COVID-19 Vaccine Breakthrough Infections Reported to CDC — United States, January 1–April 30, 2021

Abstract

vaccines are a critical tool for controlling the ongoing global pandemic. The Food and Drug Administration (FDA) has issued Emergency Use Authorizations for three COVID-19 vaccines for use in the United States.* In large, randomized-controlled trials, each vaccine was found to be safe and efficacious in preventing symptomatic, laboratoryconfirmed . Despite the high level of vaccine efficacy, a small percentage of fully vaccinated persons (i.e. received all recommended doses of an FDA-authorized COVID-19 vaccine) will develop symptomatic or asymptomatic infections with SARS-CoV-2, the virus that causes .CDC is working with state and territorial health departments to investigate SARS-CoV-2 infections among persons who are fully vaccinated and to monitor trends in case characteristics and SARS-CoV-2 variants identified from persons with these infections. For this surveillance, a vaccine breakthrough infection is defined as the detection of SARS-CoV-2 RNA or antigen in a respiratory specimen collected from a person ≥14 days after receipt of all recommended doses of an FDAauthorized COVID-19 vaccine. State health departments voluntarily report vaccine breakthrough infections to CDC. † When possible, genomic sequencing is performed on respiratory specimens that test positive for SARS-CoV-2 RNA (9). A total of 10,262 SARS-CoV-2 vaccine breakthrough infections had been reported from 46 U.S. states and territories as of April 30, 2021. Among these cases, 6,446 (63%) occurred in females, and the median patient age was 58 years (interquartile range = 40-74 years). Based on preliminary data, 2,725 (27%) vaccine breakthrough infections were asymptomatic, 995 (10%) patients were known to be hospitalized, and 160 (2%) patients died. Among the 995 hospitalized patients, 289 (29%) were asymptomatic or hospitalized for a reason unrelated to COVID-19. The median age of patients who died was 82 years (interquartile range = 71-89 years); 28 (18%) decedents were asymptomatic or died from a cause unrelated to COVID-19. Sequence data were available from 555 (5%) reported cases, 356 (64%) of which were identified as SARS-CoV-2 variants of

Clinical Characteristics of Hospitalized COVID-19 Patients Who Received at Least One Dose of COVID-19 Vaccine

“…During the same period, the share of partially and fully vaccinated individuals in the Polish population reached 36.1 and 18.5%, respectively. This further reassures the high efficacy of the COVID-19 vaccines, in preventing severe disease, and, in line with large real-world observations, indicates that, to date, severe breakthrough infections (i.e., identified >14 days after receipt of all recommended doses) are sporadic [ 22 , 23 ].…”

Vaccination strategies for a seasonal epidemic: a simple SIR model

“…But even this estimate sounds rather cautious. The recent data of the CDC, based on more than 100 million vaccinations in the US, reported [18] around 10 thousand breakthrough infections, corresponding to an order of magnitude larger vaccine efficiency compared to that obtained from the Israel data.…”

Vaccine against COVID-19

“…En efecto, para que esta protección se produzca es por lo tanto necesario que una gran parte de la población esté vacunada (padecer la infección no es una alternativa, dados los efectos e incluso la mortalidad de ello) [182,183]. En Estados Unidos con un número de vacunados completamente frente al COVID-19 de más de 100 millones de personas se han detectado casos de la infección en más de 10.000 de estos vacunados, casos que deben esperarse, especialmente hasta que la vacunación alcance los niveles suficientes para disminuir la transmisión [184].…”