The endless news cycle and viral social media warn that people who have been vaccinated against COVID-19 will have a “breakthrough infection.” These reports give the false impression that the protection provided by the vaccine is not working-they may exacerbate the silence of the millions of people in the United States who have not been vaccinated. However, it is known that such infections do not only occur after COVID vaccination. They often occur after being vaccinated with influenza, measles and many other diseases.
SARS-CoV-2 is the virus that causes COVID, but it is special in one respect: it provides courses in immunology for the general public more than any other pathogen—and other factors such as “breakthrough infection” and “herd immunity”. The term “class” has gained wide familiarity. Kawsar Talaat, an associate professor in the Department of International Health at the Bloomberg School of Public Health at Johns Hopkins University, said: “It almost feels like not only a microscope, but also an electron microscope. You can observe every occurrence of the COVID vaccine. one thing. She pointed out that no vaccine is 100% effective. “Although some vaccines are better than others, most of them have some breakthrough infections. “
“Breakthrough” only means people who are vaccinated Pathogen tested positiveIt’s not that they will get sick or spread the infection to other people. Most infected vaccinated people have no symptoms, and those with symptoms tend to be milder.Even with the Delta variant of SARS-CoV-2, the vaccine Shows good protection against symptomatic diseases and deaths.
Nationwide, as of August 2, the Centers for Disease Control and Prevention reported that more than 164 million people have been fully vaccinated, Less than half of the total population.However 97% of people hospitalized with COVID-19 are not vaccinated.
These figures emphasize how reality is sometimes distorted in public consciousness. “Interestingly, through conversations with my friends and family and on social media, I think people are more concerned about these breakthrough infections than their prevalence,” said Tara Smith, professor of epidemiology at the School of Public Health. Kent State University.
Another concern of breakthrough cases is the transmission of the virus to others. But infected people “are often unlikely to spread, no matter what we are looking at,” Smith said. “We have seen this in viruses and bacteria-even with whooping cough, this is one of the reasons why people try to “cocoon” around babies. The baby cannot be vaccinated against the disease at first. People who spend time together are vaccinated as a protective barrier because they were not vaccinated against whooping cough before they were two months old.
The COVID vaccine is Expected to reduce spread Nick Grassley, a professor in the Department of Epidemiology of Infectious Diseases at Imperial College London, said that among those with asymptomatic breakthrough infections. He added: “Therefore, you have been vaccinated and are unlikely to be infected. Even if you are infected, the risk of spreading the virus will be reduced.” One of the reasons is the number of coronaviruses, that is, the viral load. The number of infections is low, so the number of transmissions is small. The appearance of this model in the Delta variant is unclear.A study published by the U.S. Centers for Disease Control and Prevention in late July pointed out that Virus counts in vaccinated and unvaccinated people are similarHowever, in this study, the researchers did not perform tests to confirm the true viral load or report transmission data from vaccinated people, and the “unvaccinated” group included some vaccinated people.
Because the vaccine is ineffective, there will be no breakthrough cases. Immunity will weaken over time, and the effectiveness of vaccines against specific pathogens may be reduced. Talaat said the measles-mumps-rubella (MMR) vaccine is an example: it is very protective against measles, but it is not as strong against mumps.
Even the powerful measles vaccine has a history of breakthrough infections. A measles outbreak in the late 1980s mainly involved young people who were vaccinated, leading to policy changes, calling for Two doses instead of oneTalaat said that the first dose of MMR can provide about 90% of lifetime protection, but the second dose can cover about half of the remaining 10%. Given the highly contagious nature of measles, obtaining the highest possible coverage is essential.
Influenza vaccine is the most relevant vaccination for breakthrough infections. Smith said that if such cases of influenza were tracked as closely as breakthrough SARS-CoV-2 infections, then the former “would be more” because “we know that influenza vaccines are not that effective.” She said, similar to cases that occur with other vaccines. In contrast, the breakthrough COVID case is “just another Wednesday”.
The COVID vaccine seems to be better than the usual flu vaccine. So far, these shots have neutralized the COVID variant very effectively. Grassly said that, in fact, COVID has not overcome immunity like the flu virus. Certain types of flu are better at avoiding human ingenuity, Vaccines in some flu seasons are very ineffective And a large number of breakthrough cases.
Talaat pointed out that with regard to influenza, “we don’t call it a “breakthrough”, but say “47% effective this year” or “60%…” We are talking about curative effects.” But she said that despite the effectiveness of the flu vaccine Relatively poor, but they are “better than nothing”, can save lives and prevent hospitalization.
If the vaccinated population is small and the number of cases in the community is high, the breakthrough rate may increase. On the contrary, the high vaccination rate means that the vaccinated population accounts for a larger proportion of the total cases.If almost everyone is vaccinated, then any case that occurs is More likely to happen to people who have been vaccinatedThis is the case of the Massachusetts outbreak, where 74% of the people who tested positive in the area were vaccinated, and approximately 69% of eligible residents in the area were vaccinated.
Other factors contribute to the excessive number of vaccinated patients with breakthrough infections, including age and health conditions associated with a weakened immune system. Normally, these patients’ immunity levels will respond sluggishly to vaccines, so they may be at a higher risk than young unaffected people who have not been vaccinated.
Similar to the routine injections used for whooping cough, people with suppressed immune systems or weakened immunity may need to boost COVID injections.Talat pointed out Good response to third dose of COVID vaccine In patients receiving organ transplants. France and Israel have already added a recommended third dose to some recipients with weakened immune systems, and the United Kingdom is considering doing so. The CDC Immunization Practice Advisory Committee held a meeting on July 22 to review data related to intensified injections for people with weakened immune systems and concluded that The third dose may be for this patient group.
In the earnings call at the end of July, Pfizer cited unpublished preliminary results 23 clinical trial participants After the third dose of mRNA vaccine, this shows that the protection of the Delta variant is enhanced.exist Ready comments On the earnings call, the company said that it expects to submit the results of the third dose to the FDA in August to obtain an emergency use authorization for a booster.
At the same time, “We don’t know if the booster will work, but if we vaccinate everyone, then this will protect 2.7% of people in the country are immunocompromised,” Talat said. “And they don’t have to worry about how good or bad their immune system is in fighting the virus. “