Critics Argue Bird Flu Vaccine Progress Hindered by Lack of Data

Challenges in Bird Flu Tracking and Vaccine Development

Three months after a Texas dairy worker was diagnosed with bird flu, US scientists are still struggling to track the virus effectively. This difficulty hampers efforts to develop a vaccine that could prevent the virus from spreading among humans. Although the health risk to the general population is currently low, experts like vaccine developer Kate Broderick from Maravai LifeSciences Holdings express concerns about the ability to respond effectively if the virus becomes more dangerous. Broderick notes that scientists lack a clear picture of the viral strain in circulation, making it a "complete guessing game." Federal health officials aim to avoid a repetition of the 2009 H1N1 swine flu outbreak when there was a significant shortfall in vaccine doses.

The officials are utilizing lessons from the COVID-19 pandemic, particularly in viral sequencing, which helps identify new strains and update vaccines accordingly. However, collecting data has proven challenging because federal health officials need cooperation from state authorities and farm owners to test on farms. Concerns about lost milk production, estimated at $250,000 a week for a 5,000-cow farm, make farmers reluctant to increase testing. The USDA has made some progress, securing agreements with Kansas, Nebraska, New Mexico, and Texas to test bulk milk tanks on dairy farms. Michigan is also initiating efforts to detect infections among farmworkers.

Vaccine Development Obstacles

The US government has identified two potential vaccines for the current H5N1 bird flu strain and is testing them with GSK Plc, Sanofi SA, and CSL Seqirus. According to Robert Johnson of the Biomedical Advanced Research and Development Authority, the agency has stockpiled components of a potential vaccine, including antigens and adjuvants to enhance the immune response. Currently, the US has the equivalent of 10 million bird flu vaccine doses and has ordered an additional 4.8 million doses. The European Union has also secured up to 665,000 doses of CSL Seqirus’ vaccine for 15 member states, with an option to purchase as many as 40 million doses.

Nevertheless, many of these vaccines are based on older strains and may not be effective against the current version of avian flu if it begins to infect people. Broderick indicates that the current vaccines likely do not target the strain currently circulating. Developing a vaccine for a strain that spreads among humans would require rapid formulation of a new shot, according to Peter Hotez of Baylor College of Medicine. Moderna Inc. and Pfizer Inc. are in talks with the US government to develop mRNA-based bird flu vaccines, which offer quicker updates compared to traditional vaccines grown in chicken eggs. Results from Moderna’s early-stage trial are expected soon.

Predicting a virus variant that spreads among humans remains a significant challenge, says Michael Osterholm of the University of Minnesota’s Center for Infectious Disease Research and Policy. The question remains whether vaccine production should wait until a pandemic virus emerges. A CDC spokesperson maintains that the agency has an "up-to-date picture of the virus with widespread surveillance," and companies like GSK, CSL Seqirus, and Sanofi assert that their vaccines could cope with the current strains.