the science ,” Kennedy said . But not all infectious disease experts agree on this . Without speaking specifically about St . Luke ’ s policy , Dr . John Zurlo , chief of infectious disease at Thomas Jefferson University Hospital , said there is no reason for anyone to defer getting vaccinated , even if they have natural immunity . “ Given the unpredictability of COVID in general and delta in particular , our best defense is universal vaccination , the sooner the better ,” Zurlo said .”
Many individuals are fighting for their choice to rely on community protection ( herd immunity ) – or what experts are preferring to call natural immunity – maintaining that for individuals not in high-risk groups and / or with co-morbidities , COVID-19 illness is mild and resolves in a short amount of time . Developing natural antibodies , they say , confers protection and certain benefits that vaccines do not . A recent pre-print study by researchers at Rockefeller University found that natural infection can create B cells , a type of white blood cell that produces more potent antibodies for fighting COVID-19 and its variants than the B cells created after vaccination .
Greiss ( 2021 ) quotes Dr . Michael Nussenzweig , one of the study ’ s authors and head of Rockefeller ’ s Laboratory of Molecular Immunology , as noting that , “ In this instance benefits don ’ t outweigh risks . Natural infection is much more likely to result in serious sickness or death , whereas a vaccine protects against serious illness or death from COVID-19 infection .”
Another recent study from Israel posted on pre-print server medRxiv showed natural immunity provided longer-lasting , stronger protection against infection , symptomatic disease and hospitalization due to the delta variant than the Pfizer vaccine . However , the study has multiple limitations . Researchers said the results are only applicable to the Delta strain and only the effectiveness of the Pfizer vaccine was examined . The researchers also said they may have underestimated asymptomatic infections and the results may be confounded by certain factors like health behaviors and chronic illness among vaccinated subjects .
Natural immunity is not without its complications , public health experts insist , pointing to a study released by the Centers for Disease Control and Prevention ( CDC ) in August that found subjects who had natural immunity but were unvaccinated were more than twice as likely to be reinfected with COVID-19 as those who had natural immunity and those who got their shots .
Greiss ( 2021 ) quotes Ed Easterly , with the law firm Hoffman , Hlavac & Easterly , as stating that it is legal for employers who have vaccine mandates in place to allow deferrals for employees with natural immunity : “’ There are no laws governing this kind of exemption like there are for medical or religious exemptions ,’ he said . Because of this , employers that are considering deferrals for the naturally immune are trying to figure out how to structure that as an internal policy . He said there are considerations for employers such as how they will establish whether somebody had COVID-19 as well as determining how long they will allow employees to defer their shots . ‘ Every employer can handle it in a different way because there ’ s no set standard for that type of exemption ,’ Easterly said . ‘ It ’ s not the same as the medical or religious ones where there are laws in place that deal with that .’ There are limitations , though . For example , the EEOC has stated that , unlike vaccinations , employers cannot mandate antibody tests because they are not reliable . Easterly said most employers aren ’ t allowing employees to defer vaccination because of natural immunity but the situation is developing and that could change .”
UNC ’ s David Weber says natural immunity is “ not acceptable ” as a replacement for vaccination . “ For people who have had natural disease , we don ’ t know how long that immunity lasts ; with the vaccine , they get a nice boost of immunity . Immunizing is permitted both under the EUA and FDA approval and is explicitly recommended by the CDC . ‘ Natural infection ’ should not be an excuse for not getting the vaccine . Similarly , we don ’ t know what the level of antibodies are that are protective . No antibodies are very bad , and you ’ re certainly not protected . A lot of antibodies are good , but we still can ’ t guarantee you won ’ t get disease . And in between we can ’ t say anything . That is not true for other diseases . An example is hepatitis B . We know the protective level of antibody there . We also know that if someone has antibodies against measles , mumps or rubella , that they won ’ t become ill when you get exposed , and we do allow people to bring in an antibody level and not get a vaccine or prove to us that they don ’ t need a hepatitis B vaccine . But we don ’ t have sufficient data to do that for COVID ; we simply don ’ t have that data .”
Weber says he prefers the term “ community protection ” to “ herd immunity ,” “ meaning everyone around you is immune . But you ’ re not immune , you ’ re what we call ‘ cocooned ,’ you ’ re protected by everyone around you and not everyone is immune , as a very small percentage of our population is actually susceptible to measles , either because they refused the vaccine , or they couldn ’ t get it because of a contraindication . But we don ’ t have circulating measles because so many people are immune that it just can ’ t maintain itself in the population . We had hoped , just based on how infectious the original strains of COVID were , that between vaccine and natural disease , we would reach a level of immunity . The predicted level was in the order of 70 percent to 80 percent that we would see the number of cases dramatically decrease and potentially , not eliminate it , but get down to very , very low levels . But the Delta variant threw that out the window , for two reasons . One , Delta is much more infectious and two , we now know about breakthrough disease , that people fully immunized can become ill . They rarely become very sick , but they can become ill and transmit disease .”
Weber continues , “ At this point I don ’ t know that it ’ s mathematically possible to reach community protection levels . I saw the data from a study of blood donors that 80 percent of the U . S . population has either natural disease or has been vaccinated , yet we ’ re in the middle of a surge because of Delta . Maybe if everybody gets vaccinated , particularly if we develop boosters that work even better , we can reach natural immunity . To me , COVID is now endemic . It ’ s not going to disappear the way SARS 1 disappeared ; it will be endemic just like the H1N1 influenza from the 2009 pandemic is now endemic . We now have four endemic coronaviruses . What ’ s not clear is , between vaccines and wearing masks and other things we can do , can we get back to normal and how this will affect morbidity and mortality .”
He says there are bright spots on the horizon . “ A few weeks ago , monoclonal antibodies were FDA-authorized for post-exposure prophylaxis . New drugs are in development that will be effective for treatment . So , we have a variety of other strategies that will help mitigate the effects of COVID in the future , along with vaccines , of course . We need to learn to live with COVID and know how to deal with it in the long run . The way to do it is a combination of vaccines , better treatments that mitigate its effects , and maybe utilizing some of the interventions that