an mRNA COVID-19 vaccine was associated with a 90 percent reduction in risk for COVID-19–associated IMV or death. During the period of omicron variant predominance, receipt of three mRNA vaccine doses was associated with a 94 percent risk reduction.

Pfizer, Moderna Seek EUA for Additional Booster Dose

Pfizer Seeks EUA for Adults Aged 65 and Older

Pfizer and BioNTech on March 15 applied for Food and Drug Administration (FDA) emergency use authorization (EUA) of an additional COVID-19 vaccine dose for adults aged 65 and older who received an initial dose of any authorized or approved COVID-19 vaccine. In their application, Pfizer and BioNTech cited two datasets from Israel.

In an analysis of Israeli Ministry of Health records for more than 1.1 million adults aged 60 and older without a history of SARS-CoV-2 who were eligible for a fourth dose booster. Rates of confirmed SARS-CoV-2 infection were two times lower and rates of severe illness were four times lower among individuals who received an additional booster dose of the Pfizer-BioNTech vaccine administered at least four months after an initial booster dose, compared to those who received only one booster dose.

Additionally, an ongoing, open-label, nonrandomized clinical trial in health care workers aged 18 and older shows that neutralizing antibody titers increased seven-to-eightfold at two and three weeks after receipt of an additional booster, compared with five months after receiving the initial booster dose. Neutralizing antibody titers against the omicron variant of SARS-CoV-2 increased eightfold one week after receiving the dose and tenfold after two weeks.

Pfizer and BioNTech received approval for their vaccine in August 2021 and a booster EUA in September 2021.

Moderna Seeks EUA for Adults Aged 18 and Older

Moderna on March 17 also filed for an EUA for a fourth dose booster of its COVID-19 vaccine. Unlike Pfizer and BioNTech, Moderna seeks authorization for all adults aged 18 and older. The company seeks to give CDC flexibility to determine the appropriate use of a fourth vaccine dose, considering age or comorbidities.

Moderna received FDA approval for its primary dose series in January 2022 and a booster EUA in October 2021.

FDA Advisory Committee to Discuss Boosters

FDA announced a virtual meeting of its Vaccines and Related Biological Products Advisory Committee (VRBPAC) on April 6 to discuss considerations for future COVID-19 vaccine booster doses.

The VRBPAC is intended to assist the agency in developing a general framework that will inform its regulatory decision-making on what might warrant updating the composition of COVID-19 vaccines to address specific variants and timing and populations for COVID-19 vaccine booster doses in the coming months.

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.

where to buy viagra
buy lasix
buy doxycycline
buy trazodone
buy famvir
buy metoprolol
where to buy methylprednisolone
where to buy disulfiram
canadian pharmacy
buy albuterol inhaler
buy cialis online
prednisone otc
where to buy accutane
buy abilify
buy domperidone
buy neurontin
where to buy zithromax online
buy synthroid
ivermectin otc
buy strattera online
metformin otc
clomid online
nitrofurantoin otc
online drugstore
where to buy flagyl
where to buy diflucan
mexican pharmacy
misoprostol online
discount pharmacy
buy zoloft online
citalopram online
hydroxyzine online
kaletra online
Previous Next
Test Caption
Test Description goes like this