Centers for Disease Control and Prevention Changed guidelines for wearing masks On May 13, 2021, many Americans remained a little confused. This allows anyone who is fully vaccinated to participate in indoor and outdoor activities, large or small, without having to wear a mask or physically separate.
Anthony Fauci, President Biden’s Chief Medical Advisor, said the new guidelines are “Based on the evolution of scienceAnd “act as an incentive” Almost two-thirds of Americans If you haven’t been fully vaccinated yet, go ahead and shoot.
But some people Vaccination is not possible Because of the underlying conditions. Others whose immunity is weakened by cancer or treatment, May not be fully protected By their vaccination.. For children aged 12 to 15 years May 10, 2021 only for Pfizer-BioNTech vaccine.And COVID-19 vaccine has not yet been approved Almost 50 million children Under 12 years old in the United States.
Some are worried when the restrictions are lifted and people start to leave their masks at home. Is it possible to catch COVID-19 from a vaccinated person?
Vaccines do not always prevent infection
Researchers wanted Designing a Safe COVID-19 Vaccine that is Prevent at least half Percentage of people vaccinated against COVID-19 symptoms.
Fortunately, for vaccines very Outperform Expectations. For example 6.5 million inhabitants of IsraelThe Pfizer-BioNTech mRNA COVID-19 vaccine was found to be 95.3% effective after both injections, over 16 years of age. Within two months, of the 4.7 million people who were fully vaccinated, the number of detectable infections was reduced by a factor of 30.Similarly California And TexasOnly 0.05% of fully vaccinated health care workers were COVID-19 positive.
Vaccine developers have said that in addition to preventing the disease, their vaccine is “Sterilized immunity, ”Vaccination prevents bacteria from even entering the body. This bactericidal immunity means that the vaccinated person does not catch the virus or further infect it. However, in order for the vaccine to be effective, it is ineffective. Bacteria need to be prevented from infecting vaccinated people.
The· Soak inactivated polio vaccine, For example Does not stop completely Poliovirus propagates in the human intestine.But that is Very effective It helps prevent catastrophic illness by inducing antibodies that prevent the virus from infecting the brain and spinal cord.good Vaccines provide effective and durable training Due to the body’s immune system, it is ready to initiate an optimal response when it actually encounters a pathogen that causes the disease.
Regarding COVID-19, immunologists still say they “Correlation of protection, “A factor that predicts how well someone is protected from the coronavirus. Optimal amount of”Neutralizing antibody, ”The type that not only binds to the virus but also prevents the virus from infecting is enough to dodge Repeated infection..Scientists are still evaluating Immune endurance What the COVID-19 vaccine offers Where on the body It’s working.
Can vaccinated people spread the coronavirus?
Immunologists also hope that vaccines that protect against viral diseases will reduce the transmission of the virus after vaccination. However, it is actually difficult to know for sure whether vaccinated people are not spreading the bacterium.
COVID-19 raises specific challenges as people with asymptomatic and presymptomatic infections can spread the disease. Inadequate contact tracing and testing means a person who is asymptomatic. Rarely detected..Some scientists estimate the number of asymptomatic COVID-19 infections in the entire population Can be 3 to 20 times higher Than the confirmed number of cases.Studies have shown that undocumented cases of COVID-19 in people who have experienced asymptomatic or very mild illness may be the cause. Up to 86% of all infections, Other studies Inconsistent with high estimate..
To One studyThe CDC tested volunteer health care workers and other front-line workers at eight locations in the United States for SARS-CoV-2 infection for three months each week, regardless of symptoms or vaccination status. Researchers found that fully vaccinated participants were 25 times more likely to test positive for COVID-19 than unvaccinated participants. ..Such findings are that if vaccinated people are well protected from infection, they Also, it is unlikely to spread Virus. However, without contact tracing to track infections in larger populations, it is impossible to know if the assumptions are correct.
What we do know is that if someone gets sick with COVID-19 after vaccination, it is a so-called “breakthrough infection”. Symptoms will be mild..Studies show that people who test positive for COVID-19 Only their first vaccine dose Had Low virus level in the body Than unvaccinated people who tested positive.Researchers believe that the reduced viral load suggests that people infected with the virus have been vaccinated. Less infectious There are far fewer viruses that can spread to others.
Preprint studies that have not yet been peer-reviewed suggest that the Moderna mRNA COVID-19 vaccine may create a fight against the coronavirus. Antibodies in the oral cavity and nasal fluid..Since then That’s where SARS-CoV-2 comes in.Antibodies in the mouth and nose should prevent the virus from entering the body and effectively provide “bactericidal immunity”. This also means that vaccinated people will probably not spread the virus through respiratory droplets.
These evidences are promising.But without further research, scientists I can’t come to a conclusion yet The COVID-19 vaccine actually prevents all infections. Research being tried Answering this question directly through contact tracing is still in its infancy. Researchers track COVID-19 infections between vaccinated and unvaccinated volunteers, and their close contacts.
Protection and prevention are inextricably linked
Vaccines help slow the spread of infections by breaking the chain of infections. Fewer and less unprotected people will eventually be infected with the virus.This is how to increase the vaccine Herd immunity – Sensitive and unvaccinated people are surrounded by a “flock” of people who have acquired immunity due to vaccination or previous infection.However, research is biological and biological and Social reasons, It’s unlikely that vaccination alone Achieves herd immunity against COVID-19 and completely contains coronavirus.
In fact, vaccination It may take a long time alone To eradicate all illnesses.Even almost “eliminate” illnesses such as chickenpox, measles and whooping cough Can resurface Immunity is weakened and vaccination rate is reduced.
Recent outbreaks of infectious diseases Vaccinated New York Yankees It shows that vaccinated people can not only be infected yet, but can also be infected with the coronavirus and close contact. Highly tested groups, such as professional sports teams, are due to the fact that mild asymptomatic infections may be more frequent than actually reported among vaccinated people in the general population. I’m shining a spotlight.A similar Outbreak of airport workers in Singapore Shows that new and more infectious mutants can spread rapidly, even among those who are fully vaccinated.
The CDC’s relaxed guidelines for masking are intended to reassure vaccinated people that they are safe from serious illness. And they are. But for unvaccinated people who interact with them, the situation is less clear. With me until herd immunity to COVID-19 was achieved and clear evidence accumulated that vaccinated people would not spread the virus. Many epidemiologists We believe it is better to avoid situations that can lead to infection.In combination with vaccination Continuous masking And social distance is still an effective way to stay safe.
Sanjay Mishra, Project Coordinator & Staff Scientist, Vanderbilt University Medical Center, Vanderbilt University
This article will be republished from conversation Under a Creative Commons license.
