Can herd immunity help stop coronavirus? What we know now

Since the Corona virus The pandemic started, the term “herd immunity” was hurled around as a solution to the devastating virus devastating countries around the world since December 2019. The term explains the situation in which a high percentage of people in a particular community (city, state or whole country) are immune to a disease, either through vaccination or because these people are infected by the virus and its diseases The immune system has built up antibodies to protect them from them. People who advertise it as the best Defense against SARS-CoV-2, the virus that causes COVID-19, are right in their thinking – it is the best way to prevent infectious diseases from circulating in a population because it slows or eliminates the spread of the virus from person to person.

The problem with herd immunity and the novel coronavirus is that the world is far from having widespread resistance to COVID-19 and is still far from developing. Experts estimate that 60% to over 90% a population must have immunity to a disease so that it no longer spreads. Most countries affected by COVID-19 have not exceeded the 1% mark. including the United Stateswho currently has that highest number of cases in all countries.

Let’s examine what herd immunity looks like, what it means for COVID-19, and how the world can get there, Dr. Jane Orient, managing director of American Association of Physicians and Surgeons, Dr. Joseph Vinetz, a specialist in infectious diseases at Yale Medicine, and centers for disease control and prevention.

What is herd immunity?

Dr. Orient tells CNET that herd immunity slows outbreaks and epidemics and ultimately stops them – this only occurs “when the pathogenic organism runs out of vulnerable victims as a result isolation, quarantine or immunity of exposed persons. “

Dr. Orient, who says that she really prefers the term “immunity of the population” because “we are not cattle”, insists: “If there were no immunity for the population … we would all die like the Martians in the war of the population . ” Worlds. “In the famous story by H.G. Wells, all Martians who travel to Earth die from earth-borne pathogens against which the Martians’ immune system could not fight.

Dr. Vinetz from Yale Medicine explains that measles is a good example of herd immunity. “The idea is that if we have herd immunity, it means that we are reducing the transmission of an illness within a population,” says Dr. Vinetz. “The best example to think of is measles. If 95% of all people are vaccinated against measles, it means that 95% are immune to measles, which means that the risk of measles spreading from person to person is very high is low. “

The goal, says Dr. Vinetz, is to rule out the possibility of sustainable transmission. To get to this point, the vast majority of people in a particular town, city, state, or country would need it immunity. To do this, these people must either become infected with the disease and recover from it, or be vaccinated against the virus.

While “active immunity” – immunity that a person builds up in response to the actual infection with a disease – is the most effective and long-lasting, Experts ask people not to deliberately become infected with SARS-CoV-2 in an attempt to build immunity. That leaves us with the other option: a vaccine.

How vaccines promote herd immunity

The purpose of vaccines, says Dr. Orient is to “expose people to something that induces immunity without making them very sick” and to explain that vaccines are either tiny doses of a pathogen, a dead microorganism, or a microorganism that is similar but weaker.

“You need more than 70% of the protective immunity in a population to prevent large-scale proliferation,” explains Dr. Vinetz. This often requires immunization, especially for diseases that have almost been eradicated in the United States.

Dr. Vinetz again refers to measles as the best example of this. With a highly effective vaccination, most commonly referred to as measles, mumps and rubella or MMR shot, this is easy to prevent.

But in 2019, the U.S. saw that highest number of measles cases since 1992and most of the cases concerned people who were not vaccinated against measles. The 1,282 measles cases in 2019 fade compared to an estimated 3 to 4 million cases per year before the introduction of the vaccine, which provides strong evidence that vaccines are highly effective in reducing the incidence or elimination of disease in a region.

Only one disease – Variola virus, better known as smallpox – has been completely eradicated. No cases of naturally occurring smallpox have occurred since the declaration of eradication in 1980, and babies no longer need the vaccine for this virus because of the global vaccination program was so successful.

“The disease rates in the United States are low today,” said the CDC explains on its website. “But if we make ourselves vulnerable by not vaccinating, a case that could trigger an outbreak of a disease that is currently under control is only a flight away.”

The development and approval of vaccines requires careful analysis of the benefit-risk balance, says Dr. Orient. “With extremely contagious, deadly diseases such as smallpox, the risk-benefit ratio for vaccines is very favorable,” she says. “Not necessarily with milder illnesses.”

