The arrival of this year's updated Covid-19 vaccines at pharmacies will be delayed compared to the previous year, despite the increasing rates of Covid-19 in hospitals nationwide.

According to U.S. regulators, the updated vaccines are expected to be available in "mid-to-late September." This represents a shift from previous guidance provided by the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA), as Dr. Mandy Cohen, the new director of the CDC, initially stated that the doses wouldn't arrive until "early October."

Both timelines indicate a slower rollout compared to the previous year. Interestingly, the variant that the updated vaccines were specifically designed to target has already largely disappeared from the U.S. While the vaccine manufacturers and the FDA assure that the updated vaccines will also protect against the currently dominant variants, the situation is rapidly evolving.

Moderna spokesman Christopher Ridley stated on Thursday, "We are working closely with public health officials and regulators to ensure the vaccine is available as soon as possible."

Pfizer confirmed that they will be ready to ship doses to pharmacies and healthcare providers by the end of August, while Moderna announced that their doses had already been manufactured and were ready for immediate shipment.

Although Covid-19 hospitalizations are increasing in the U.S., they are still relatively low compared to previous points during the pandemic. According to the CDC, 12,600 people were admitted to U.S. hospitals in the week ending August 12, with a positive Covid-19 diagnosis, which reflects a 21.6% increase from the previous week.

Furthermore, the variant landscape is continuously changing. In June, the FDA requested that drug developers update their Covid-19 vaccines to target the variant known as XBB.1.5, which, at the time, was responsible for the majority of U.S. cases. However, its dominance has since diminished, and the CDC now estimates that it accounts for only 4.7% of U.S. cases. The largest shares are now attributed to variants known as EG.5 and FL. 1.5.1.

New Boosters Show Promising Results

Both Moderna and Pfizer have announced positive results for their updated Covid-19 booster shots. Moderna's booster demonstrated an immune response to EG.5, while also increasing neutralizing antibodies against FL.1.5.1.

A Delayed Strategy

The release of these new boosters raises questions about the federal government's approach to annual Covid-19 booster shots. Modeled after the strategy used for influenza vaccines, this new approach has yet to align with the unpredictable nature of Covid-19.

In previous years, influenza followed a consistent seasonal pattern, allowing for a late September rollout of boosters that would coincide with the anticipated surge in cases during December or January. However, Covid-19 does not adhere to the same predictable timeline.

Waiting Game

As a result, vulnerable populations, particularly older adults, are now left waiting for weeks while the boosters sit in warehouses. These boosters offer an opportunity for increased protection against the virus, but their potential value may diminish as new variants emerge.

Government Guidance

Both agencies have referenced a guide issued by the Health and Human Services Department in July, which suggests a "mid to late September" rollout for the vaccines.

Market Response

Investors have taken notice of these developments, leading to a 13.5% increase in Moderna's shares and a 14.8% increase in shares of Pfizer partner BioNTech over the past 10 days. Concerns over the spread of the virus have prompted speculation regarding vaccine sales estimates. However, both companies have tempered investor expectations during recent earnings calls in August.