COVID SCIENCE- 4th shot protects against severe Omicron outcomes; COVID may increase the risk of rare blood clots in the eye

Written by Nancy Lapid

April 14 (Reuters) – Here is a summary of some recent studies on COVID-19. They include research that requires further study to confirm results and that has not yet been approved by peer review.

The fourth vaccine dose protects against Omicron for at least one month

A fourth dose of a COVID-19 vaccine from Pfizer and BioNTech provided significant additional protection against severe illness, hospitalization and death for at least a month in older individuals, according to a study conducted in Israel when the alternative Omicron was dominant.

The estimated efficacy of the fourth dose during days 7 to 30 after administration compared to a third dose given at least four months earlier was 45% against infection, 55% for symptomatic disease, 68% for hospitalization, 62% for severe disease and 74% for mortality, it was reported. The research team reported Wednesday in the New England Journal of Medicine https://www.nejm.org/doi/full/10.1056/NEJMoa2201688. The study compared 182,122 people aged 60 or older who received a fourth dose and 182,122 very similar people who received a third but not a fourth dose.

“The results of our real-world study indicate that a fourth dose of the vaccine is, at least initially, effective against the omicron variant,” the researchers said. “Further follow-up will allow additional evaluation of the protection provided by the fourth dose over time.” A larger, recently published Israeli study https://www.nejm.org/doi/full/10.1056/NEJMoa2201570 that looked only at rates of breakthrough infection and critical illness after the fourth dose found that efficacy diminished rapidly against infection but remained stable versus severe. Illness.

COVID-19 may increase the risk of rare eye clots

New findings suggest that patients with COVID-19 may be at increased risk of rare, vision-threatening blood clots in the eye for months afterward.

Because SARS-CoV-2 infection increases the risk of blockages in blood vessels at other sites of the body, researchers studied nearly half a million COVID-19 patients to see if they would develop clots in the veins or arteries of the retina, the nerve tissue in the back of the body. The eye that receives images and sends them to the brain. Over the next six months, 65 patients had retinal vein occlusion. While that number is low, it reflects a statistically significant 54% increase over pre-COVID infection rates, according to a report published Thursday in JAMA Ophthalmology https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2790988. Retinal artery thrombosis was 35% more common after COVID-19 than before, but this difference may have been due to chance. Clots often occur in patients who have other conditions that increase their risk of blood vessel problems, such as diabetes, high blood pressure, and high cholesterol.

The risk of thrombosis does not appear to correlate with the risk of infection with the coronavirus. The researchers noted that the study could not prove that COVID-19 caused clots in the eyes of these patients, saying that larger studies on this problem are needed.

Risk of penetration infection linked to psychological problems

New data shows that people with mental health issues are more likely to get infections after receiving COVID-19 vaccines.

Researchers in California have tracked more than a quarter of a million fully vaccinated patients in the US Veterans Affairs health system. Almost all of them are men, and nearly half have received at least one psychiatric diagnosis in the past five years. Overall, 14.8% developed a COVID infection despite vaccination. Compared to study participants without a psychiatric diagnosis, those over 65 who had substance abuse, psychotic disorders, bipolar disorder, adjustment disorder or anxiety had a 24% higher risk of infection, the study found. The researchers reported Thursday in JAMA Network Open https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2791033 that for those under 65, the risk was 11% higher than for those without a psychiatric history.

“Our research suggests that the increase in penetrative infection in people with psychiatric disorders cannot be fully explained by sociodemographic factors or pre-existing conditions,” said study leader O’Donovan of San Francisco, Virginia Health Care System. “It is possible that immunity wanes after vaccination more quickly or more strongly for people with psychiatric disorders and/or may have less protection for newer variants.”

Click for a Reuters graphic https://tmsnrt.rs/3c7R3Bl on vaccines in development.

(Reporting by Nancy Lapid; Editing by Bill Bercrot)

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