Thanks to COVID-19 vaccines, coronavirus infections have been steadily declining across the U.S. Will the virus’ highly contagious variants reverse that trend and cause another surge in infections?
That’s a definite concern among medical experts in the U.S.
“The COVID-19 Delta variant swept through India this spring, causing a massive surge in cases and thousands of deaths,” explained Sarasota Memorial Infectious Disease specialist Manuel Gordillo, MD. “Since then, it has spread to more than 80 countries, including the U.S.
Last week, the federal Centers for Disease Prevention and Control (CDC) and other public health experts issued a strong warning about the highly transmissible Delta variant and the risks it poses to people who aren’t fully vaccinated.
“The key in preventing outbreaks of the Delta and other COVID-19 variants is getting more people fully vaccinated,” Dr. Gordillo said.
The Delta variant spreads quickly in areas with higher rates of unvaccinated people. In fact, since it was first identified in Florida (March 16), cases have doubled about every 2 weeks. If vaccination rates continue to lag across the state, we could see COVID-19 infections start to rise again as early as July, public health officials project.
What is the Delta Variant?
Viruses constantly change, or mutate. A virus is deemed a variant when it has at least 1 genetic mutation setting it apart from the original strain and from other viral variants.
The COVID-19 Delta variant is just one of many mutated strains of the SARS-CoV-2 virus that have emerged during the pandemic, but health experts have warned that the highly transmissable Delta poses the greatest risk to containing the coronavirus worldwide.
The Delta strain — which accounted for 40% of new COVID-19 cases in the U.S. as of July 27 — is now the dominant variant and has led to at least 1 more mutation — the Delta Plus — that health officials are monitoring but have not yet classified as a "variant of concern."
Delta Variant: What You Need to Know
Highly Contagious: 60% more transmissible than the Alpha variant (first identified in the UK), which was more contagious than the original viral strain that emerged from Wuhan, China.
Less Responsive to Treatment: The CDC noted the Delta mutation doesn't respond as well to monoclonal antibody treatments.
Increased Hospitalizations: Studies in England show the Delta strain has resulted in more hospitalizations among COVID-19 patients, but no more deaths than caused by previous variants.
Vaccine Effectiveness: All of the COVID-19 vaccines authorized for use in the U.S. appear to provide protection against all current variants, including Delta.
“We have no reason to think that the Delta variant is not circulating in our area, though no reports have been shared publicly,” said Dr. Gordillo. “The Florida Department of Health, with recommendations from the CDC, decides which coronavirus test samples undergo whole genome sequencing to determine whether they're variant cases.”
Those results are used for public health surveillance and epidemiologic investigations.
Who’s Most at Risk of Delta Variant Infection?
Like all other COVID-19 variants identified so far, the Delta strain does not pose much risk to people who have been fully vaccinated.
However, people who aren’t fully vaccinated (2 weeks post final dose) and those with compromised immune systems are at high risk for infection from the contagious Delta strain.
Which COVID-19 Vaccines Protect Against the Delta Variant?
“All of the COVID-19 vaccines authorized for use in the U.S. appear to provide protection against all the variants, including Delta,” Dr. Gordillo said.
Studies indicate that the Pfizer-BioNTech vaccine is about 88% effective against the Delta strain (2 weeks after final dose), and researchers expect similar results to be announced from Moderna vaccine studies. The single-dose Johnson & Johnson-Janssen vaccine appears to be about 60% effective against the Delta strain.
Does the Delta Variant Affect Children?
The Delta variant appears to be worse than the original COVID-19 strain and other variants in terms of contagiousness and severity, but evidence suggests that it rarely causes serious illness in children.
“Data from England, where the Delta variant is widespread, shows that COVID-related hospitalizations of children have risen in recent weeks, but those increases have been modest,” explained Dr. Gordillo.
Children ages 12 and older are eligible for vaccination, and experts agree that the vaccine’s benefits in protecting youth against the short- and long-term impacts of COVID-19 infection far outweigh any potential risks.
For those too young to be vaccinated, we recommend continuing precautions, like wearing masks indoors in public places and avoiding crowds.
Protect Yourself & Your Loved Ones
The safest way to protect yourself against COVID-19 and its variants is to get vaccinated.
“Anyone who is not fully vaccinated should continue to wear masks indoors, and to practice hand-hygiene and social-distancing in public places until 2 weeks have passed since their final vaccine dose,” Dr. Gordillo advised.
Because we don’t yet know how effective the vaccines are for immunocompromised people, those with autoimmune diseases and weakened immune systems should continue to follow all CDC guidance for COVID-19 prevention, as they are at higher risk for severe complications from COVD-19 infection.
It's important to note that individuals who test positive for COVID-19 are advised to take the same precautions of isolation, mask-wearing indoors and hand-washing, regardless of which strain they carry.
** NOTE: This content was originally posted June 29, 2021, and was last updated July 2, 2021. Information related to COVID-19 and COVID-19 vaccines is continually evolving. For the most up to date info, we recommend visiting cdc.gov.