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What are the variants of Covid, how can you stay safe as they spread? A doctor answers | Health

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With the delta variant accounting for more than 93% of Covid-19 cases in the United States at the end of July 2021, questions are raised about how to stay protected against the evolving forms of the SARS-CoV-2 virus.

Here, pediatrician and infectious disease specialist Dr Lilly Cheng Immergluck of the Morehouse School of Medicine answers some common questions about the variants and what you can do to best protect yourself.

1. What are variants and how do they emerge?

Viruses mutate over time to adapt to their environment and improve their survival. During the pandemic, SARS-CoV-2, the novel coronavirus that causes COVID-19, mutated enough to alter both its ability to spread among the population and its ability to infect people.

These new strains are called variants. The United States Centers for Disease Control and Prevention currently classifies variants into three categories, ranked from least to most concerning:

Variant of interest (VOI): Has characteristics that may reduce the ability of your immune system to prevent infections. For example, you may have heard of VOI eta, iota, or kappa.

Variant of Concern (VOC): Are less sensitive to treatments or vaccines and are more likely to escape diagnostic detection. They tend to be more transmissible or contagious and lead to more serious infections. Alpha and delta are VOCs, for example.

High Consequence Variant (VOHC): are significantly less responsive to existing diagnostic, prevention and treatment options. They also lead to more serious infections and hospitalizations. No VOHC has been identified so far.

The World Health Organization uses similar classifications, but their definitions may differ from those of the CDC in the United States, as the characteristics and effects of variants may differ depending on geographic location.

2. Are variants always more harmful?

A variant can be more or less dangerous than other strains depending on the mutations in its genetic code. Mutations can affect attributes such as a viral variant’s contagiousness, how it interacts with the immune system, or the severity of symptoms it triggers.

For example, the alpha variant is more transmissible than the original form of SARS-CoV-2. Studies show that it is between 43% and 90% more contagious than the virus that was most common at the start of the pandemic. Alpha is also more likely to cause serious illness, as indicated by increased rates of hospitalization and death after infection.

Even more extreme, the delta variant is said to be almost twice as contagious as previous strains and could cause even more serious illness in those who are not vaccinated.

The viral load of people infected with delta – that is, the amount of virus detected in the nasal passages of an infected person – is also said to be more than 1,000 times that of people infected with the original form of the virus. SARS-CoV-2. Recent evidence also suggests that unvaccinated and vaccinated people carry similar viral loads, which further contributes to the particularly contagious nature of this variant.

3. Which variations are the most common?

Within months, the delta variant became the predominant strain in the United States, accounting for the vast majority of COVID-19 cases at the end of July 2021.

But there are regional variations across the country. As of July 31, the CDC estimated that the alpha variant accounted for more than 3% of identified cases in an eight-state region including Georgia, Florida, and Tennessee, compared with less than 1% in the region including Iowa, Kansas. , Missouri and Nebraska. The CDC tracks variants in cooperation with state health departments and other public health agencies. Samples of COVID-19 infection from across the country are genetically sequenced weekly to identify existing and new variants.

And new variants will likely continue to appear as the virus evolves. Delta plus, for example, is a subline of delta. The effects of this sub-variant remain to be determined.

4. How do vaccines resist variants?

Researchers are working to determine how effective the three COVID-19 vaccines currently authorized for emergency use in the United States are in preventing infection with variants under “real-world” conditions where distribution and frequency of variants constantly change. Several preliminary studies that have not yet been peer reviewed suggest that these vaccines are still effective in preventing serious infections and deaths from COVID-19.

However, no vaccine is perfect, and groundbreaking COVID-19 infections are possible in those who are vaccinated. The elderly and those who are immunocompromised may be at increased risk for these breakthrough infections.

Fortunately, fully vaccinated people usually suffer from milder COVID-19 infections. For example, a study analyzing cases of COVID-19 in England estimated that two doses of the Pfizer BioNTech vaccine is 93.7% effective in preventing symptomatic alpha variant disease and 88% effective against delta. Another study in Ontario, Canada, which has not yet been peer reviewed, found that the Moderna vaccine is 92% effective in preventing symptomatic illnesses caused by alpha.

5. How can I stay safe?

How cautious you are depends on a number of individual and external factors.

One factor is whether you are fully vaccinated. Almost all – 99.5% – of deaths from COVID-19 in the United States in recent months have been in unvaccinated people.

The most recent CDC guidelines recommend that everyone wear a mask in areas of high or high transmission, whether or not they are vaccinated. You should especially be extra careful if you are not fully vaccinated or if your immune system is weakened.

Another factor to consider is the level of community transmission and the proportion of unvaccinated people in your local community. For example, a person who lives in an area below the national average for COVID-19 vaccinations may be more likely to encounter an unvaccinated person – and therefore more likely to spread the coronavirus – than a person in an area with higher vaccination rates. .

Finally, there are still a significant number of people at high risk of COVID-19, including children. As of August 3, 2021, only 29.1% of children aged 12 to 15 and 40.4% of those aged 16 and 17 had been fully immunized.

The American Academy of Pediatrics and the Children’s Hospital Association note that a total of 4,292,120 cases of COVID-19 in children have been reported as of August 5. Children represent 14.3% of reported COVID-19 cases. If your child is not vaccinated, the best way to protect him and other unvaccinated members of your household is to get vaccinated and have everyone wear a mask in indoor public spaces.

The guidelines provided by public health agencies are just that – general guidelines. They are not designed to be prescriptive for each individual and their personal risk assessments.

Vaccines remain the best protection against all strains of the new coronavirus. But masking, social distancing and avoiding crowds and poorly ventilated indoor spaces add extra layers of protection against breakthrough infections and reduce the risk of the virus inadvertently spreading.

This story was posted from an agency feed with no text editing. Only the title has been changed.


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