The first was the launch of a new study nationwide in Spain, a former Covid hotspot, which suggested that too many lives would be lost while waiting to reach the approximate 60% infection rate required for collective immunity, so Many people become immune to the disease that is effectively eliminated.
The second was a report from New York, suggesting that herd immunity had already been achieved in some communities, and a health care clinic reported that just over 68% of the Covid tests performed had tested positive.
But we waste critical time with this pointless discussion, because the facts are already quite clear: collective immunity will probably never be achieved for Covid-19 or any other coronavirus. We know this thanks to new research on the development and decline of antibodies to Covid and a large body of epidemiological evidence on coronaviruses as a whole.
While SARS and MERS are the headline coronaviruses, there are four other mostly unknown coronaviruses that are much more common: 229E, HKU1, NL63, and OC43. What we know from 60 years of research on these viruses is that they return year after year and reinfect the same people, over and over again.
A study from New York City, conducted between fall 2016 and spring 2018, showed that people could test positive multiple times for infection with the same coronavirus strain, in the same year.
Antibodies to the virus would rise sharply after infection and peak after approximately two weeks. But then its presence would diminish, generally disappear entirely somewhere between four months and a year. In one case, one person was reinfected with the same coronavirus strain after just four weeks from the first infection.
Previous studies showed that the same strain of a coronavirus that causes a cold one year can do so again the following year. Unlike influenza viruses, which mutate frequently and often infect us with new strains each year, the coronavirus does not need to change to re-infect itself. Recent data suggests that SARS-CoV-2 follows the same pattern. After infection and recovery, all antibodies to the virus begin to rapidly disappear, including those that may be protective.
Over the past weekend, researchers in the UK released new research suggesting that SARS-CoV-2 does act as its most common cousins. They studied the presence of neutralizing antibodies, the specific antibodies needed to fight reinfection, and found that a transient neutralizing antibody response was “a feature shared by both a SARS-CoV-2 infection that causes low disease severity and the circulating seasonal season. ” coronaviruses that are associated with common colds. “
Essentially, the amount of neutralizing antibodies to SARS-CoV-2 in the body varies depending on the severity of the infection and the time since infection, and the longer it passes, the fewer antibodies a person retains.
This really reflects the results of the Spanish study published in The Lancet on July 6 and provides even more evidence to support the argument. The study included more than 61,000 people who received two different types of antibody tests in three separate waves from April to June.
While the study itself focused only on the results of the first wave of testing, the critical findings from the second and third waves were revealed in a public announcement the same day.
Those findings show that 7% of participants who tested positive for antibodies in the first phase of the test, conducted between April 27 and May 11, no longer had those antibodies in the second phase, which started just one week. then on May 18 and lasted two weeks.
In the third wave of testing, which started three weeks after the start of the second wave, 14% of those who tested positive for antibodies originally tested negative.
The findings support previous findings from two smaller studies conducted in China, which showed that the antibodies of those infected decrease rapidly. In one of these studies, neutralizing antibodies decreased significantly in just two months.
Not only do antibodies to SARS-CoV-2 fade, and perhaps fade quickly, studies have also shown that only 15% of those who test positive for antibodies produce the neutralizing antibodies necessary to develop immunity in the first place. And not everyone who produces neutralizing antibodies produces them at high levels. Some of those infected do not produce antibodies at all.
The body’s T cell response may also be an important factor in immunity, but it will not be the answer. T cells help our immune system by killing infected cells and activating other immune cells to fight infection. We know that people produce robust and sometimes long-lasting T-cell responses to the cold caused by coronaviruses.
Although the T cell response may be important in clearing the infection, it is clear that it does not prevent reinfection, which occurs regularly with the most common coronaviruses.
These are not one of the virus types. No natural immunity in the herd is likely to prevent SARS-CoV-2 from spreading on its own, neither now nor ever. This is not a cause for dismay, but rather a call to action; It will be by our own hand that we stop the spread of this disease.
Not all actions that can combat this disease are within the reach of the average American: the work being done in laboratories here in the United States and around the world to develop vaccines and medications to prevent and treat infections is a major source of hope to end the pandemic
And while we wait for a medical solution, government action and strong national leadership have been shown to work to control the outbreaks.
But every American also has a role to play and an opportunity to end this disease. By wearing masks, practicing safe social distancing, and choosing the drawback of self-isolation when we fear we have been exposed to infection, we can stop this outbreak in its tracks.
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