Search Results for coronavirus

Misinterpreted New York Times report leads to false claim that the number of COVID-19 cases in the U.S. is inflated by up to 90%

It is important to distinguish between a person who is infected and a person who is contagious. PCR tests with a high level of sensitivity can produce a positive result even though a person only harbors trace amounts of virus or even dead virus. Hence a positive test result without information about viral load is not of practical value in determining if an infected person should self-isolate and whether their contacts should be traced. However, while a positive test may not tell us whether the person is contagious, it can tell us whether the person is infected. It is therefore appropriate to count positive PCR tests as COVID-19 cases.

Adequate immunization and improved sanitation together protect against infection from both wild and vaccine-derived poliovirus

The oral polio vaccine contains a live but weakened form of the poliovirus, which does not cause infection. In areas with poor sanitization, however, the virus shed by vaccinated children can remain in the environment for long periods of time, and on rare occasions, regain its ability to cause disease. Since immunization protects against both the wild poliovirus and vaccine-derived polioviruses, full vaccination of 80-85% of the children can confer herd immunity and stop polio transmission. And improved sanitation can prevent the emergence of infectious vaccine-derived poliovirus strains.

COVID-19 test kits were not purchased in 2017 and 2018; claim is based on mislabeled data

Test kits for the virus that causes COVID-19 were only developed in 2020, since scientists only discovered the virus in January 2020. It is impossible for scientists to develop a test kit for a virus that is undiscovered. The claim that COVID-19 test kits were being sold in 2017 and 2018 is based on an error in data labeling on the World Integrated Trade Solutions (WITS) website, a resource that allows users to access and retrieve information on trade and tariffs. The error has since been corrected.

Masks offer only partial protection from the virus that causes COVID-19, but their effectiveness can be enhanced with other measures like physical distancing

It is an oversimplification to claim that “either masks work or they don’t”, because the underlying assumption is that face masks must work perfectly, and if they do not, then they don’t work at all. On the contrary, the risks of disease exposure and the degree of protection one can achieve from different safety measures lie on a continuum. Even though face masks do not confer 100% protection to the wearer or to others, scientific evidence has demonstrated that face masks reduce the transmission of viral respiratory infections like COVID-19 to some degree. Therefore, it remains important for people to continue to practice physical distancing and proper hand hygiene as the combination of the three measures greatly enhances the effectiveness of any one measure used alone.

False claim shared by President Trump that only 6% of CDC-reported deaths are from COVID-19 is based on flawed reasoning

Cause of death is defined as a medical condition that triggers a chain of clinical events that leads to the death of a patient. In contrast, comorbidities are medical conditions, either pre-existing or resulting from the primary medical condition, that weaken a patient’s resistance to injuries or diseases and indirectly contribute to their death. Many patients who died from COVID-19 had comorbidities, suggesting that these conditions increased their likelihood of death from COVID-19. For these patients, COVID-19 remains their cause of death, as many would not have died from their comorbidities.

Human DNA does not produce a positive result on the RT-PCR test for SARS-CoV-2

The reverse-transcription PCR (RT-PCR) test is the method of choice for detecting SARS-CoV-2 in samples and is highly specific for the virus. For a PCR test to successfully amplify nucleic acids (DNA or RNA) in a sample, it is necessary for a pair of primers, which are short sequences of single-stranded nucleic acids that recognize and bind to a specific region of the genome, to flank the same target sequence. If only one primer in the pair is able to do so, amplification does not take place and the test produces a negative result. Therefore, even when an RT-PCR test for SARS-CoV-2 uses a primer that matches a human gene sequence, the test would not produce a positive result with human DNA alone because the other primer does not match the human gene sequence.

A vaccine against SARS-CoV-2 would be useful even if the survival rate from COVID-19 is high

Due to the high transmissibility of SARS-CoV-2, hundreds of thousands of people have died despite the high survival rate of COVID-19. A vaccine would limit transmissibility and thereby reduce the total number of deaths. Furthermore, by reducing the rate of infection or perhaps simply disease severity, a vaccine could also reduce non-lethal yet potentially permanent conditions, such as damage to the heart, lungs, and other tissues. Finally, a vaccine could slow the propagation of the virus through a population by helping to achieve herd immunity, which protects vulnerable persons such as the elderly and immunocompromised. Vaccines confer a range of important benefits, even for diseases with a high average rate of survival.

People infected with SARS-CoV-2 can transmit the virus to others, even if they do not show symptoms of the disease and are not considered sick

Scientific evidence indicates that about half of SARS-CoV-2 transmission occurs before infected individuals experience any symptoms of COVID-19. Studies show that asymptomatic carriers, who are people that never develop symptoms of COVID-19, carry as much of the SARS-CoV-2 virus as symptomatic patients and can spread the virus if they do not take adequate measures, such as wearing masks or maintaining physical distance from others.

Listicle of “facts” about COVID-19 contains numerous inaccurate and misleading claims

In 2020, more deaths have occurred than expected relative to previous years (i.e., excess deaths), even more than the number of excess deaths that occurred during the particularly severe flu season of 2017-2018. Countries like Sweden and Japan that did not implement lockdowns have managed to control the outbreak of COVID-19, but this may be due to unique cultural factors such as the voluntary practice of physical distancing and mask-wearing. Published studies have shown that these measures are effective at significantly reducing virus transmission.

Current COVID-19 mortality rate does not predict the future probability of dying from the disease

The COVID-19 cause-specific mortality rate is the proportion of people who have died from the disease relative to the entire population. It is sometimes used to compare mortality between populations of different sizes. It also represents the likelihood that a randomly selected person in the population who was alive at the start of the pandemic already died of the disease. However, it cannot be used to predict an individual’s likelihood of dying from COVID-19 in the future, given the dynamic nature of the epidemic and that every individual’s risk of contracting and dying from COVID-19 is different.