A surge in COVID-19 infections has swept the country this summer, defying expectations of a decline and fueling concerns about the spread of new variants. While the Centers for Disease Control and Prevention (CDC) no longer tracks individual infection numbers, experts believe that this wave could be the most significant one yet.

The rise in cases can be attributed to a combination of factors, including increased travel and extreme hot weather driving more people indoors. Additionally, a trio of variants, accounting for almost 70 percent of all infections, have contributed to the surge. However, it is important to note that these variants have not been proven to cause more severe illnesses, and current vaccines remain effective against them.

Wastewater data from the CDC indicates that the highest viral activity is currently concentrated in the West. However, a "high" or "very high" level of the COVID-19 virus has been detected in almost every state's wastewater. Furthermore, viral levels are significantly higher nationwide compared to the same period last year, and the increase in infections began earlier in the summer.

Tracking levels of viral activity through wastewater data has become the most reliable method, as testing has declined due to both pandemic fatigue and limited access to free at-home tests. The government is no longer distributing these tests, and private insurance plans are not required to cover them since the public health emergency ended in 2023.

While vaccines and antivirals have helped mitigate the severity of the virus and prevent overwhelming hospitalizations, there remains a sizable portion of the population that has not received updated vaccinations. This raises concerns about the potential for more dangerous variants to gain a foothold, especially among high-risk individuals such as those over 65 or with preexisting conditions.

Experts emphasize the need for continued vigilance, particularly for vulnerable populations. Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University, highlights the persistent contagiousness of the virus and urges those at higher risk to take precautions such as wearing masks when in crowded indoor spaces.

Hospitalizations have been steadily increasing in certain regions for at least five weeks, surprising experts who expected the summer increase to plateau and eventually decline. This ongoing surge has prompted some communities to overlook the severity of the pandemic, treating COVID-19 as just another respiratory virus.

President Biden, for instance, recently tested positive for COVID-19 despite being fully vaccinated. Although he received an updated vaccine last fall, it is unclear if he received a follow-up dose as recommended by the CDC for older individuals. Updated vaccines targeting current variants are expected to be available later this fall, and the CDC recommends that everyone aged 6 months and older should receive them.

As of May, only 22.5 percent of adults in the United States reported having received the updated 2023-2024 vaccine, which was tailored to the dominant XBB variant at that time. While the immunity conferred by older vaccines may wane over time, it still provides some level of protection, albeit reduced. Individuals with healthy immune systems who have been previously vaccinated or infected are still at lower risk for severe infections requiring hospitalization or resulting in death.

Overall, experts stress the need for continued caution, especially among those who are most at risk. Though the country may have moved on from the pandemic, the resilient variants and decreased testing heighten the need to remain vigilant and prioritize public health measures to mitigate the impact of COVID-19.