Facts have proved that the COVID vaccine has achieved great success Reduce the number of cases, hospitalizations and deathsHowever, there is always uncertainty as to whether vaccinated people who are still infected—may have very mild symptoms or no symptoms at all—may transmit the virus to others. Such silent transmission may complicate efforts to control the pandemic.
In recent months, data on the risk of transmission after vaccination has sprung up. These findings have important implications for how quickly we can control the pandemic and what we say to those who are hesitant to vaccinate.
Vaccine trials usually aim to determine whether immunization can prevent people from getting sick.These are the power figures in the headlines – up to 95% Reduce symptomatic COVID cases with two FDA-authorized mRNA-based vaccines. But these trials provide little data on whether the vaccine can completely prevent infection, and this is the most reliable way to minimize the spread of the virus.
considering At least one third COVID infection has no symptoms at all, but it is still potentially contagious, so it is very important to know whether the vaccinated person may become a carrier of the virus. However, not every carrier will transmit the virus. If the carrier’s viral load is relatively low-which means fewer virus particles are shed when breathing and speaking-the risk of transmission will be greatly reduced. Therefore, a possible indirect benefit of the COVID vaccine may be to reduce the viral load of so-called breakthrough cases or vaccinated infected persons.
Since many health care workers are now regularly tested for COVID, whether they have symptoms or not, most of the early real-world data on the effectiveness of vaccines in blocking infection comes from this population.In several studies of fully vaccinated health care workers – those more than two weeks after the second dose of the mRNA-based vaccine – the likelihood of symptomatic or asymptomatic infection was reduced 80% to 90%, Compared with those who have not been vaccinated.
There is also good news regarding the viral load of breakthrough cases.Israeli researchers Have learned The infected person was vaccinated. The viral load of these breakthrough cases is about three to four times lower than that of unvaccinated infected people.British researchers Report Similar results. They also found that infected people who were vaccinated tested positive for about a week less than people who were not vaccinated.
We now also have evidence that, based on contact tracing studies, infected people with lower viral loads spread the virus to fewer people. US, India and Spain. This is supported by the laboratory Research Prove that nasal samples from an infected person with a lower viral load are less likely to contain infectious virus.
The delta change of the coronavirus is reflected in the dominant position in the United States and many other countries, and may lead to an increase in viral load 1,000 times higher It is higher than the level normally associated with the ancestral lineage of viruses at the beginning of 2020. This higher viral load makes Delta infections more contagious, which leads to more breakthrough cases, although many are mild or asymptomatic. But mRNA-based vaccines still provide strong protection, with effectiveness between 80% and 90% against symptomatic infections. The ability of these vaccines to drastically reduce viral load in breakthrough cases may be a valuable tool to contain the spread of Delta variants.
The sum of these impressive data should strengthen people’s confidence that the COVID vaccine is very effective in reducing the spread of the virus. This shows that vaccinating the majority of Americans across the country is our most reliable bet to return to normal life. Completely eliminating the spread of the virus may be an unattainable goal, but mass vaccination in the United States and around the world will make COVID the background of our lives.
So far, based on available data from vaccine trials, most of the public health information surrounding vaccination has focused on personal interests. The efficacy of the COVID vaccine in preventing diseases is indeed remarkable. But as more and more evidence proves that reducing transmission is effective, it’s time to start emphasizing social benefits—and the personal responsibility to avoid harm to others.
Especially because so many COVID cases are asymptomatic, people who have not been vaccinated may become carriers of the virus unknowingly. In fact, those who are at the lowest risk of becoming severely ill or dying due to COVID-young and healthy people-are most likely to become these unknowing carriers because they lead the most active lives and are in constant contact with many other people.
For those who are hesitant about vaccination, the most important question is not “What does the vaccine do for you?” It is, “If you don’t get the vaccine, how many people will you harm?”
At the beginning of the pandemic, in February 2020, an international business meeting In Boston, about 175 attendees became a super spread event. It is estimated that as of November 1, 2020, Over 300,000 That meeting alone triggered an infection in the United States.
We are all connected in a huge, invisible network. For the amazing density of many of our interconnections, the “six degrees of separation” is not an exaggeration. If you refuse to be vaccinated and contract the coronavirus, the number of people you may have accidentally harmed could be astronomical.
Mitigation measures such as testing, alienation, and masking are imperfect tools to prevent the spread of viruses. In this pandemic, vaccination is our closest thing to certainty. Data already exists, and vaccines are very effective in reducing transmission.
The message for those who have not yet been vaccinated should be: Don’t let the virus use you to harm others.
This is an opinion and analysis article; opinions expressed Author or author Not necessarily those Scientific american.