COVID-19 Vaccines to Undergo Major Change This Fall
The COVID-19 vaccines will soon undergo a significant modification as new variants continue to emerge.
Scientific Advisers Reviewing the Need for Updated Vaccines
The scientific advisers to the Food and Drug Administration (FDA) met on Thursday to evaluate whether the upcoming round of COVID-19 injections in the United States should solely focus on protecting against the newer and more dominant variants. The primary concern is a viral branch called XBB, which belongs to the omicron family tree and is currently prevalent worldwide.
Winter Concerns regarding Evolving Virus
Dr. Peter Marks, the FDA vaccine chief, expressed concerns over the potential resurgence of the virus during the winter, when both the virus and the population’s immunity may have further evolved. As people tend to move indoors during this season, the risk of another wave of COVID-19 infections remains high.
What You Need to Know
Here are some key points to be aware of:
Why Another Round of Vaccines?
The FDA has advised Americans to anticipate an updated vaccine against COVID-19 this fall, similar to the annual flu shot. Although a significant portion of the population has either been infected or received at least one round of vaccinations, the virus continues to generate new variants.
The current vaccines being administered in the US are combination shots from Pfizer and Moderna, which provide protection against the original strain as well as the BA.4 and BA.5 variants of omicron, the most common variants from last year. However, only 17% of Americans have received the combined booster dose.
Additionally, while high-risk individuals and seniors were authorized to receive an extra booster dose earlier this year, most individuals will have a significant gap between their last shot and the fall season.
Enhancing Protection Against New Variants
With the emergence of omicron last year, a combination shot was considered the safest option when updating the vaccine due to the uncertainty surrounding the duration of the new variant and the potential characteristics of future variants. However, Dr. Rachel Presti, an infectious disease specialist at Washington University in St. Louis, suggests that keeping the original strain in the vaccine provides no significant advantage. In fact, repeated exposure to the original strain could lead to an “impression” disadvantage, where the immune system responds more robustly to the parent strain than to the new booster dose.
Hence, the FDA is inclined to remove the original strain and select a fall vaccine recipe that exclusively targets the XBB variant. The goal is to prompt the immune system to produce cross-protective antibodies that combat a wider range of viruses. Similar recommendations have been recently made by vaccine advisers from the World Health Organization and European regulators.
Predicting Winter Outbreaks
Another challenge lies in determining which specific variant of XBB to target, as the currently dominant variant is expected to undergo further mutations by the winter season. Regulators will make their best prediction, similar to the yearly selection process for the flu vaccine.
Debates on Additional Shots
The FDA advisers will also debate the number of additional shots required. Older adults and individuals with weakened immune systems remain at the highest risk of hospitalization due to COVID-19, even with declining cases. One question is whether they should receive a single vaccine or be eligible for multiple doses. Additionally, the recommended number of doses for young children who have never been vaccinated will also be discussed. The Centers for Disease Control and Prevention will have the final authority in making these recommendations.