Why does COVID-19 vary from person to person? Maybe it’s the vaccine.

While US leaders strive to prevent the spread of coronaviruses, researchers around the world are trying to answer the mystery of infectious diseases.

One of those mysteries: Why the experience can vary greatly from person to person. Some experts say the answer may involve looking at previous vaccines the individual had.

“When we looked at the condition of Covid’s disease, people who had previously been vaccinated with various vaccines, such as pneumococcus, influenza, and hepatitis, seemed to have a lower risk of developing Covid,” said Andrew Badley. I told Anderson Cooper of CNN on Monday night, an infectious disease specialist at the Mayo Clinic.

That’s what immunologists call immune training: how your immune system creates effective responses to fight infections, says Badley.

“A good analogy is to think of your immune system as muscle,” he said. “The more you exercise that muscle, the stronger it will be when you need it.”

There is no conclusive evidence of other vaccines that boost immunity to Covid-19. But Some researchers Proposed It is possible..

June, US researchers team It was proposed to boost the measles, mumps, rubella (MMR) vaccine to see if it would help prevent the most serious consequences of coronavirus infection. And last month, Researchers have found low coronavirus mortality in countries where many people are given the tuberculosis vaccine Bacillus Calmette-Guerin (BCG). This finding is consistent with other studies suggesting that vaccines can generally boost people’s immunity.

But once infected, the amount of virus that has penetrated the body can also affect the experience, another expert told CNN on Monday.

Dr Monica Gandhi, an infectious disease specialist at the University of California, San Francisco, works with a team of researchers to understand how more people experience infectious disease with minimal or no symptoms. .. About 40% of people infected with the virus No symptoms, according to estimates from the US Centers for Disease Control last month.

The Gandhi team has discovered that masks make a difference.

“What the mask does is to really reduce the amount of viruses you get when you get infected,” she said. “And by reducing it… you have a lower dose, you can manage it, you can have a mild reaction, you have a mild symptom, There are no symptoms at all.”

Doctors say they have “nothing to celebrate” about their current case levels.

To date, over 5 million Americans have Was positive At least 164,000 people were killed by the virus, according to data from Johns Hopkins University.

The average number of new cases per day in the US exceeds 54,000, exceeding 65,000 per day from mid-July to late July.

However, the average daily death rate for Covid-19 is over 1,000 for over two weeks. The country had been below that level for seven consecutive weeks before that.

“We have no plans to celebrate because we are planning 50,000 cases per day (just). Dr Rochelle Warrensky, head of the infectious disease at Massachusetts General Hospital, said on Tuesday. Has enormous morbidity and mortality.

“Even in the middle of May (like the United States) we couldn’t really control this, even 18,000 cases per day,” Walensky said.

Survey: Many Americans were not infected due to distance orders

According to a recently published modeling study, if up to 80% of Americans were infected with Covid-19, the states would not have implemented a physical distance policy.

Researchers at Harvard University and University College London have found that every state in the United States passed at least one physical distance measurement in March to delay the spread of the pandemic.

According to a study published in the magazine PLOS on Tuesday, this policy reduced more than 600,000 cases in just three weeks.

“The results show that the timing of government-issued orders was strongly correlated with both cases and reduced mortality. In short, these measures worked and policymakers in areas that did not respond to containment measures. They should be used as quiver arrows to overcome the epidemic,” said co-author Dr. Mark J. Seedner. A study by infectious disease doctors at Harvard Medical School and Massachusetts General Hospital.

According to the study, mortality was reduced by 2% per day one week after the physical separation policy began.

A sudden increase in nursing homes due to the spread of the community, the group says

Covid-19 cases have risen sharply in July in US nursing homes, following a steady decline in June, according to medical institutions, presenting serious risks to particularly vulnerable people.

The surge in nursing home cases is due to an overall surge in the population, and the US government should take steps to protect their homes, said the American Medical Association and the National Center for Living Support.

Mark Parkinson, CEO of AHCA/NCAL, told CNN on Tuesday about personal protective equipment, testing, staff support, etc. “Focusing on controlling the spread of infection within the larger community and prioritizing long-term care of resources.” It is necessary.”

The new weekly new Covid-19 cases in nursing homes decreased from 9,072 at the end of May to 5,468 by June 21, but increased to 8,628 by the week of July 19. The group cited data collected by Medicare and Medicaid Service Centers.

The report said this confirmed the fears the group had: that case would increase in nursing homes as they surged in the wider community across the country from June to July.

Older people and people with certain underlying illnesses increase the risk of serious illness CDC says..