New heart problems discovered post COVID-19; virus mutation may make vaccines more effective

More than three-quarters of recently recovered coronavirus disease 2019 (COVID-19) patients had heart muscle problems show up during magnetic resonance imaging (MRI) tests, German doctors reported on Monday in JAMA Cardiology.

In some patients, the heart may be "in serious trouble as a part of COVID-19 disease," Dr. Valentina Puntmann of University Hospital Frankfurt told Reuters.

Among 100 patients ages 45 to 53, "a considerable majority" - 78 - had inflammation in the heart muscle and lining.

Sixty-seven had recovered at home while 33 had required hospitalization. Half of the former patients were more than two months out since their diagnosis at the time of the MRI.

Thirty-six patients reported ongoing shortness of breath and general exhaustion, and 71 had blood markers of heart muscle damage.

Compared with similar people who had not had COVID-19, the recently recovered patients' hearts pumped more weakly and displayed other risk factors for heart failure. Puntmann suspects the abnormalities are signs of permanent problems.

"While we do not have direct evidence for late consequences yet, such as the development of heart failure ... it is quite possible that in a few years, this burden will be enormous based on what we have learned from other viral conditions that similarly affect the heart," she said.

Mutation may have made virus more vulnerable to vaccines

A genetic mutation that made the new coronavirus more infectious may also make it more vulnerable to vaccines, researchers believe.

The mutation, designated D614G, increases the number of "spikes" on the surface of the virus and makes them more stable, allowing the virus to more efficiently break into and infect cells.

The mutation will not pose problems for vaccines now in clinical trials, however, because the extra spikes retain the targets for the "neutralizing antibodies" the vaccines are designed to induce.

Those targets, called receptor-binding domains, or RBDs, are the places where the spike attaches itself to the cells it infects. With more spikes, there are more RBDs for the antibodies to bind to in order to neutralize the virus.

"The gain in infectivity provided by D614G came at the cost of making the virus more vulnerable to neutralizing antibodies," the researchers wrote in a paper posted on medRxiv on Friday ahead of peer review. -- Reuters