COVID variants have shaped the pandemic since the early days of the virus. Because of this, it helps to know how variants form, how they spread, and what they mean for testing and treatment. In this article, we share insights from Dr. Jeffrey Klausner, a clinical professor of Medicine at USC. He is also an advisor to the CDC and WHO. Below, we explain what COVID variants are, why they matter, and when to get tested at CityHealth Urgent Care.
What Are COVID Variants and Why Do They Matter?
COVID-19 comes from the SARS-CoV-2 virus. Essentially, this virus changes a little each time it copies itself inside a human cell. Most of these changes are harmless. However, some changes occur in the spike protein, which is how the virus enters the body. Specifically, these changes can make the virus spread faster or dodge the immune system better.
Eventually, when enough changes build up, scientists call the new form a “variant.” In other words, a variant is not a brand-new virus. Instead, it is a slightly different version of the same virus. Indeed, even small shifts in the spike protein can have big effects on how fast a variant spreads.
Furthermore, Dr. Klausner points out that a variant is not the same as a full mutation. A full mutation could turn the germ into something else entirely. But COVID variants are smaller changes in the spike protein. They still belong to the SARS-CoV-2 family.
How COVID Variants Emerge Through Viral Mutation
Every time SARS-CoV-2 copies itself, there is a small chance of an error in the genetic code. These errors are called mutations. Typically, most errors do nothing, or they even weaken the virus. But once in a while, an error helps the virus. For example, it might bind to human cells more tightly or partly escape antibodies.
Moreover, variants tend to appear when the virus spreads widely among large groups of people who are not vaccinated. The more the virus copies itself, the more chances it has to pick up helpful errors. For this reason, health officials have pushed for global vaccination. Slowing the spread also slows the rise of new COVID variants.
Additionally, long-lasting infections in people with weak immune systems can speed up this process. In these cases, the virus has more time to change. Sometimes it picks up many mutations in a single person.
Notable COVID Variants: From Alpha to Omicron and Beyond
Since the original SARS-CoV-2 strain appeared in late 2019, several major variants have been named. Here is a quick look at the most important ones, listed in order:
Alpha (B.1.1.7): First found in the United Kingdom in late 2020. Alpha was about 50% more likely to spread than the original strain. As a result, it quickly took over around the world before Delta replaced it.
Delta (B.1.617.2): First found in India in late 2020 and labeled a variant of concern in mid-2021. Delta spread much faster than Alpha. In particular, Dr. Klausner noted that people with Delta carried more virus in their nose and throat. This made it much easier to pass on. Overall, Delta showed how fast COVID variants can shift the course of a pandemic.
Omicron (B.1.1.529): First reported in South Africa in November 2021. Omicron had over 30 changes in the spike protein alone. Consequently, it spread far more easily than Delta. On the bright side, it often caused milder illness. Omicron led to many sub-types (BA.1, BA.2, BA.5, XBB, and others).
Later variants (2023-2025): Since Omicron, more sub-types and mixed strains have appeared. While none spread as fast as Omicron did, they have gotten better at dodging the immune system. Because of this, updated vaccines and boosters now target the latest strains. Notably, health experts still watch for new COVID variants that may pose a higher risk.
What COVID Variants Mean for Testing and Treatment
Of course, a common question is whether current COVID tests still work on newer variants. The short answer is yes. Most PCR and rapid antigen tests look for parts of the virus that stay the same across variants. However, some rapid tests may be less accurate for heavily changed strains. Therefore, if you have symptoms but test negative on a rapid test, follow up with a PCR test to be sure.
In terms of treatment, COVID variants have changed which drugs work best. For instance, some antibody treatments that helped against early strains stopped working against Omicron. On the other hand, antiviral pills like Paxlovid have stayed effective against most variants. This is because they target the way the virus copies itself, not the spike protein.
Similarly, updated vaccines are redesigned on a regular basis to match circulating variants more closely. The CDC recommends staying up to date with shots as one of the best ways to stay protected.
When to Get Tested for COVID at CityHealth
Because COVID variants still circulate, knowing when to test is important. You should think about getting a COVID test if:
- Symptoms: Fever, cough, sore throat, body aches, loss of taste or smell, or trouble breathing.
- Known exposure: You were near someone who tested positive in the past 5 days.
- Before gatherings: You plan to visit elderly or high-risk family members.
- Travel: Some places still ask for proof of a negative test.
- Work rules: Your job requires testing after illness or contact with a positive case.
At CityHealth Lab Testing Services, we offer same-day COVID testing with quick results. Both PCR and rapid antigen tests are on hand. Walk-ins are welcome at our Oakland (Montclair Village) and San Leandro clinics. You can also book online for a shorter wait.
Frequently Asked Questions About COVID Variants
Are COVID variants more dangerous than the original strain?
Not always. Some variants, like Delta, caused worse illness on average. Others, like Omicron, spread more easily but were often milder. However, any variant can still cause serious illness in people who are not vaccinated or have weak immune systems. Therefore, staying current with vaccines and testing when sick is always a good idea.
Do COVID tests still work for newer variants?
Yes. Most PCR and rapid antigen tests still detect current variants well. PCR tests target stable parts of the virus, so they stay reliable as the spike protein changes. If you get a negative rapid test but still feel sick, consider a PCR test at CityHealth.
How often do new COVID variants appear?
New variants can show up at any time because the virus keeps changing as it spreads. Since 2020, major variants have popped up every few months. The WHO tracks all variants and rates them based on their public health risk.
Should I get a booster shot for the latest variant?
Yes, the CDC says eligible people should get updated boosters. These shots are made to match the newest strains. Even if you have had COVID before, a booster can strengthen your defenses. Visit CityHealth Urgent Care to ask about vaccine options.
Stay Informed, Stay Protected
COVID variants will likely keep changing as long as the virus spreads around the world. Although the pandemic has moved from crisis mode to a more steady state, staying informed about new variants still matters. So does keeping your vaccines current and testing when needed.
Above all, Dr. Klausner’s advice from 2021 still applies: vaccination is the most important tool we have. In addition, easy access to testing helps you catch infections early, protect the people around you, and start treatment fast.
Follow the CityHealth blog for updates on COVID variants, testing, and community health. You can also find expert interviews on the CityHealth YouTube channel.
Need a COVID test or have questions about variants?
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