Vaccines can also have adverse effects in some people, and immunity will decrease over time. Therefore, the importance of vaccination depends on a number of factors, including disease severity and prevalence, vaccine safety, and individual patient factors, explains Dr. Orient. “Everything is a compromise,” she says.

Dr. Orient asks people not to forget that vaccines, although crucial for some diseases, are not the only way to prevent diseases: “Diseases are also prevented by hygiene, hygiene, vector control (e.g. mosquito control) or Healing the sick previously prevented disease can be transmitted. ”

Why we need herd immunity

If there is no herd immunity, people will continue to develop and spread diseases, and unfortunately people will continue to die from these diseases. The CDC defines herd immunity or Community immunityas “a situation in which a sufficient proportion of a population is immune to an infectious disease (through vaccination and / or previous illness) to make it unlikely to spread from person to person.

“Even non-vaccinated people (such as newborns and those with chronic illnesses) are offered some protection,” continues the CDC, “since the disease can hardly spread in the community.”

SARS-CoV-2, the virus that causes COVID-19, is a hauntingly relevant example. This virus is new to humans, so no one had immunity to it, either natural or vaccinated, when it first infected humans. Because nobody has immunity and the virus is contagious, it is spreads quickly and easily.

What does it take to have immunity to coronavirus herds?

There are two ways to establish herd immunity to a disease: develop and administer a safe and effective vaccine, or wait for the disease to circulate in a population.

A Vaccination against SARS-CoV-2 is in progress, but it will likely take more than a year for the vaccine to become public. Much of the United States is currently without a vaccine Shelter and social distancing orders to wait for it to develop or for people to get the disease and recover from it to create herd immunity.

However, too many important factors are unknown to simply allow the virus to continue its killing spree without intervention:

• Scientists don’t know if humans can get the SARS CoV-2 virus more than once.
• Nobody knows whether a positive coronavirus antibody test means that you are immune to the infection or spread of the virus.
• Research on COVID-19 treatment is ongoing and there is no finite treatment.
• Much of the population is at risk of serious complications that can lead to death. But young, healthy people can also develop complications that lead to death, which raises questions about the nature of the virus.
• It is impossible to know how many people had the virus and did not report their case, either because they were asymptomatic or did not feel sick enough to be tested, or because no test was available.

Dr. Vinetz believes the US is nowhere near herd immunity to the novel coronavirus: “If we have 330 million people in the US and 1% are infected, that will be 3.3 million people, and that always means yet that 99% of the US population remains vulnerable. ”

If you agree with Dr. Vinetz believes that at least 70% of the population must be immune to a disease to cause herd immunity, it means at least 231 million people in the United States need to contract and recover from the disease.

The actual number of COVID-19 cases in the U.S. had not reached 1% of the population by April 16 – you can Follow the cases across the U.S. on the CDC websitethat is constantly updated. “Einstein doesn’t have to find out that we are nowhere near herd immunity,” says Dr. Vinetz.

When do we have immunity to coronavirus herds?

Whether we will see herd immunity to SARS-CoV-2 in the future depends heavily on a number of factors – in particular, says Dr. Orient whether we allow people to move or not. “If we keep everyone in solitary confinement, they won’t become immune unless and until there is an effective vaccine,” she explains. “With some diseases like the common cold (coronaviruses are a cause) there is not much herd immunity because the virus changes or the vaccine just doesn’t work malaria. “

When asked about localized herd immunity or herd immunity in certain regions with a high number of coronavirus cases (such as New York and California), Dr. Vinetz that the concept is not really important when people are allowed to walk around.

“We are such a mobile society,” he says Orders stay at home relaxed or distant, “when people start getting on buses, planes, and trains and visiting other areas,” localized herd immunity means nothing.

It’s all very complicated, that’s the point.

Dr. Vinetz says he expects “continuously rolling waves from [COVID-19] Infection unless we intervene somehow “to destroy the idea that SARS-CoV-2 will increase sharply again in the fall of 2020 simply because it is unlikely to have subsided or disappeared at that point. Unfortunately, this means that we’ll probably do it. ” Wait until 2020 and until 2021 to achieve herd immunity.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a doctor or other qualified healthcare provider if you have any questions about an illness or health goals.