Below is a summary of some recent studies of COVID-19. They include research that warrants further study to confirm the findings and has yet to be certified by peer review.
Long-term COVID risk not lower after breakthrough infection
COVID-19 vaccines are highly effective at protecting against serious illness, but they do not protect against “long-term COVID” in people who become infected despite vaccination, new data shows. For six months, researchers followed 9,479 vaccinated individuals diagnosed with COVID-19 and about the same number of infected patients who had not been vaccinated.
Compared to the unvaccinated patients, people with so-called breakthrough infections had “a much lower risk of serious complications from COVID-19,” such as needing to be admitted to an intensive care unit, receiving respiratory assistance, or developing a blood clot in their abdomen. legs or lungs, said Maxime Taquet of the University of Oxford. But other complications from the virus, including the syndrome of persistent symptoms known as long-term COVID, occurred at a similar rate regardless of vaccination status, his team said in a paper posted to medRxiv prior to peer review.
In people over age 60 with breakthrough infections, vaccines protected only weakly or not at all against COVID-19 complications, Taquet noted. “Vaccines are still an excellent way to prevent any complication of COVID-19 (including long-term COVID) because they prevent infection in the first place,” Taquet said. “However, these findings show that those who become infected despite being vaccinated should remain vigilant for potential complications of their disease.”
COVID-19 survival has improved for European cancer patients
European cancer patients who become ill with COVID-19 are now much more likely to survive than they were in the pandemic, researchers have found. They assessed the outcomes of more than 2,600 cancer patients with coronavirus infections treated in six countries between February 2020 and February 2021 to calculate death rates within the first two weeks of diagnosis.
“The first studies on the subject documented a death rate ranging from 30 percent to 40 percent… in patients with cancer,” said Dr. David James Pinato of Imperial College London. “Our study suggests that over the course of the pandemic, mortality has gradually declined, even before vaccines were implemented, to a figure that was only 12.5 percent during the so-called ‘second wave’ in Europe.”
Cancer patients diagnosed earlier in the pandemic also had more COVID-19 complications, his team reported Wednesday in JAMA Oncology. The researchers believe that the improved survival is not only related to better treatments, but also better availability of COVID-19 tests that allow for an earlier diagnosis. These factors “have been critical in improving the overall outcome,” Pinato said.
‘Glimpse of Hope’ When Drugs Limit Vaccine Antibodies
People taking a class of drugs known to limit the antibody response of Pfizer/BioNTech or Moderna’s mRNA COVID-19 vaccines may receive some protection from another part of the immune system, according to a small study published in Clinical Infectious Diseases . The class of anti-CD20 drugs used to treat rheumatoid arthritis, some cancers, and other conditions, such as Roche’s Rituxan (rituximab), suppress the immune system. But the new findings offer “a glimpse of hope” that these patients may still receive some protection from the mRNA vaccines, the study’s leader said.
The researchers studied mRNA vaccine responses in 37 patients taking these drugs for rheumatic diseases or multiple sclerosis, and compared them with 22 individuals with healthy immune systems. Only about 70 percent of the patients developed antibodies in response to the mRNA vaccines, and their levels were significantly lower than the levels in the healthy volunteers. However, both groups had equal levels of immune cells, called T cells, that could recognize and attack the coronavirus.
“Our study suggests that patients undergoing anti-CD20 treatment can elicit potent T-cell responses to mRNA COVID-19 vaccines,” the researchers wrote, despite reduced antibody responses. The size of the study “does not allow us to draw firm conclusions about protection against severe COVID-19 in these patients,” said Dr. Christiane Eberhardt of the University of Geneva in Switzerland. They “still need to be vigilant and protect themselves from contamination.”