Immunity

This CDC investigation of an outbreak in the enclosed environment of a ship suggests high vaccination rates, in combination with COVID-19 prevention measures, can substantially reduce the spread of SARS-CoV-2.

During Omicron-predominant period, vaccine effectiveness against COVID-19–associated emergency department/urgent care visits and hospitalizations had decreased by the fourth month after a booster dose, according to this CDC MMWR.

CDC MMWR on finding that compared with patients during the Delta wave, Omicron-period COVID-19 patients had less severe illness, largely driven by an increased proportion who were fully vaccinated.

CDC MMWR on finding that protection against infection and death during the Delta wave and against infection during Omicron emergence was higher among booster recipients.

According to this CDC MMWR, between May and November 2021, people who were unvaccinated and did not have a prior COVID-19 infection remained at the highest risk of infection and hospitalization; those previously infected, with or without prior vaccination, had the greatest protection.

CDC MMWR on effectiveness of vaccines in preventing hospitalizations for COVID-19 among U.S. veterans, indicating boosters play an important role in protecting against severe COVID-19.

A new CDC study shows vaccination provides greater protection against COVID-19 than a prior infection.

Study of UK data published in The Lancet showing that vaccination against COVID-19 reduced odds of hospitalization or having symptoms of the virus in cases of breakthrough infections.

This NIH Director’s Blog highlights evidence that protective antibodies generated in response to an mRNA vaccine will target a broader range of SARS-CoV-2 variants carrying “single letter” changes in a key portion of their spike protein compared to antibodies acquired from an infection.

Breakthrough COVID-19 infections occur in only a small fraction of all vaccinated people and account for a small percentage of U.S. cases, and CDC has transitioned from monitoring all reported breakthrough infections to investigating only those among patients who are hospitalized and/or die, according to this MMWR.

Among 627 people with SARS-CoV-2 infection across 75 SNFs since vaccination clinics began, 22 infections were identified among 12 residents and 10 staff members across 15 facilities ≥14 days after receiving their second vaccine dose (i.e., breakthrough infections in fully vaccinated persons), according to this CDC MMWR.

CDC summary of evidence and additional considerations used to inform public health recommendations for fully vaccinated people.

An expert overview published in Immunity describing the basic concepts of herd immunity and implications during the pandemic.

JAMA Insight on herd immunity and its implications during COVID-19.

Commentary published in The Lancet Infectious Diseases summarizes four cases that show evidence of COVID-19 reinfection and outlines questions to guide further research.

Article in Clinical Infectious Diseases describing a previously infected Dutch patient who showed COVID-19 symptoms again following chemotherapy.

In this recording, experts discuss using transcriptomics to study the host-pathogen interaction during infection, describe characterization of the immune response to infection and/or vaccination, and explain how to assess the impact of SARS-CoV-2 variants of concern.

Patient-facing JAMA article that includes an infographic.