US FDA Accelerates Approval of New Version of COVID-19 Vaccine as Vaccination Rates Remain Low, Can Vaccine Updates Prevent Resurgence of the Pandemic?

The US Food and Drug Administration (FDA) officially approved an updated version of the COVID-19 vaccines developed by Pfizer (PFE.US) and Moderna (MRNA.US) last Thursday. The vaccine is specifically targeting the KP.2 strain, which is the offspring of the Omicron subvariant JN.1. Despite the fact that the KP.2 strain accounts for only 3% of current cases in the US, Pfizer and Moderna expect the new vaccine to be widely available in pharmacies, hospitals, and clinics across the country in the coming days.

Pfizer and Moderna stated that the new vaccine, compared to the one targeting the XBB.1.5 strain last year, can generate a stronger immune response against JN.1 and its other prevalent subtypes. Dr. Peter Marks, Director of the FDA's Center for Biologics Evaluation and Research, emphasized that given the possibility of diminishing immunity, it is crucial to receive the newer vaccine to prevent the current prevalent strain.

The US Centers for Disease Control and Prevention (CDC) recommended in June that all babies over 6 months old receive the COVID-19 vaccine, and specifically recommended that those over 12 years old receive the new vaccine, while allowing the use of the vaccine in emergency situations for children between 6 months and 11 years old. Moderna CEO Stephane Bancel stressed that timely vaccination is one of the best ways to prevent serious illness and encouraged people to consider getting the COVID-19 vaccine along with the flu vaccine. The FDA's approval was several weeks ahead of the approval on September 11, 2021.

According to data from the CDC, high levels of COVID-19 were detected in wastewater from almost all states, although other indicators of the virus were rising, the positive rate and hospitalization rate were still far below the peak levels of the epidemic. The latest data from the CDC shows that the positive rate of COVID-19 testing increased slightly from 17.9% to 18.3% in the week ending August 10. Meanwhile, the CDC reported that in some specific areas, about 4 people in every 100,000 residents were hospitalized due to COVID-19, an increase from the lowest point in May, when about 1 person in every 100,000 residents was hospitalized, reflecting the rebound trend of the epidemic in some areas.

It is worth noting that after vaccination, it usually takes two weeks for the immune response to the virus to be triggered, which means that the decline of the epidemic in the summer may be related to the vaccination schedule. Federal health officials have long stressed that COVID-19 vaccines need to be updated annually to counter new strains of the virus and weakening immunity over time.

According to CDC data, only about 22.5% of adults have received the vaccine that was released in the fall of last year. Many people said that they did not get a booster shot because they were not worried about the virus or because they were too busy to get vaccinated. In addition, the FDA required vaccine manufacturers to produce vaccines against the JN.1 strain in June and, if possible, against the KP.2 strain. This shift posed a challenge to Novavax (NVAX.US), which applied for authorization of a new JN.1 vaccine in the same month but has yet to receive FDA approval. Novavax said that it is conducting productive cooperation with the FDA and expects its vaccine to be approved before the peak vaccination period in the United States.

Novavax's vaccine is based on protein technology, which is slower to update than messenger RNA (mRNA) technology used by Pfizer and Moderna. Nevertheless, Novavax's vaccine can prevent multiple subvariants of JN.1, including KP.2.3, KP.3, KP.3.1.1 and LB.1.