Featured Fitness Sleep Healthy Eating Caregiving Personal Care Can herd immunity help stop coronavirus? What we know now -- How herd immunity happens and what that means for the novel coronavirus. -- -- gettyimages-1226216281 Herd immunity occurs when the vast majority of people in a geographic region are immune to a disease, eventually stopping its spread. Getty Images -- -- pandemic, visit the WHO website. Six months into the COVID-19 crisis, the term "herd immunity" has been tossed around as one solution to the devastating virus ravaging countries all over the globe since December 2019. -- -- from person to person. The problem with herd immunity and the novel coronavirus is that the world is nowhere close to having widespread resistance to COVID-19, and is still a long way from developing it -- even after six months of -- -- is still a long way from developing it -- even after six months of battling out this pandemic. Experts estimate that from 60% to upwards of 90% of a population must have immunity to a disease for it to stop spreading. -- -- Even as of July 2020, as cases have topped 15.3 million worldwide (and 4 million in the US), herd immunity isn't anywhere close. For reference, the US population is about 330 million -- 90% of that is 297 million. One factor standing in the way of reaching that 90% is that -- -- large-scale coronavirus research has suggested that people who have recovered from the virus aren't retaining their antibodies, which could mean that herd immunity is farther away than anyone thinks. IFRAME: https://playlist.megaphone.fm?e=CBS6898297654&light=true -- -- IFRAME: https://playlist.megaphone.fm?e=CBS6898297654&light=true Let's explore what herd immunity looks like, what it means for COVID-19 and how the world can get there, explained by Dr. Jane Orient, executive director of the American Association of Physicians and -- -- 6:02 What is herd immunity? -- Orient tells CNET that herd immunity is what slows and eventually stops outbreaks and epidemics -- this occurs only "when the pathogenic organism runs out of susceptible victims because of isolation, -- -- outbreaks and epidemics -- this occurs only "when the pathogenic organism runs out of susceptible victims because of isolation, quarantine or immunity of exposed persons." -- Orient -- who says she really prefers the term "population immunity" because "we are not livestock" -- emphatically points out that "If it -- because "we are not livestock" -- emphatically points out that "If it weren't for population immunity … we'd all die like the Martians in The War of the Worlds." In the movie, the Martians who travel to Earth all die from an Earth-borne bacteria that the Martians' immune systems -- -- couldn't handle. Vinetz explains that a good example of herd immunity is the measles. -- "The idea is that if we have herd immunity, it means that we reduce the transmission of a disease within a population," Vinetz says. "The best example to think about is measles. If 95% of everyone is vaccinated -- -- transmission. While "active immunity," or immunity a person builds in response to actually contracting a disease, is most effective and long-lasting, experts beg people not to intentionally infect themselves with -- -- actually contracting a disease, is most effective and long-lasting, experts beg people not to intentionally infect themselves with SARS-CoV-2 in an attempt to build immunity. Fighting coronavirus: COVID-19 tests, vaccine research, masks, ventilators -- -- Vial of remdesivir +30 More How vaccines promote herd immunity The purpose of vaccines, Orient says, is "to expose people to something -- -- The purpose of vaccines, Orient says, is "to expose people to something that induces immunity without making them very sick," explaining that vaccines are either tiny doses of a pathogen, a dead microorganism or one that is similar but weaker. -- -- one that is similar but weaker. "You need upwards of 70% of protective immunity in a population to prevent large scale propagation," Vinetz explains, and that often requires immunization, particularly in regard to diseases that have -- -- gettyimages-961181800 gettyimages-961181800 Vaccines have been successful in creating herd immunity to several infectious diseases. Getty Images -- -- favorable," she says. "For milder diseases, not necessarily so." Vaccines can have adverse effects for some people, too, and immunity wanes over time, so the importance of vaccination depends on a number of factors, including severity and prevalence of the disease, vaccine -- -- control), or cure of the sick before disease can be transmitted." Why we need herd immunity -- If there is no herd immunity, people will continue to contract and spread diseases, and, unfortunately, people will continue to die from -- spread diseases, and, unfortunately, people will continue to die from these diseases. The CDC defines herd immunity, or community immunity, as "a situation in which a sufficient proportion of a population is immune to an infectious disease (through vaccination and/or prior -- -- "Even individuals not vaccinated (such as newborns and those with chronic illnesses)," the CDC continues in its definition of herd immunity, "are offered some protection because the disease has little opportunity to spread within 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 has immunity, naturally or by vaccination. Because no one has immunity, and the virus is contagious, it spreads quickly and easily. -- -- contagious, it spreads quickly and easily. What will it take to have coronavirus herd immunity? -- There are two ways to produce herd immunity against a disease: develop and administer a safe and effective vaccination, or wait for the disease to make it around through a population. -- -- vaccine to be developed. Vinetz figures that the US is nowhere near the point of herd immunity to the novel coronavirus: "If we have 330 million people in the States and 1% are infected, that's 3.3 million people and that still means -- -- If you take Vinetz's estimation that at least 70% of a population must be immune to a disease to produce herd immunity, that means at least 231 million people in the US must contract and recover from the disease. -- -- the US on the CDC website, which is updated continuously). "It doesn't require Einstein to figure out that we are nowhere close to herd immunity," Vinetz says starkly. However, too many important factors remain unknown to simply allow the -- -- gettyimages-1206443505 +55 More When will we have coronavirus herd immunity? -- We've also now seen that striving for herd immunity doesn't work in practice: Sweden, one country that many people looked to as an example because of its leniency during the pandemic, is telling other countries -- -- not to follow in its footsteps because the death toll is "unnerving." Whether we will see herd immunity to SARS-CoV-2 in the future depends heavily on a number of factors -- particularly, Orient says, "whether we allow people to move around." -- -- unless and until there is an effective vaccine," she explains. "For some diseases, like the common cold (coronaviruses are one cause) there isn't much herd immunity because the virus changes or the vaccine just doesn't work, like malaria." -- -- doesn't work, like malaria." When asked about localized herd immunity, or herd immunity within specific regions with high numbers of coronavirus cases (such as New York and California), Vinetz says the concept doesn't really matter if -- -- "We're such a mobile society," he says, so if stay-at-home orders are relaxed or removed, "if people start getting on buses and planes and trains and visiting other areas," localized herd immunity means nothing. -- -- Close Discuss: Can herd immunity help stop coronavirus? What we know now (BUTTON) Sign in to comment