Editor’s note: Therefore, you have received the coronavirus vaccine. After waiting for two weeks, your immune system can react to the vaccine. Now you have received a full vaccination. Does this mean that you can travel through the world as you did in the past without worrying about spreading this virus? Deborah Fuller is a microbiologist at the University of Washington, researching coronavirus vaccines. She explained how science shows post-vaccination spread-and whether new variants can change this equation.
1. Can vaccination completely prevent infection?
The shortest answer is no. After vaccination, you can still be infected. However, your chance of getting serious illness is almost zero.
Many people believe that the vaccine acts as a shield and can completely prevent the virus from infecting cells. But in most cases, the vaccinated person can prevent disease, not necessarily infection.
Everyone’s immune system is slightly different, so when the vaccine is 95% effective, it means that 95% of people who receive the vaccine will not get sick. These people may be completely protected from infection, or they may be infected but have no symptoms because their immune system can quickly eliminate the virus. The remaining 5% of vaccinators may become infected and get sick, but it is extremely unlikely that they will be hospitalized.
Vaccination does not prevent you from being infected 1
2. Does infection always mean spread?
Transmission occurs when enough virus particles from an infected person enter the body of an uninfected person. In theory, anyone who is infected by the coronavirus can spread it. But the vaccine will reduce the occurrence of this situation.
Generally, if vaccination does not completely prevent infection, it will greatly reduce the amount of virus flowing from your nose and mouth (this process is called “shedding”) and shorten the time it takes for the virus to clear. this is a big problem. People who distribute less virus are less likely to spread it to others.
This seems to be the case with the coronavirus vaccine. In a preprint study that has not yet been peer-reviewed, Israeli researchers tested 2,897 vaccinated people for signs of coronavirus infection. Most people do not have a detectable virus, but the amount of virus in an infected person is a quarter of the similar time after infection in an unvaccinated person.
Fewer coronavirus means less chance of spreading it, and if the amount of virus in your body is low enough, the chance of spreading it may be almost zero. However, researchers do not yet know where the cut-off point of the coronavirus is, and because the vaccine does not provide 100% protection against infection, the Centers for Disease Control and Prevention recommends that people continue to wear masks and keep social distance even if they are vaccinated. The vaccine.
3. How about the new coronavirus variants?
New variants of the coronavirus have emerged in recent months, and recent studies have shown that vaccines are less effective for certain vaccines, such as the B1351 variant first discovered in South Africa.
Every time SARS-CoV-2 replicates, it gets a new mutation. In recent months, researchers have discovered new variants that are more infectious, which means that a person needs to inhale less virus to be infected; while other variants are more transmissible, which means they increase The number of viruses circulated by a person. Researchers have also discovered at least one new variant, which appears to be better at evading the immune system based on early data.
So what does this have to do with vaccines and transmission?
For the South African variant, the vaccine can still provide more than 85% protection against severe COVID-19 infection. However, when you count mild and moderate cases, they can only provide about 50%-60% protection at best. This means that at least 40% of vaccinators will still be infected with a strong enough virus and carry enough virus in their body to cause at least a moderate degree of disease.
If the vaccinated person has more viruses in his body and less virus is needed to infect another person, then the vaccinated person is more likely to transmit these new coronavirus strains.
If all goes well, the vaccine will soon reduce the rate of serious diseases and deaths worldwide. To be sure, any vaccine that reduces the severity of the disease will also reduce the overall number of viruses circulated at the population level. However, due to the emergence of new variants, it is still possible for vaccinated people to shed the coronavirus and spread it to others, regardless of whether they have been vaccinated. This means that it may take longer for vaccines to reduce transmission and immunize the population compared to these new variants that have never appeared. To be precise, how long will it take to strike a balance between how effective the vaccine is against emerging strains and the transmissibility and infectivity of these new strains.
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This article is republished from The Conversation under a Creative Commons license. Read the original article here: https://theconversation.com/can-vaccinated-people-still-spread-the-coronavirus-155095.