Federal health officials have recently provided new recommendations regarding COVID-19 vaccinations for individuals who are overweight or obese and have experienced breakthrough SARS-CoV-2 infections despite being fully vaccinated. The U.S. Centers for Disease Control and Prevention (CDC) now suggests that using longer needles may be crucial for the effectiveness of the vaccine in these cases.
This updated guidance, coming over two years after the initial rollout of mRNA shots, advises vaccine administrators to consider employing a 1.5-inch needle, rather than the standard one-inch needle, especially for vaccines given to individuals with higher body mass.
The rationale behind this recommendation lies in the anatomy of the deltoid muscle, where intramuscular shots for COVID-19, influenza, and tetanus are administered. Given that this muscle is located beneath layers of skin, fat, and connective tissue that can vary in thickness from person to person, the CDC emphasizes the need for different needle sizes to ensure effective vaccine delivery.
According to Dr. Matthew Laurens, who leads studies at the University of Maryland’s Center for Vaccine Development, using the right needle length is crucial for advancing the needle beyond the subcutaneous layer, thereby ensuring effective vaccine administration. Additionally, it can help reduce the likelihood of adverse effects like swelling or redness at the vaccination site.
While using an incorrect needle size might potentially reduce vaccine efficacy, experts emphasize that it doesn’t necessarily mean a total loss of protection. Dr. Amesh Adalja, an expert in biosecurity and emerging infectious diseases at Johns Hopkins Bloomberg School of Public Health, explains that even if the vaccine doesn’t entirely reach the muscle, there will likely still be an immune response. Therefore, while it might not offer as much protection as it could with the correct needle length, some level of safeguarding against the virus is still expected.
Despite these important recommendations, there are concerns among experts that they might not be consistently implemented in medical settings. This raises a call for patients to advocate for themselves and ensure that the appropriate needle length is used for their body type when receiving vaccines. This suggestion aligns with recent data showing a significant increase in medical errors among overworked physicians during the COVID-19 pandemic, emphasizing the importance of personal oversight in medical care.