The term “COVID resurgence” no longer refers to the massive waves of the early pandemic, but to periodic increases in community transmission. These increases are a predictable feature of the virus becoming endemic. Understanding this new rhythm is the first step toward navigating the ongoing challenges of COVID-19. These surges are driven by a combination of viral evolution, human immunity, and behavior.
Factors Driving the Resurgence
The primary driver of recent increases in COVID-19 cases is the continuous evolution of the virus. New variants, such as the “FLiRT” strains KP.2 and KP.3, have emerged from the previously dominant JN.1 lineage. These variants possess mutations in their spike protein that enhance their ability to evade the immune system, a concept known as immune evasion. This means people with protection from past infections or vaccinations may be more susceptible to the newer strains.
This viral evolution is compounded by the natural waning of our own immunity. Protection from either vaccination or a previous infection is not permanent and decreases over time. As antibody levels decline, individuals become more vulnerable to reinfection. Only a fraction of the population has received the most recent vaccine, further contributing to this collective vulnerability and facilitating the virus’s spread.
Seasonal and behavioral patterns also play a significant role in transmission dynamics. Increased indoor gatherings, whether during colder winter months or summer heatwaves that drive people inside, create ideal conditions for an airborne virus to spread. A general relaxation of public health precautions, such as masking and social distancing, allows the virus to move more freely through the population.
Recognizing Current COVID Infections
The symptoms associated with current COVID-19 variants largely resemble those of other common upper respiratory illnesses. The most frequently reported signs include sore throat, congestion, runny nose, cough, fatigue, and headache. Fever, chills, and body aches are also common, making it difficult to distinguish from influenza based on symptoms alone. Some individuals may also experience gastrointestinal issues like nausea or diarrhea.
A notable shift in the virus’s clinical presentation is the reduced frequency of certain hallmark symptoms from earlier in the pandemic. The loss of taste and smell, once a defining characteristic of a COVID-19 infection, is now reported much less often with the current Omicron subvariants.
For most people who have been vaccinated or previously infected, an infection with a current variant results in a mild to moderate illness, often comparable to a bad cold or the flu. The severity of symptoms can depend on a person’s underlying immunity and overall health. However, it is important to remember that even a mild case can be transmitted and cause severe illness in someone who is more vulnerable.
Modern Protective Strategies
Updated vaccinations remain a primary tool for protecting against severe outcomes from COVID-19. The 2023-2024 vaccine formula was designed to target more recent variants, like JN.1 and its descendants, including the KP.2 strain. The Centers for Disease Control and Prevention (CDC) recommends that everyone aged 6 months and older receive the updated vaccine. This is particularly advised for individuals at higher risk, such as those over 65 or with compromised immune systems, who may also be eligible for additional doses.
Beyond vaccination, non-pharmaceutical interventions continue to be effective at reducing transmission risk. Using high-quality, well-fitting masks, such as N95 or KN95 respirators, is a proven strategy, especially in crowded indoor settings, on public transportation, or when around individuals who are at high risk of severe disease.
Improving indoor air quality is another powerful protective measure. Increasing ventilation by opening windows and doors helps disperse virus particles. Using high-efficiency particulate air (HEPA) purifiers can also effectively filter viruses from the air, reducing the overall concentration of airborne pathogens in a space.
Guidelines for Testing and Treatment
If you develop symptoms of COVID-19 or have a known exposure to the virus, testing is an important step. At-home rapid antigen tests are widely available and provide quick results. For best results, it is recommended to test a few days after symptoms begin, as testing too early may yield a false negative. If an initial rapid test is negative but symptoms persist, the U.S. Food and Drug Administration (FDA) suggests retesting 48 hours later. Molecular tests, like PCR tests, are more sensitive and can be used to confirm a diagnosis.
For individuals who test positive and are at higher risk of developing severe disease, antiviral treatments are available. Medications like Paxlovid can reduce the severity of the illness and lower the risk of hospitalization. These treatments are most effective when started as soon as possible after symptoms appear. Eligibility for these treatments includes older adults and people with certain underlying health conditions. Consulting with a healthcare provider promptly after a positive test is the best way to determine if treatment is appropriate.