New Delhi: Amid the US leaders working hard to combat the fast spread of COVID-19, the researchers across the globe are working to answer the mysteries that remain around infections.
One of those mysteries: why the experience can be so different from person to person. One expert says the answer may involve looking at previous vaccines individuals have had.
“When we looked in the setting of Covid disease, we found that people who had prior vaccinations with a variety of vaccines — for pneumococcus, influenza, hepatitis and others — appeared to have a lower risk of getting Covid disease,” Dr. Andrew Badley, an infectious disease specialist at Mayo Clinic said.
It’s what immunologists call immune training: how your immune system creates an effective response to fight off infections, Badley says.
“A good analogy is to think of your immune system as being a muscle,” he said. “The more you exercise that muscle, the stronger it will be when you need it.”
There’s been no definitive evidence of any other vaccines boosting immunity against Covid-19. But some researchers have suggested it’s possible.
In June, a team of researchers in the US proposed giving a booster dose of the measles, mumps and rubella (MMR) vaccine to people to see if it helps prevent the most severe effects of coronavirus infections.
And last month, researchers found that countries where many people have been given the tuberculosis vaccine Bacillus Calmette-Guerin (BCG) had less mortality from coronavirus, a finding that fits with other research suggesting the vaccine can boost people’s immunity in general.
But once you’re infected, how much of the virus made it into your body could also have an impact on what your experience is, another expert said.
Dr. Monica Gandhi, an infectious disease specialist at University of California, San Francisco, has been working with a team of researchers to understand how more people could go through their infections with minimal or no symptoms.
About 40% of people infected with the virus don’t have symptoms, according to an estimate last month by the US Centers for Disease Control and Prevention.
“What the mask does is really reduce the amount of virus that you get in, if you do get infected,” she said. “And by reducing that … you have a lower dose, you’re able to manage it, you’re able to have a calm response and you have mild symptoms or no symptoms at all.”
‘We have nothing to celebrate’ about current case levels, physician says So far, more than 5 million Americans have tested positive for the virus and at least 164,000 have died, according to Johns Hopkins University data.
The average number of daily new cases in the US is more than 54,000, down from more than 65,000 per day in mid- to late-July.
Average daily Covid-19 deaths, however, have hovered above 1,000 for more than two weeks. The country had been below that level for seven consecutive weeks before that.
“We have nothing to celebrate (just) because we’re going to 50,000 cases per day. We have a huge amount of morbidity and mortality at our feet right now and in the weeks ahead,” Dr. Rochelle Walensky, chief of infectious diseases at Massachusetts General Hospital, said.
“Even at 18,000 cases per day (as the US had) in mid-May, we were unable to really squelch this,” Walensky said.
